Drugs Related to Central Nervous System MBBS Notes | EduRev

MBBS : Drugs Related to Central Nervous System MBBS Notes | EduRev

 Page 1


Pharmacology Handout – Level Two 
 
DRUGS RELATED TO CENTRAL NERVOUS SYSTEM 
HYPNOTICS AND ANXIOLYTICS 
These will induce sleep at night and sedate during the day.  Dependence (physical and psychological) and 
tolerance occur.  This can account for the difficulty when withdrawing the drug.  Benzodiazepines can 
have a paradoxical effect increasing hostility and aggression – doses need to adjusted up as well as down.  
Barbiturates and alcohol make the situation worse.  Abrupt withdrawal can cause confusion and 
psychosis.  This can develop up to three weeks after stopping benzodiazepines.  Signs – insomnia, 
anxiety, decrease appetite, tremor.  Withdraw by decreasing daily dose by one eighth every two weeks – 
can take months.  Beta blockers may be needed to control symptoms, avoid anti-psychotics.  Before 
prescribing hypnotics try and treat underlying factors causing insomnia.  In short term insomnia a 3 week 
course should not be exceeded.  Chronic insomnia related to anxiety and depression should be addressed 
by treating the underlying condition, use of hypnotics to alleviate symptoms.  Tolerance to hypnotics 
occurs in 3-14 days of continuous use, withdrawal can cause rebound insomnia.  Hypnotics should be 
avoided in the elderly – confusion and ataxia common. 
Benzodiazepines 
Nitrazepam – may have residual effect next day.  Beware respiratory disease, alcohol, elderly, hepatic 
and renal disease.  Drowsiness and light-headedness next day, confusion and ataxia in the elderly and 
amnesia.  5-10mg at bedtime; elderly 2.5-5mg.   
Temazepam – shorter acting with little hangover effect.  Equivalent dose 10mg = 5mg nitrazepam.  10-
20mg at bedtime, exceptionally 30-40mg.  Elderly 10mg bedtime. 
Others 
Zolpidem – acts at the same receptors but is not a benzodiazepine.  Short duration, no hangover.  Not 
licensed for long term use.  Beware depression, respiratory disease, alcohol, elderly, hepatic and renal 
disease.  Can cause diarrhoea, N&V, headache, drowsiness, dependence, nightmares, double vision, 
tremor.  10mg bedtime, elderly 5mg.       
Zopiclone – similar to zolpidem with dry mouth, metallic taste.  7.5mg bedtime, elderly 3.75mg. 
Chloral Hydrate – same cautions, can cause gastric irritation and eosinophilia as well.  500-1000mg 
with plenty of water at bedtime.  Child 30-50mg/kgm, maxm 1000mg.   
 
KEY POINTS – HYPNOTICS 
1. Give 30 minutes before going to bed (zolpidem is taken immediately before retiring – fast onset) 
2. Low initial dose especially in the elderly 
3. Limit treatment to 2-3 weeks, preferably alternate nights 
4. If dependence, withdraw slowly to avoid symptoms of withdrawal 
5. Onset of drug-induced sleep may be followed by a deterioration of patient’s condition  
  
ANXIOLYTICS 
Treatment of stress related symptoms.  Not appropriate for depression and chronic psychosis.  In 
bereavement psychological adjustment may be inhibited by benzodiazepines.  Lowest possible dose for 
shortest possible time.  Dependence likely in alcoholics, drug abuse and personality disorders.   
Benzodiazepines 
Short term relief of severe anxiety.  Diazepam has sustained action and lorazepam is shorter acting.  
Lorazepam has been used in panic disorders and control of panic attacks.   
Diazepam – used in short term anxiety, alcohol withdrawal, status epilepticus, febrile convulsions, 
muscle spasms.  Beware respiratory disease, muscle disorders (relaxant effect), alcohol abuse, personality 
disorders.  Drowsiness and light-headedness next day, confusion and ataxia, amnesia, dependence, 
paradoxical aggression, muscle weakness, GIT and visual disturbance and tremor.  2mg TDS orally, 
Page 2


Pharmacology Handout – Level Two 
 
DRUGS RELATED TO CENTRAL NERVOUS SYSTEM 
HYPNOTICS AND ANXIOLYTICS 
These will induce sleep at night and sedate during the day.  Dependence (physical and psychological) and 
tolerance occur.  This can account for the difficulty when withdrawing the drug.  Benzodiazepines can 
have a paradoxical effect increasing hostility and aggression – doses need to adjusted up as well as down.  
Barbiturates and alcohol make the situation worse.  Abrupt withdrawal can cause confusion and 
psychosis.  This can develop up to three weeks after stopping benzodiazepines.  Signs – insomnia, 
anxiety, decrease appetite, tremor.  Withdraw by decreasing daily dose by one eighth every two weeks – 
can take months.  Beta blockers may be needed to control symptoms, avoid anti-psychotics.  Before 
prescribing hypnotics try and treat underlying factors causing insomnia.  In short term insomnia a 3 week 
course should not be exceeded.  Chronic insomnia related to anxiety and depression should be addressed 
by treating the underlying condition, use of hypnotics to alleviate symptoms.  Tolerance to hypnotics 
occurs in 3-14 days of continuous use, withdrawal can cause rebound insomnia.  Hypnotics should be 
avoided in the elderly – confusion and ataxia common. 
Benzodiazepines 
Nitrazepam – may have residual effect next day.  Beware respiratory disease, alcohol, elderly, hepatic 
and renal disease.  Drowsiness and light-headedness next day, confusion and ataxia in the elderly and 
amnesia.  5-10mg at bedtime; elderly 2.5-5mg.   
Temazepam – shorter acting with little hangover effect.  Equivalent dose 10mg = 5mg nitrazepam.  10-
20mg at bedtime, exceptionally 30-40mg.  Elderly 10mg bedtime. 
Others 
Zolpidem – acts at the same receptors but is not a benzodiazepine.  Short duration, no hangover.  Not 
licensed for long term use.  Beware depression, respiratory disease, alcohol, elderly, hepatic and renal 
disease.  Can cause diarrhoea, N&V, headache, drowsiness, dependence, nightmares, double vision, 
tremor.  10mg bedtime, elderly 5mg.       
Zopiclone – similar to zolpidem with dry mouth, metallic taste.  7.5mg bedtime, elderly 3.75mg. 
Chloral Hydrate – same cautions, can cause gastric irritation and eosinophilia as well.  500-1000mg 
with plenty of water at bedtime.  Child 30-50mg/kgm, maxm 1000mg.   
 
KEY POINTS – HYPNOTICS 
1. Give 30 minutes before going to bed (zolpidem is taken immediately before retiring – fast onset) 
2. Low initial dose especially in the elderly 
3. Limit treatment to 2-3 weeks, preferably alternate nights 
4. If dependence, withdraw slowly to avoid symptoms of withdrawal 
5. Onset of drug-induced sleep may be followed by a deterioration of patient’s condition  
  
ANXIOLYTICS 
Treatment of stress related symptoms.  Not appropriate for depression and chronic psychosis.  In 
bereavement psychological adjustment may be inhibited by benzodiazepines.  Lowest possible dose for 
shortest possible time.  Dependence likely in alcoholics, drug abuse and personality disorders.   
Benzodiazepines 
Short term relief of severe anxiety.  Diazepam has sustained action and lorazepam is shorter acting.  
Lorazepam has been used in panic disorders and control of panic attacks.   
Diazepam – used in short term anxiety, alcohol withdrawal, status epilepticus, febrile convulsions, 
muscle spasms.  Beware respiratory disease, muscle disorders (relaxant effect), alcohol abuse, personality 
disorders.  Drowsiness and light-headedness next day, confusion and ataxia, amnesia, dependence, 
paradoxical aggression, muscle weakness, GIT and visual disturbance and tremor.  2mg TDS orally, 
increasing to 15-30mg daily.  Elderly, half adult dose.  Suppository 10-30mg.  IV 5mg/minute into a large 
vein up to 10mg, repeat in 4 hours.   
Lorazepam – similar problems.  1-4mg daily in divided doses.  Elderly half adult dose.  IV 25-30mcg/kg 
repeated every 6 hours into large vein. 
 
