Which of the following drugs act by inhibiting folate synthesis in bacteria and * it is advisable to drink 8 ounces of water during this drug's use because it may cause crystalluria and subsequent kidney stone formation.

Correct Answer: C

Rationale: Rationale: 1. Correct Answer (C - Sulfonamides): Sulfonamides inhibit folate synthesis in bacteria. Drinking water helps prevent crystalluria and kidney stone formation. 2. Incorrect Choices: A. Vancomycin - Acts on cell wall synthesis, not folate synthesis. B. Linezolid - Inhibits protein synthesis, not folate synthesis. D. Penicillin - Inhibits cell wall synthesis, not folate synthesis.

Correct Answer: B

Rationale: The correct answer is B: Meningeal tuberculosis. Corticosteroids are contraindicated in meningeal tuberculosis because they can suppress the immune response, leading to increased bacterial growth and dissemination in the central nervous system. For miliary, intestinal, and renal tuberculosis, corticosteroids can be beneficial in reducing inflammation and improving outcomes.

Correct Answer: C

Rationale: The correct answer is C: Valacyclovir. Valacyclovir is an antiviral medication commonly used to treat herpes simplex virus infections. It is a prodrug of acyclovir, which inhibits viral DNA replication. Zanamivir (A) is used to treat influenza viruses, not herpes. Lamivudine (B) is used for HIV and hepatitis B, not herpes. Cidofovir (D) is used for cytomegalovirus and other viral infections, but not the first line for herpes. Valacyclovir is the most appropriate choice due to its effectiveness and safety profile in treating herpes simplex virus infections.

Correct Answer: D

Rationale: The correct answer is D: Foscarnet. Foscarnet is a pyrophosphate analog that inhibits both DNA polymerase and reverse transcriptase, making it effective against cytomegalovirus (CMV) infections in AIDS patients. Acyclovir (A) and Valacyclovir (B) are antiviral drugs used for herpes infections, not CMV. Amantadine (C) is an antiviral used for influenza, not CMV. Therefore, Foscarnet is the correct choice for treating CMV in AIDS patients.

Correct Answer: A

Rationale: Rationale: 1. Piperazine is the correct answer as it acts as a cholinergic agonist in nematodes, causing spastic paralysis by mimicking acetylcholine. 2. Pyrantel pamoate works by depolarizing neuromuscular junctions, not through cholinergic agonism. 3. Mebendazole and Albendazole inhibit microtubule synthesis in worms, leading to impaired glucose uptake, not cholinergic effects.