Pharmacology Antimicrobial and Chemotherapeutic Agents 3

Question 1

A patient taking isoniazid (INH) for tuberculosis develops peripheral neuropathy. This adverse effect is best prevented by supplementing with:

Accepted Answer

Pyridoxine (Vitamin B6)

Answer

INH inhibits pyridoxal phosphate synthesis and competes with pyridoxine, causing peripheral neuropathy that is prevented by concurrent pyridoxine supplementation.

Question 2

Which antibiotic class is contraindicated in children under 8 years of age due to risk of permanent tooth discoloration?

Accepted Answer

Tetracyclines

Answer

Tetracyclines bind to calcium in developing teeth and bones, causing permanent yellow-gray-brown discoloration and enamel hypoplasia in children under 8.

Question 3

Trimethoprim-sulfamethoxazole (TMP-SMX) inhibits bacterial folate synthesis by blocking which two sequential steps?

Accepted Answer

Dihydropteroate synthase and dihydrofolate reductase

Answer

Sulfamethoxazole inhibits dihydropteroate synthase while trimethoprim inhibits dihydrofolate reductase; together they create sequential blockade of folate synthesis.

Question 4

Which antiviral drug is used as prophylaxis and treatment for influenza A and B and works by inhibiting neuraminidase?

Accepted Answer

Oseltamivir

Answer

Oseltamivir (Tamiflu) inhibits viral neuraminidase, preventing release of new virions from infected cells and limiting spread of influenza A and B.

Question 5

A patient develops gray baby syndrome after receiving which antibiotic?

Accepted Answer

Chloramphenicol

Answer

Chloramphenicol causes gray baby syndrome in neonates because their immature hepatic glucuronyl transferase cannot metabolize the drug, leading to toxic accumulation.

Pharmacology Practice Test

Pharmacology Practice Test

Pharmacology Antimicrobial and Chemotherapeutic Agents 3