KEY POINTS – BENZODIAZEPINES 
1. Normally for short term treatment only 
2. Drowsiness is a side effect – warn car drivers 
3. Alcohol may have additive effects and should be avoided 
4. Withdrawal of treatment should be slow 
  
ANTIPSYCHOTICS 
These drugs are also known as neuroleptics and major tranquillisers.  In the short term these drugs are 
used to quieten disturbed patients whatever the underlying psychopathology.  In schizophrenia these 
drugs relieve the florid psychotic symptoms such as hallucinations and delusions.  Less useful in 
withdrawn apathetic patients.  Long term treatment may be necessary.  Work by blocking D
2
 receptors 
and may therefore produce extrapyramidal side effects.  Caution in liver and renal disease, Parkinson’s, 
CVS disease, epilepsy, depression, prostatic problems.  EPSE – tremor, dystonia (abnormal face and body 
movements), dyskinesia, akathisia and tardive dyskinesia.  Drowsiness, apathy, convulsion, headache, 
confusion, hypotension, tachycardia.  Neuroleptic malignant syndrome – hyperthermia, rigidity, 
autonomic dysfunction.  The atypical antipsychotics are better tolerated and EPSE less frequent.  
 
NICE Guidelines Anti-Psychotics 
 
Established anti-psychotics cost £70 per person per year.  Side effects include shaking, spasms, blurred 
vision, dry mouth, weight gain and fits.  New atypical anti-psychotics as effective with fewer side effects 
but cost £1,220 per person per year.  Theoretically less admissions with atypicals, overall cost cheaper.  
Lack of satisfactory improvement despite sequential use of the recommended doses for 6-8 weeks of at 
least two anti-psychotics, at least one being atypical – then use clozapine at the earliest opportunity.  
Atypicals include amisulpride, olanzapine, quetiapine, risperidone and zotepine.  These drugs should be 
first line in newly diagnosed schizophrenics.  Compliance improved with depot preparations.  
 
Risperidone – similar side effects and hyponatraemia.  Dose 2mg in 1-2 divided doses on first day then 
4mg in 1-2 divided doses on day two – range 4-6mg daily. 
Olanzapine – caution in prostatic problems, paralytic ileus, diabetes mellitus, bone marrow depression.  
Contraindicated in closed angle glaucoma.  Side effects – anti-muscarinic, drowsy, exacerbation of 
Parkinson’s, blood dyscrasias and speech difficulties.  Dose 10mg daily to a maximum of 20mg. 
Quetiapine – similar side effects and prolonged QT interval.  Dose 25mg twice daily on day one; 50mg 
twice dailyon day two; 100mg twice daily on day three; 150mg twice daily on day four then adjust – 
range 300-450mg daily.   
Haloperidol – caution with hypocalcaemia and hypokalaemia.  Fewer anti-muscarinic side effects and 
hypotension, less sedating but EPSE.  Dose initially 1.5-3mg 2-3 times daily or 3-5mg 2-3 times daily in 
severely affected patients.  Elderly half dose.  IM/IV 5-10mg. 
Flupentixol – avoid in porphyria, less sedating, increased EPSE.  Initial dose 3-9mg twice daily to a 
maximum of 18mg daily.  Elderly 25-50% adult dose. 
Chlorpromazine – hypotension and tachycardia.  In schizophrenia oral dose 25mg three times daily to a 
maintenance dose of 75-300mg daily.  30-50% dose in the elderly.  Can be given IM and PR as well. 
Amisulpride – beware Parkinson’s disease.  Insomnia, anxiety, agitation, N&V, constipation, dry mouth.  
Acute attack – 400-800mg daily in two doses, maxm 1.2g daily.  Negative symptoms 50-300mg daily. 
Page 3


Pharmacology Handout – Level Two 
 
DRUGS RELATED TO CENTRAL NERVOUS SYSTEM 
HYPNOTICS AND ANXIOLYTICS 
These will induce sleep at night and sedate during the day.  Dependence (physical and psychological) and 
tolerance occur.  This can account for the difficulty when withdrawing the drug.  Benzodiazepines can 
have a paradoxical effect increasing hostility and aggression – doses need to adjusted up as well as down.  
Barbiturates and alcohol make the situation worse.  Abrupt withdrawal can cause confusion and 
psychosis.  This can develop up to three weeks after stopping benzodiazepines.  Signs – insomnia, 
anxiety, decrease appetite, tremor.  Withdraw by decreasing daily dose by one eighth every two weeks – 
can take months.  Beta blockers may be needed to control symptoms, avoid anti-psychotics.  Before 
prescribing hypnotics try and treat underlying factors causing insomnia.  In short term insomnia a 3 week 
course should not be exceeded.  Chronic insomnia related to anxiety and depression should be addressed 
by treating the underlying condition, use of hypnotics to alleviate symptoms.  Tolerance to hypnotics 
occurs in 3-14 days of continuous use, withdrawal can cause rebound insomnia.  Hypnotics should be 
avoided in the elderly – confusion and ataxia common. 
Benzodiazepines 
Nitrazepam – may have residual effect next day.  Beware respiratory disease, alcohol, elderly, hepatic 
and renal disease.  Drowsiness and light-headedness next day, confusion and ataxia in the elderly and 
amnesia.  5-10mg at bedtime; elderly 2.5-5mg.   
Temazepam – shorter acting with little hangover effect.  Equivalent dose 10mg = 5mg nitrazepam.  10-
20mg at bedtime, exceptionally 30-40mg.  Elderly 10mg bedtime. 
Others 
Zolpidem – acts at the same receptors but is not a benzodiazepine.  Short duration, no hangover.  Not 
licensed for long term use.  Beware depression, respiratory disease, alcohol, elderly, hepatic and renal 
disease.  Can cause diarrhoea, N&V, headache, drowsiness, dependence, nightmares, double vision, 
tremor.  10mg bedtime, elderly 5mg.       
Zopiclone – similar to zolpidem with dry mouth, metallic taste.  7.5mg bedtime, elderly 3.75mg. 
Chloral Hydrate – same cautions, can cause gastric irritation and eosinophilia as well.  500-1000mg 
with plenty of water at bedtime.  Child 30-50mg/kgm, maxm 1000mg.   
 
