ATI RN
Chemotherapy drugs Questions
Question 1 of 5
The combination of trimethoprim and sulfamethoxazole is effective against which one of the following opportunistic infections in the AIDS patient?
Correct Answer: C
Rationale: Trimethoprim-sulfamethoxazole (TMP-SMX) is effective against Toxoplasmosis, a common opportunistic infection in AIDS patients, by inhibiting folate synthesis in the parasite Toxoplasma gondii.
Question 2 of 5
Supplementary folinic acid may prevent anemia in folate-deficient persons who use this drug; it is a weak base, and achieves tissue levels similar to those in plasma
Correct Answer: D
Rationale: Trimethoprim inhibits dihydrofolate reductase, potentially causing folate deficiency anemia, which can be prevented with folinic acid supplementation.
Question 3 of 5
The mechanism of high - level INH resistance of M tuberculosis is
Correct Answer: B
Rationale: High-level isoniazid (INH) resistance is most commonly due to reduced expression of the katG gene, which encodes catalase-peroxidase needed to activate INH.
Question 4 of 5
Once-weekly administration of this antibiotic has prophylactic activity against bacteremia due to M avium complex in AIDS patients.
Correct Answer: A
Rationale: Azithromycin, given once weekly, is effective prophylaxis against MAC bacteremia in AIDS patients due to its long half-life and activity against mycobacteria.
Question 5 of 5
Which one of the following statements about fluconazole is most accurate?
Correct Answer: D
Rationale: Fluconazole inhibits lanosterol demethylation, disrupting fungal cell membrane synthesis, and is accurate among the options provided.