Test: General Pharmacology - 8 - NEET PG MCQ

Orphan drugs refer to medications utilised for treating uncommon illnesses. For instance:

• N-acetylcysteine for paracetamol toxicity.
• Other examples are fomepizole, sodium nitrite, and digibind.

Efficacy refers to the highest level of effect that a medication can achieve, independent of the dosage. This is assessed in a controlled environment during clinical trials.

Effectiveness, on the other hand, describes how a drug performs in a practical clinical setting. It may not necessarily provide the utmost advantage.

GCP guidelines are established to protect the welfare of participants in clinical trials. These guidelines must be followed throughout all stages of clinical research.

Preclinical trials, conducted on animals, are governed by separate regulations set forth by CPCSEA (Committee for the Purpose of Control and Supervision of Experiments on Animals).

The placebo has a crucial function in clinical trials. To determine whether the effect is due to a medication or merely coincidental, a dummy treatment called a placebo is administered to the control group. The placebo might have an effect on a participant, or it might not.

Orphan drugs are utilised for uncommon diseases. For example:

• Erythropoietin is used for treating anaemia in individuals with chronic renal failure.

Phase I is conducted in healthy participants, while subsequent phases take place in patients.

• Phase II involves a limited group of patients.
• Phase III is a multicentre trial that necessitates a large number of patients.
• Phase IV is a post-marketing study carried out for each drug.

Its purpose is to identify any rare adverse effects.

Among the options presented, the most suitable choice appears to be propylthiouracil. However, it is important to note that this medication can lead to hepatotoxicity in the mother.

Thalidomide is a highly teratogenic medication that may lead to phocomelia as a congenital defect.

Methotrexate, warfarin, and tetracycline are not recommended during pregnancy.

Penicillins are excreted by renal tubules. Probenecid competitively obstructs the secretion of penicillins and is utilised to enhance the efficacy of these antibiotics.

Baroreceptor sensitivity decreases in older individuals. Factors such as total body water, lean body mass, and body fat diminish in elderly patients, resulting in a reduced volume of distribution. Additionally:

• Renal function declines in older patients.
• For some medications, hepatic metabolism is also diminished.
• Baroreceptor and other reflexes are less responsive in the elderly compared to younger individuals.

It is important to note that while receptor sensitivity to medications—especially central nervous system drugs—tends to increase, baroreceptor sensitivity is diminished in older adults.

Teratogenicity refers to the formation of a distinct set of malformations resulting from the use of a medication during pregnancy.

• Various drugs target specific stages of fetal development.
• The likelihood of teratogenesis is dependent on the dosage.
• Heparin is unable to cross the placenta, making it safe for use during pregnancy.