KEY POINTS – HYPNOTICS 
1. Give 30 minutes before going to bed (zolpidem is taken immediately before retiring – fast onset) 
2. Low initial dose especially in the elderly 
3. Limit treatment to 2-3 weeks, preferably alternate nights 
4. If dependence, withdraw slowly to avoid symptoms of withdrawal 
5. Onset of drug-induced sleep may be followed by a deterioration of patient’s condition  
  
ANXIOLYTICS 
Treatment of stress related symptoms.  Not appropriate for depression and chronic psychosis.  In 
bereavement psychological adjustment may be inhibited by benzodiazepines.  Lowest possible dose for 
shortest possible time.  Dependence likely in alcoholics, drug abuse and personality disorders.   
Benzodiazepines 
Short term relief of severe anxiety.  Diazepam has sustained action and lorazepam is shorter acting.  
Lorazepam has been used in panic disorders and control of panic attacks.   
Diazepam – used in short term anxiety, alcohol withdrawal, status epilepticus, febrile convulsions, 
muscle spasms.  Beware respiratory disease, muscle disorders (relaxant effect), alcohol abuse, personality 
disorders.  Drowsiness and light-headedness next day, confusion and ataxia, amnesia, dependence, 
paradoxical aggression, muscle weakness, GIT and visual disturbance and tremor.  2mg TDS orally, 
increasing to 15-30mg daily.  Elderly, half adult dose.  Suppository 10-30mg.  IV 5mg/minute into a large 
vein up to 10mg, repeat in 4 hours.   
Lorazepam – similar problems.  1-4mg daily in divided doses.  Elderly half adult dose.  IV 25-30mcg/kg 
repeated every 6 hours into large vein. 
 
KEY POINTS – BENZODIAZEPINES 
1. Normally for short term treatment only 
2. Drowsiness is a side effect – warn car drivers 
3. Alcohol may have additive effects and should be avoided 
4. Withdrawal of treatment should be slow 
  
ANTIPSYCHOTICS 
These drugs are also known as neuroleptics and major tranquillisers.  In the short term these drugs are 
used to quieten disturbed patients whatever the underlying psychopathology.  In schizophrenia these 
drugs relieve the florid psychotic symptoms such as hallucinations and delusions.  Less useful in 
withdrawn apathetic patients.  Long term treatment may be necessary.  Work by blocking D
2
 receptors 
and may therefore produce extrapyramidal side effects.  Caution in liver and renal disease, Parkinson’s, 
CVS disease, epilepsy, depression, prostatic problems.  EPSE – tremor, dystonia (abnormal face and body 
movements), dyskinesia, akathisia and tardive dyskinesia.  Drowsiness, apathy, convulsion, headache, 
confusion, hypotension, tachycardia.  Neuroleptic malignant syndrome – hyperthermia, rigidity, 
autonomic dysfunction.  The atypical antipsychotics are better tolerated and EPSE less frequent.  
 
NICE Guidelines Anti-Psychotics 
 
Established anti-psychotics cost £70 per person per year.  Side effects include shaking, spasms, blurred 
vision, dry mouth, weight gain and fits.  New atypical anti-psychotics as effective with fewer side effects 
but cost £1,220 per person per year.  Theoretically less admissions with atypicals, overall cost cheaper.  
Lack of satisfactory improvement despite sequential use of the recommended doses for 6-8 weeks of at 
least two anti-psychotics, at least one being atypical – then use clozapine at the earliest opportunity.  
Atypicals include amisulpride, olanzapine, quetiapine, risperidone and zotepine.  These drugs should be 
first line in newly diagnosed schizophrenics.  Compliance improved with depot preparations.  
 
Risperidone – similar side effects and hyponatraemia.  Dose 2mg in 1-2 divided doses on first day then 
4mg in 1-2 divided doses on day two – range 4-6mg daily. 
Olanzapine – caution in prostatic problems, paralytic ileus, diabetes mellitus, bone marrow depression.  
Contraindicated in closed angle glaucoma.  Side effects – anti-muscarinic, drowsy, exacerbation of 
Parkinson’s, blood dyscrasias and speech difficulties.  Dose 10mg daily to a maximum of 20mg. 
Quetiapine – similar side effects and prolonged QT interval.  Dose 25mg twice daily on day one; 50mg 
twice dailyon day two; 100mg twice daily on day three; 150mg twice daily on day four then adjust – 
range 300-450mg daily.   
Haloperidol – caution with hypocalcaemia and hypokalaemia.  Fewer anti-muscarinic side effects and 
hypotension, less sedating but EPSE.  Dose initially 1.5-3mg 2-3 times daily or 3-5mg 2-3 times daily in 
severely affected patients.  Elderly half dose.  IM/IV 5-10mg. 
Flupentixol – avoid in porphyria, less sedating, increased EPSE.  Initial dose 3-9mg twice daily to a 
maximum of 18mg daily.  Elderly 25-50% adult dose. 
Chlorpromazine – hypotension and tachycardia.  In schizophrenia oral dose 25mg three times daily to a 
maintenance dose of 75-300mg daily.  30-50% dose in the elderly.  Can be given IM and PR as well. 
Amisulpride – beware Parkinson’s disease.  Insomnia, anxiety, agitation, N&V, constipation, dry mouth.  
Acute attack – 400-800mg daily in two doses, maxm 1.2g daily.  Negative symptoms 50-300mg daily. 
Zotepine – QT prolongation.  Beware epilepsy, acute gout.  Constipation, dyspepsia, dry mouth, 
tachycardia, depression, agitation.  25mg TDS increasing at intervals of four days to a maxm of 100mg 
TDS. 
 
ANTIDEPRESSANTS 
 
NICE Guidelines Depression 
Antidepressants not recommended for initial treatment of mild depression.  Self help and cognitive 
behaviour therapy.  If medication needed SSRI (less side effects).  Two or more depressive episodes, 
significant functional impairment – continue for two years.  Depression and anxiety – treat depression.  
Initial stages of SSRI treatment seek out signs of akathisia, suicidal ideation and increased agitation and 
anxiety.  Continue medication for at least six months.  Agitation – brief period of benzodiazepines.  
Consider switching after 4-6 weeks if no response – different SSRI or mirtazapine; moclobemide, 
reboxetine and lofepramine.  Severe depression consider TCA, venlafaxine.  Serotonin syndrome – 
confusion, delirium, shivering, sweating, myoclonus.  Recent MI or unstable angina start with sertraline. 
 
Treatment of major depression, not usually effective in milder forms of depression.  Major classes of anti-
depressants – tricyclics, selective serotonin re-uptake inhibitors (SSRI’s) and monoamine oxidase 
inhibitors.  First two groups preferred. MAOI’s less effective and react with certain foods.  The SSRI’s 
have less anti-muscarinic side effects – dry mouth, constipation – than tricyclics.  Also lower 
cardiotoxicity in overdosage.  SSRI’s can cause N&V.  Severely ill inpatients tricyclics are more 
effective.  ECT should be considered in severe depression.  Compound preparations of anti-depressants 
and anxiolytics should not be used – anti-depressants are long term and anxiolytics short term.  St. John’s 
wort is used in mild depression but can induce drug metabolising enzymes, beware interactions.  
Hyponatraemia can be associated with all types of anti-depressants – beware convulsions and 
confusion/drowsiness.  Patients should be reviewed every two weeks at the start of treatment.  Continue 
for at least four weeks (6 weeks in elderly) before considering changing medication.  Following remission 
continue for at least 4-6 months (12 months in the elderly).  Combination of two anti-depressants can be 
dangerous.  Withdrawal can present with GIT symptoms, headache, giddiness, insomnia, motor 
restlessness if sudden stoppage after 8 weeks treatment.  Reduce gradually over four weeks.  Can be used 
for panic disorders and phobias. 
Tricyclic and related antidepressant drugs 
Treatment of moderate to severe endogenous depression associated with loss of appetite, sleep 
disturbance.  About two weeks before antidepressant action.  About 10-20% of patients fail to respond to 
tricyclics and inadequate dosage may be the cause.  Low doses initially for the elderly.  Long half-life 
therefore once daily administration, usually at night.  Some antidepressants have sedative effects 
(amitriptyline, clomipramine, dothiepen, doxepin, imipramine).  Agitated and anxious patients benefit 
from these drugs.  All have antimuscarinic and cardiac side effects (doxepin less so).  Side effects include 
arrhythmias and heart block (amitryptiline), convulsions, hepatic and haematological problems.  
Drowsiness, dry mouth, blurred vision, constipation and urinary retention.  Tolerance to side effects can 
occur.  If changing between tricyclics and MAOI’s, a two week gap between the two treatments should 
occur.     
Amitriptyline – depression where sedation is required.  Beware cardiac disease, epilepsy, elderly, hepatic 
problems, thyroid disease, psychosis, glaucoma.  Contraindicated recent myocardial infarction, 
arrhythmias and severe liver disease.  Side effects include dry mouth, sedation, visual disturbance, 
constipation, nausea, CVS problems, behaviour disturbance, dyskinesias, abnormal liver function tests.  
75mg daily in divided doses, elderly 30-75mg,  
Clomipramine – similar problems.  10mg daily increasing to 30-150mg daily as required.  Phobic and 
obsessional states 25mg daily (elderly 10mg) increasing over two weeks to 100-150mg.   
Page 4


Pharmacology Handout – Level Two 
 
DRUGS RELATED TO CENTRAL NERVOUS SYSTEM 
HYPNOTICS AND ANXIOLYTICS 
These will induce sleep at night and sedate during the day.  Dependence (physical and psychological) and 
tolerance occur.  This can account for the difficulty when withdrawing the drug.  Benzodiazepines can 
have a paradoxical effect increasing hostility and aggression – doses need to adjusted up as well as down.  
Barbiturates and alcohol make the situation worse.  Abrupt withdrawal can cause confusion and 
psychosis.  This can develop up to three weeks after stopping benzodiazepines.  Signs – insomnia, 
anxiety, decrease appetite, tremor.  Withdraw by decreasing daily dose by one eighth every two weeks – 
can take months.  Beta blockers may be needed to control symptoms, avoid anti-psychotics.  Before 
prescribing hypnotics try and treat underlying factors causing insomnia.  In short term insomnia a 3 week 
course should not be exceeded.  Chronic insomnia related to anxiety and depression should be addressed 
by treating the underlying condition, use of hypnotics to alleviate symptoms.  Tolerance to hypnotics 
occurs in 3-14 days of continuous use, withdrawal can cause rebound insomnia.  Hypnotics should be 
avoided in the elderly – confusion and ataxia common. 
Benzodiazepines 
Nitrazepam – may have residual effect next day.  Beware respiratory disease, alcohol, elderly, hepatic 
and renal disease.  Drowsiness and light-headedness next day, confusion and ataxia in the elderly and 
amnesia.  5-10mg at bedtime; elderly 2.5-5mg.   
Temazepam – shorter acting with little hangover effect.  Equivalent dose 10mg = 5mg nitrazepam.  10-
20mg at bedtime, exceptionally 30-40mg.  Elderly 10mg bedtime. 
Others 
Zolpidem – acts at the same receptors but is not a benzodiazepine.  Short duration, no hangover.  Not 
licensed for long term use.  Beware depression, respiratory disease, alcohol, elderly, hepatic and renal 
disease.  Can cause diarrhoea, N&V, headache, drowsiness, dependence, nightmares, double vision, 
tremor.  10mg bedtime, elderly 5mg.       
Zopiclone – similar to zolpidem with dry mouth, metallic taste.  7.5mg bedtime, elderly 3.75mg. 
Chloral Hydrate – same cautions, can cause gastric irritation and eosinophilia as well.  500-1000mg 
with plenty of water at bedtime.  Child 30-50mg/kgm, maxm 1000mg.   
 
KEY POINTS – HYPNOTICS 
1. Give 30 minutes before going to bed (zolpidem is taken immediately before retiring – fast onset) 
2. Low initial dose especially in the elderly 
3. Limit treatment to 2-3 weeks, preferably alternate nights 
4. If dependence, withdraw slowly to avoid symptoms of withdrawal 
5. Onset of drug-induced sleep may be followed by a deterioration of patient’s condition  
  
ANXIOLYTICS 
Treatment of stress related symptoms.  Not appropriate for depression and chronic psychosis.  In 
bereavement psychological adjustment may be inhibited by benzodiazepines.  Lowest possible dose for 
shortest possible time.  Dependence likely in alcoholics, drug abuse and personality disorders.   
Benzodiazepines 
Short term relief of severe anxiety.  Diazepam has sustained action and lorazepam is shorter acting.  
Lorazepam has been used in panic disorders and control of panic attacks.   
Diazepam – used in short term anxiety, alcohol withdrawal, status epilepticus, febrile convulsions, 
muscle spasms.  Beware respiratory disease, muscle disorders (relaxant effect), alcohol abuse, personality 
disorders.  Drowsiness and light-headedness next day, confusion and ataxia, amnesia, dependence, 
paradoxical aggression, muscle weakness, GIT and visual disturbance and tremor.  2mg TDS orally, 
increasing to 15-30mg daily.  Elderly, half adult dose.  Suppository 10-30mg.  IV 5mg/minute into a large 
vein up to 10mg, repeat in 4 hours.   
Lorazepam – similar problems.  1-4mg daily in divided doses.  Elderly half adult dose.  IV 25-30mcg/kg 
repeated every 6 hours into large vein. 
 
KEY POINTS – BENZODIAZEPINES 
1. Normally for short term treatment only 
2. Drowsiness is a side effect – warn car drivers 
3. Alcohol may have additive effects and should be avoided 
4. Withdrawal of treatment should be slow 
  
ANTIPSYCHOTICS 
These drugs are also known as neuroleptics and major tranquillisers.  In the short term these drugs are 
used to quieten disturbed patients whatever the underlying psychopathology.  In schizophrenia these 
drugs relieve the florid psychotic symptoms such as hallucinations and delusions.  Less useful in 
withdrawn apathetic patients.  Long term treatment may be necessary.  Work by blocking D
2
 receptors 
and may therefore produce extrapyramidal side effects.  Caution in liver and renal disease, Parkinson’s, 
CVS disease, epilepsy, depression, prostatic problems.  EPSE – tremor, dystonia (abnormal face and body 
movements), dyskinesia, akathisia and tardive dyskinesia.  Drowsiness, apathy, convulsion, headache, 
confusion, hypotension, tachycardia.  Neuroleptic malignant syndrome – hyperthermia, rigidity, 
autonomic dysfunction.  The atypical antipsychotics are better tolerated and EPSE less frequent.  
 
NICE Guidelines Anti-Psychotics 
 
Established anti-psychotics cost £70 per person per year.  Side effects include shaking, spasms, blurred 
vision, dry mouth, weight gain and fits.  New atypical anti-psychotics as effective with fewer side effects 
but cost £1,220 per person per year.  Theoretically less admissions with atypicals, overall cost cheaper.  
Lack of satisfactory improvement despite sequential use of the recommended doses for 6-8 weeks of at 
least two anti-psychotics, at least one being atypical – then use clozapine at the earliest opportunity.  
Atypicals include amisulpride, olanzapine, quetiapine, risperidone and zotepine.  These drugs should be 
first line in newly diagnosed schizophrenics.  Compliance improved with depot preparations.  
 
Risperidone – similar side effects and hyponatraemia.  Dose 2mg in 1-2 divided doses on first day then 
4mg in 1-2 divided doses on day two – range 4-6mg daily. 
Olanzapine – caution in prostatic problems, paralytic ileus, diabetes mellitus, bone marrow depression.  
Contraindicated in closed angle glaucoma.  Side effects – anti-muscarinic, drowsy, exacerbation of 
Parkinson’s, blood dyscrasias and speech difficulties.  Dose 10mg daily to a maximum of 20mg. 
Quetiapine – similar side effects and prolonged QT interval.  Dose 25mg twice daily on day one; 50mg 
twice dailyon day two; 100mg twice daily on day three; 150mg twice daily on day four then adjust – 
range 300-450mg daily.   
Haloperidol – caution with hypocalcaemia and hypokalaemia.  Fewer anti-muscarinic side effects and 
hypotension, less sedating but EPSE.  Dose initially 1.5-3mg 2-3 times daily or 3-5mg 2-3 times daily in 
severely affected patients.  Elderly half dose.  IM/IV 5-10mg. 
Flupentixol – avoid in porphyria, less sedating, increased EPSE.  Initial dose 3-9mg twice daily to a 
maximum of 18mg daily.  Elderly 25-50% adult dose. 
Chlorpromazine – hypotension and tachycardia.  In schizophrenia oral dose 25mg three times daily to a 
maintenance dose of 75-300mg daily.  30-50% dose in the elderly.  Can be given IM and PR as well. 
Amisulpride – beware Parkinson’s disease.  Insomnia, anxiety, agitation, N&V, constipation, dry mouth.  
Acute attack – 400-800mg daily in two doses, maxm 1.2g daily.  Negative symptoms 50-300mg daily. 
Zotepine – QT prolongation.  Beware epilepsy, acute gout.  Constipation, dyspepsia, dry mouth, 
tachycardia, depression, agitation.  25mg TDS increasing at intervals of four days to a maxm of 100mg 
TDS. 
 
ANTIDEPRESSANTS 
 
NICE Guidelines Depression 
Antidepressants not recommended for initial treatment of mild depression.  Self help and cognitive 
behaviour therapy.  If medication needed SSRI (less side effects).  Two or more depressive episodes, 
significant functional impairment – continue for two years.  Depression and anxiety – treat depression.  
Initial stages of SSRI treatment seek out signs of akathisia, suicidal ideation and increased agitation and 
anxiety.  Continue medication for at least six months.  Agitation – brief period of benzodiazepines.  
Consider switching after 4-6 weeks if no response – different SSRI or mirtazapine; moclobemide, 
reboxetine and lofepramine.  Severe depression consider TCA, venlafaxine.  Serotonin syndrome – 
confusion, delirium, shivering, sweating, myoclonus.  Recent MI or unstable angina start with sertraline. 
 
Treatment of major depression, not usually effective in milder forms of depression.  Major classes of anti-
depressants – tricyclics, selective serotonin re-uptake inhibitors (SSRI’s) and monoamine oxidase 
inhibitors.  First two groups preferred. MAOI’s less effective and react with certain foods.  The SSRI’s 
have less anti-muscarinic side effects – dry mouth, constipation – than tricyclics.  Also lower 
cardiotoxicity in overdosage.  SSRI’s can cause N&V.  Severely ill inpatients tricyclics are more 
effective.  ECT should be considered in severe depression.  Compound preparations of anti-depressants 
and anxiolytics should not be used – anti-depressants are long term and anxiolytics short term.  St. John’s 
wort is used in mild depression but can induce drug metabolising enzymes, beware interactions.  
Hyponatraemia can be associated with all types of anti-depressants – beware convulsions and 
confusion/drowsiness.  Patients should be reviewed every two weeks at the start of treatment.  Continue 
for at least four weeks (6 weeks in elderly) before considering changing medication.  Following remission 
continue for at least 4-6 months (12 months in the elderly).  Combination of two anti-depressants can be 
dangerous.  Withdrawal can present with GIT symptoms, headache, giddiness, insomnia, motor 
restlessness if sudden stoppage after 8 weeks treatment.  Reduce gradually over four weeks.  Can be used 
for panic disorders and phobias. 
Tricyclic and related antidepressant drugs 
Treatment of moderate to severe endogenous depression associated with loss of appetite, sleep 
disturbance.  About two weeks before antidepressant action.  About 10-20% of patients fail to respond to 
tricyclics and inadequate dosage may be the cause.  Low doses initially for the elderly.  Long half-life 
therefore once daily administration, usually at night.  Some antidepressants have sedative effects 
(amitriptyline, clomipramine, dothiepen, doxepin, imipramine).  Agitated and anxious patients benefit 
from these drugs.  All have antimuscarinic and cardiac side effects (doxepin less so).  Side effects include 
arrhythmias and heart block (amitryptiline), convulsions, hepatic and haematological problems.  
Drowsiness, dry mouth, blurred vision, constipation and urinary retention.  Tolerance to side effects can 
occur.  If changing between tricyclics and MAOI’s, a two week gap between the two treatments should 
occur.     
Amitriptyline – depression where sedation is required.  Beware cardiac disease, epilepsy, elderly, hepatic 
problems, thyroid disease, psychosis, glaucoma.  Contraindicated recent myocardial infarction, 
arrhythmias and severe liver disease.  Side effects include dry mouth, sedation, visual disturbance, 
constipation, nausea, CVS problems, behaviour disturbance, dyskinesias, abnormal liver function tests.  
75mg daily in divided doses, elderly 30-75mg,  
Clomipramine – similar problems.  10mg daily increasing to 30-150mg daily as required.  Phobic and 
obsessional states 25mg daily (elderly 10mg) increasing over two weeks to 100-150mg.   
Dothiepen – similar problems.  75mg daily (elderly 50-75mg) up to 150mg.   
Doxepin – similar problems.  75mg daily up to 300mg in three divided doses.  Elderly 10-50mg daily. 
Imipramine – similar problems.  75mg daily up to 150-200mg in divided doses.  Elderly 10mg daily 
increasing to 30-50mg.   
 
KEY POINTS – ANTI-DEPRESSANTS 
1. Onset of action is slow, 2-4 weeks 
2. Encourage patients to persist with treatment 
3. Maintain dose level for at least one month after improvement before lowering the dose 
4. Drug withdrawal should be carried out slowly 
5. Combined treatment with MAOI’s is contraindicated, leave two weeks before starting MAOI’s  
 
Monoamine Oxidase-Inhibitors (MAOI’s) 
Used less frequently because of food interactions.  Can be used in patients where tricyclics are 
unsuccessful.  Tranylcypromine more stimulant than phenelzine and isocarboxazid.  Phobic, 
hypochondriacal or hysterical patients respond best to MAOI’s.  Cause an increase in amine 
neurotransmitters.  It also blocks metabolism of sympathomimetics so that pressor action may be 
potentiated.  Pressor effect of tyramine (found in cheese, oxo, Bovril, pickled herring, yeast extract) may 
also be dangerous.  Danger present up to two weeks after stopping the drug.  Do not start other 
antidepressants until two weeks has elapsed after stopping MAOI’s.  The same applies if starting MAOI’s 
after tricyclics.    
Phenelzine – beware diabetes, CVS disease, epilepsy, elderly.  Contraindicated in liver disease, 
cerebrovascular disease, phaeochromocytoma.  Side effects include postural hypotension, dizziness, 
insomnia, headache, GIT disturbance, elevated liver enzymes, weight gain.  15mg TDS, QDS after 2 
weeks.  Maxm 30mg TDS.  Reduce to lowest possible maintenance dose – 15mg alternate days.   
Isocarboxazid – similar problems.  30mg daily increasing to a maxm of 60mg after four weeks, reducing 
to 10-20mg.  Elderly half dose.   
Tranylcypromine – similar problems.  Insomnia if given in the evening.  10mg BD not later than 
15.00hrs increasing the second dose to 20mg after seven days. 
Moclobemide – major depression and social phobia.  Reversible inhibition of monoamine oxidase type 
A, used as second line treatment.  Less pressor effect but avoidance of tyramine rich foods still advised.  
Should not be given with other antidepressants.  Avoid in excited/agitated patients.  Sleep disturbance, 
dizziness and GIT disturbance – similar problems to other MAOI’s.  300mg daily increasing on the 4
th
 
day to 600mg daily in two divided doses for 8-12 weeks to assess efficacy.   
 
KEY POINTS – MONOAMINE OXIDASE INHIBITORS 
1. Potentiate the actions of many pressor drugs  
2. Throbbing headache may be warning symptom of a rise in blood pressure 
3. Combined treatment with other anti-depressants is contraindicated 
4. At least 2 weeks must elapse between MAOI therapy and other treatment 
5. Warn patients not to eat cheese, broad beans, pickled herring, meat or yeast extract  
 
Selective serotonin re-uptake inhibitors 
Inhibit re-uptake of serotonin (5HT).  Care in patients with epilepsy, mania, CVS disease, diabetes, liver 
and renal impairment.  Avoid abrupt withdrawal.  Less sedating, fewer anti-muscarinic side effects.  
N&V, anorexia, urticaria and arthralgia.  Dyskinesia and hyponatraemia.   
Fluoxetine – can alter blood sugar, fever, abnormal bleeding, CVA.  20mg daily. 
Paroxetine -  may worsen panic attack symptoms initially.  Extrapyramidal side effects.  Can be used in 
post-traumatic stress disorder - 20mg each morning, increasing in weekly increments of 10mg – maxm 
Page 5


Pharmacology Handout – Level Two 
 
DRUGS RELATED TO CENTRAL NERVOUS SYSTEM 
HYPNOTICS AND ANXIOLYTICS 
These will induce sleep at night and sedate during the day.  Dependence (physical and psychological) and 
tolerance occur.  This can account for the difficulty when withdrawing the drug.  Benzodiazepines can 
have a paradoxical effect increasing hostility and aggression – doses need to adjusted up as well as down.  
Barbiturates and alcohol make the situation worse.  Abrupt withdrawal can cause confusion and 
psychosis.  This can develop up to three weeks after stopping benzodiazepines.  Signs – insomnia, 
anxiety, decrease appetite, tremor.  Withdraw by decreasing daily dose by one eighth every two weeks – 
can take months.  Beta blockers may be needed to control symptoms, avoid anti-psychotics.  Before 
prescribing hypnotics try and treat underlying factors causing insomnia.  In short term insomnia a 3 week 
course should not be exceeded.  Chronic insomnia related to anxiety and depression should be addressed 
by treating the underlying condition, use of hypnotics to alleviate symptoms.  Tolerance to hypnotics 
occurs in 3-14 days of continuous use, withdrawal can cause rebound insomnia.  Hypnotics should be 
avoided in the elderly – confusion and ataxia common. 
Benzodiazepines 
Nitrazepam – may have residual effect next day.  Beware respiratory disease, alcohol, elderly, hepatic 
and renal disease.  Drowsiness and light-headedness next day, confusion and ataxia in the elderly and 
amnesia.  5-10mg at bedtime; elderly 2.5-5mg.   
Temazepam – shorter acting with little hangover effect.  Equivalent dose 10mg = 5mg nitrazepam.  10-
20mg at bedtime, exceptionally 30-40mg.  Elderly 10mg bedtime. 
Others 
Zolpidem – acts at the same receptors but is not a benzodiazepine.  Short duration, no hangover.  Not 
licensed for long term use.  Beware depression, respiratory disease, alcohol, elderly, hepatic and renal 
disease.  Can cause diarrhoea, N&V, headache, drowsiness, dependence, nightmares, double vision, 
tremor.  10mg bedtime, elderly 5mg.       
Zopiclone – similar to zolpidem with dry mouth, metallic taste.  7.5mg bedtime, elderly 3.75mg. 
Chloral Hydrate – same cautions, can cause gastric irritation and eosinophilia as well.  500-1000mg 
with plenty of water at bedtime.  Child 30-50mg/kgm, maxm 1000mg.   
 
KEY POINTS – HYPNOTICS 
1. Give 30 minutes before going to bed (zolpidem is taken immediately before retiring – fast onset) 
2. Low initial dose especially in the elderly 
3. Limit treatment to 2-3 weeks, preferably alternate nights 
4. If dependence, withdraw slowly to avoid symptoms of withdrawal 
5. Onset of drug-induced sleep may be followed by a deterioration of patient’s condition  
  
ANXIOLYTICS 
Treatment of stress related symptoms.  Not appropriate for depression and chronic psychosis.  In 
bereavement psychological adjustment may be inhibited by benzodiazepines.  Lowest possible dose for 
shortest possible time.  Dependence likely in alcoholics, drug abuse and personality disorders.   
Benzodiazepines 
Short term relief of severe anxiety.  Diazepam has sustained action and lorazepam is shorter acting.  
Lorazepam has been used in panic disorders and control of panic attacks.   
Diazepam – used in short term anxiety, alcohol withdrawal, status epilepticus, febrile convulsions, 
muscle spasms.  Beware respiratory disease, muscle disorders (relaxant effect), alcohol abuse, personality 
disorders.  Drowsiness and light-headedness next day, confusion and ataxia, amnesia, dependence, 
paradoxical aggression, muscle weakness, GIT and visual disturbance and tremor.  2mg TDS orally, 
increasing to 15-30mg daily.  Elderly, half adult dose.  Suppository 10-30mg.  IV 5mg/minute into a large 
vein up to 10mg, repeat in 4 hours.   
Lorazepam – similar problems.  1-4mg daily in divided doses.  Elderly half adult dose.  IV 25-30mcg/kg 
repeated every 6 hours into large vein. 
 
KEY POINTS – BENZODIAZEPINES 
1. Normally for short term treatment only 
2. Drowsiness is a side effect – warn car drivers 
3. Alcohol may have additive effects and should be avoided 
4. Withdrawal of treatment should be slow 
  
ANTIPSYCHOTICS 
These drugs are also known as neuroleptics and major tranquillisers.  In the short term these drugs are 
used to quieten disturbed patients whatever the underlying psychopathology.  In schizophrenia these 
drugs relieve the florid psychotic symptoms such as hallucinations and delusions.  Less useful in 
withdrawn apathetic patients.  Long term treatment may be necessary.  Work by blocking D
2
 receptors 
and may therefore produce extrapyramidal side effects.  Caution in liver and renal disease, Parkinson’s, 
CVS disease, epilepsy, depression, prostatic problems.  EPSE – tremor, dystonia (abnormal face and body 
movements), dyskinesia, akathisia and tardive dyskinesia.  Drowsiness, apathy, convulsion, headache, 
confusion, hypotension, tachycardia.  Neuroleptic malignant syndrome – hyperthermia, rigidity, 
autonomic dysfunction.  The atypical antipsychotics are better tolerated and EPSE less frequent.  
 
NICE Guidelines Anti-Psychotics 
 
Established anti-psychotics cost £70 per person per year.  Side effects include shaking, spasms, blurred 
vision, dry mouth, weight gain and fits.  New atypical anti-psychotics as effective with fewer side effects 
but cost £1,220 per person per year.  Theoretically less admissions with atypicals, overall cost cheaper.  
Lack of satisfactory improvement despite sequential use of the recommended doses for 6-8 weeks of at 
least two anti-psychotics, at least one being atypical – then use clozapine at the earliest opportunity.  
Atypicals include amisulpride, olanzapine, quetiapine, risperidone and zotepine.  These drugs should be 
first line in newly diagnosed schizophrenics.  Compliance improved with depot preparations.  
 
Risperidone – similar side effects and hyponatraemia.  Dose 2mg in 1-2 divided doses on first day then 
4mg in 1-2 divided doses on day two – range 4-6mg daily. 
Olanzapine – caution in prostatic problems, paralytic ileus, diabetes mellitus, bone marrow depression.  
Contraindicated in closed angle glaucoma.  Side effects – anti-muscarinic, drowsy, exacerbation of 
Parkinson’s, blood dyscrasias and speech difficulties.  Dose 10mg daily to a maximum of 20mg. 
Quetiapine – similar side effects and prolonged QT interval.  Dose 25mg twice daily on day one; 50mg 
twice dailyon day two; 100mg twice daily on day three; 150mg twice daily on day four then adjust – 
range 300-450mg daily.   
Haloperidol – caution with hypocalcaemia and hypokalaemia.  Fewer anti-muscarinic side effects and 
hypotension, less sedating but EPSE.  Dose initially 1.5-3mg 2-3 times daily or 3-5mg 2-3 times daily in 
severely affected patients.  Elderly half dose.  IM/IV 5-10mg. 
Flupentixol – avoid in porphyria, less sedating, increased EPSE.  Initial dose 3-9mg twice daily to a 
maximum of 18mg daily.  Elderly 25-50% adult dose. 
Chlorpromazine – hypotension and tachycardia.  In schizophrenia oral dose 25mg three times daily to a 
maintenance dose of 75-300mg daily.  30-50% dose in the elderly.  Can be given IM and PR as well. 
Amisulpride – beware Parkinson’s disease.  Insomnia, anxiety, agitation, N&V, constipation, dry mouth.  
Acute attack – 400-800mg daily in two doses, maxm 1.2g daily.  Negative symptoms 50-300mg daily. 
Zotepine – QT prolongation.  Beware epilepsy, acute gout.  Constipation, dyspepsia, dry mouth, 
tachycardia, depression, agitation.  25mg TDS increasing at intervals of four days to a maxm of 100mg 
TDS. 
 
ANTIDEPRESSANTS 
 
NICE Guidelines Depression 
Antidepressants not recommended for initial treatment of mild depression.  Self help and cognitive 
behaviour therapy.  If medication needed SSRI (less side effects).  Two or more depressive episodes, 
significant functional impairment – continue for two years.  Depression and anxiety – treat depression.  
Initial stages of SSRI treatment seek out signs of akathisia, suicidal ideation and increased agitation and 
anxiety.  Continue medication for at least six months.  Agitation – brief period of benzodiazepines.  
Consider switching after 4-6 weeks if no response – different SSRI or mirtazapine; moclobemide, 
reboxetine and lofepramine.  Severe depression consider TCA, venlafaxine.  Serotonin syndrome – 
confusion, delirium, shivering, sweating, myoclonus.  Recent MI or unstable angina start with sertraline. 
 
Treatment of major depression, not usually effective in milder forms of depression.  Major classes of anti-
depressants – tricyclics, selective serotonin re-uptake inhibitors (SSRI’s) and monoamine oxidase 
inhibitors.  First two groups preferred. MAOI’s less effective and react with certain foods.  The SSRI’s 
have less anti-muscarinic side effects – dry mouth, constipation – than tricyclics.  Also lower 
cardiotoxicity in overdosage.  SSRI’s can cause N&V.  Severely ill inpatients tricyclics are more 
effective.  ECT should be considered in severe depression.  Compound preparations of anti-depressants 
and anxiolytics should not be used – anti-depressants are long term and anxiolytics short term.  St. John’s 
wort is used in mild depression but can induce drug metabolising enzymes, beware interactions.  
Hyponatraemia can be associated with all types of anti-depressants – beware convulsions and 
confusion/drowsiness.  Patients should be reviewed every two weeks at the start of treatment.  Continue 
for at least four weeks (6 weeks in elderly) before considering changing medication.  Following remission 
continue for at least 4-6 months (12 months in the elderly).  Combination of two anti-depressants can be 
dangerous.  Withdrawal can present with GIT symptoms, headache, giddiness, insomnia, motor 
restlessness if sudden stoppage after 8 weeks treatment.  Reduce gradually over four weeks.  Can be used 
for panic disorders and phobias. 
Tricyclic and related antidepressant drugs 
Treatment of moderate to severe endogenous depression associated with loss of appetite, sleep 
disturbance.  About two weeks before antidepressant action.  About 10-20% of patients fail to respond to 
tricyclics and inadequate dosage may be the cause.  Low doses initially for the elderly.  Long half-life 
therefore once daily administration, usually at night.  Some antidepressants have sedative effects 
(amitriptyline, clomipramine, dothiepen, doxepin, imipramine).  Agitated and anxious patients benefit 
from these drugs.  All have antimuscarinic and cardiac side effects (doxepin less so).  Side effects include 
arrhythmias and heart block (amitryptiline), convulsions, hepatic and haematological problems.  
Drowsiness, dry mouth, blurred vision, constipation and urinary retention.  Tolerance to side effects can 
occur.  If changing between tricyclics and MAOI’s, a two week gap between the two treatments should 
occur.     
Amitriptyline – depression where sedation is required.  Beware cardiac disease, epilepsy, elderly, hepatic 
problems, thyroid disease, psychosis, glaucoma.  Contraindicated recent myocardial infarction, 
arrhythmias and severe liver disease.  Side effects include dry mouth, sedation, visual disturbance, 
constipation, nausea, CVS problems, behaviour disturbance, dyskinesias, abnormal liver function tests.  
75mg daily in divided doses, elderly 30-75mg,  
Clomipramine – similar problems.  10mg daily increasing to 30-150mg daily as required.  Phobic and 
obsessional states 25mg daily (elderly 10mg) increasing over two weeks to 100-150mg.   
Dothiepen – similar problems.  75mg daily (elderly 50-75mg) up to 150mg.   
Doxepin – similar problems.  75mg daily up to 300mg in three divided doses.  Elderly 10-50mg daily. 
Imipramine – similar problems.  75mg daily up to 150-200mg in divided doses.  Elderly 10mg daily 
increasing to 30-50mg.   
 
KEY POINTS – ANTI-DEPRESSANTS 
1. Onset of action is slow, 2-4 weeks 
2. Encourage patients to persist with treatment 
3. Maintain dose level for at least one month after improvement before lowering the dose 
4. Drug withdrawal should be carried out slowly 
5. Combined treatment with MAOI’s is contraindicated, leave two weeks before starting MAOI’s  
 
Monoamine Oxidase-Inhibitors (MAOI’s) 
Used less frequently because of food interactions.  Can be used in patients where tricyclics are 
unsuccessful.  Tranylcypromine more stimulant than phenelzine and isocarboxazid.  Phobic, 
hypochondriacal or hysterical patients respond best to MAOI’s.  Cause an increase in amine 
neurotransmitters.  It also blocks metabolism of sympathomimetics so that pressor action may be 
potentiated.  Pressor effect of tyramine (found in cheese, oxo, Bovril, pickled herring, yeast extract) may 
also be dangerous.  Danger present up to two weeks after stopping the drug.  Do not start other 
antidepressants until two weeks has elapsed after stopping MAOI’s.  The same applies if starting MAOI’s 
after tricyclics.    
Phenelzine – beware diabetes, CVS disease, epilepsy, elderly.  Contraindicated in liver disease, 
cerebrovascular disease, phaeochromocytoma.  Side effects include postural hypotension, dizziness, 
insomnia, headache, GIT disturbance, elevated liver enzymes, weight gain.  15mg TDS, QDS after 2 
weeks.  Maxm 30mg TDS.  Reduce to lowest possible maintenance dose – 15mg alternate days.   
Isocarboxazid – similar problems.  30mg daily increasing to a maxm of 60mg after four weeks, reducing 
to 10-20mg.  Elderly half dose.   
Tranylcypromine – similar problems.  Insomnia if given in the evening.  10mg BD not later than 
15.00hrs increasing the second dose to 20mg after seven days. 
Moclobemide – major depression and social phobia.  Reversible inhibition of monoamine oxidase type 
A, used as second line treatment.  Less pressor effect but avoidance of tyramine rich foods still advised.  
Should not be given with other antidepressants.  Avoid in excited/agitated patients.  Sleep disturbance, 
dizziness and GIT disturbance – similar problems to other MAOI’s.  300mg daily increasing on the 4
th
 
day to 600mg daily in two divided doses for 8-12 weeks to assess efficacy.   
 
KEY POINTS – MONOAMINE OXIDASE INHIBITORS 
1. Potentiate the actions of many pressor drugs  
2. Throbbing headache may be warning symptom of a rise in blood pressure 
3. Combined treatment with other anti-depressants is contraindicated 
4. At least 2 weeks must elapse between MAOI therapy and other treatment 
5. Warn patients not to eat cheese, broad beans, pickled herring, meat or yeast extract  
 
Selective serotonin re-uptake inhibitors 
Inhibit re-uptake of serotonin (5HT).  Care in patients with epilepsy, mania, CVS disease, diabetes, liver 
and renal impairment.  Avoid abrupt withdrawal.  Less sedating, fewer anti-muscarinic side effects.  
N&V, anorexia, urticaria and arthralgia.  Dyskinesia and hyponatraemia.   
Fluoxetine – can alter blood sugar, fever, abnormal bleeding, CVA.  20mg daily. 
Paroxetine -  may worsen panic attack symptoms initially.  Extrapyramidal side effects.  Can be used in 
post-traumatic stress disorder - 20mg each morning, increasing in weekly increments of 10mg – maxm 
50mg daily.  Obsessive compulsive 20mg to a maxm of 60mg daily.  Panic disorder 10mg each morning 
to a maxm of 50mg.     
Sertraline – similar problems.  Tachycardia, amnesia, aggression, liver and pancreas disorder, 
thrombocytopaenia.  Depression 50mg daily, increments of 50mg over several weeks to a maxm of 
200mg daily.  Obsessive compulsive similar dose.     
 
KEY POINTS – SELECTIVE SEROTONIN RE-UPTAKE INHIBITORS 
1. Less sedative than tricyclic anti-depressants 
2. GIT side effects are dose related 
3. Do not cause weight gain 
4. Caution necessary in epilepsy 
5. A gap of 2-5 weeks must elapse between SSRI and MAOI therapy  
 
ANTI-EMETICS 
Effective treatment for motion sickness is hyoscine – drowsy, anti-muscarinic side effects.  
Antihistamines less effective, similar side effects.  Metoclopramide and phenothiazines act selectively on 
chemoreceptor trigger zone (CTZ) and are ineffective in motion sickness.  Severe vomiting in pregnancy 
may require phenothiazines which are dopamine anatagonists.  They act centrally by blocking the CTZ.  
Prophylaxis and treatment of N&V associated with neoplastic disease, radiation sickness, narcotic emesis.  
Metoclopramide also has an effect on the gut.  It may induce acute dystonic reactions including 
oculogyric crises.  Injection of procyclidine will abort attack.  Domperidone is used in cytotoxic induced 
N&V.  Less sedation and dytonia and acts on CTZ.  Specific 5HT3 serotonin antagonists (granisetron, 
ondansetron) used in N&V induced by cytotoxics.      
Anti-histamines 
Cyclizine – N&V, vertigo and motion sickness.  Caution severe heart failure.  Caution in hepatic and 
renal impairment.  Less sedating, dry mouth and blurred vision.  50mg TDS, child 6-12 years 25mg TDS.  
IM or IV.   
Phenothiazines 
Prochlorperazine – severe N&V, vertigo.  Beware hypotension.  Can cause extrapyramidal side effects.  
20mg orally followed by 10mg TDS, deep IM 12.5mg.  Suppository 25mg.   
Others  
Metoclopramide – N&V in GIT disturbance.  Caution in hepatic and renal impairment, elderly, 
epileptics.  Contraindicated in GIT obstruction and post-bowel surgery.  Side effects include 
extrapyramidal effects, drowsiness, depression, pruritis.  IV over 1-2 mins 10mg – do not exceed 
500mcg/kg daily.        
Domperidone – not recommended for prophylaxis.  Can raise prolactin levels.  Acute N&V 10-20mg 
every 4-8 hours, suppository 30-60mg every 4-8 hours. 
5HT
3
 antagonists 
Granisetron – side effects include constipation, headache, rash, increased liver enzymes.  1-2mg orally 
before cytotoxic therapy, then 1mg BD.  IV 3mg before treatment, maxm 9mg in 24 hours.  Post-
operative N&V, dilute to 5mls and give over 30 seconds; 1mg for prevention.   
Ondansetron – can cause constipation, headache, hiccups, visual disturbance, increased liver enzymes, 
involuntary movements.  Oral 8mg 1-2 hours pre-treatment, PR 16mg 1-2 hours pre-treatment, IV 8mg 
before treatment.  8mg every 12 hours for up to 5 days.  Prevention of post-operative N&V 4mg IV at 
induction.  Same for treatment of post-operative N&V. 
 
KEY POINTS – ANTI-EMETICS 
1. Hyoscine and antihistamines are useful in motion sickness 
2. Some phenothiazines are effective in more severe vomiting 
3. Domperidone is effective in nausea and vomiting secondary to disease and cytotoxic therapy 
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