Antimicrobial and Chemotherapeutic Agents Flashcards
7 cards from real Pharmacology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Antimicrobial and Chemotherapeutic Agents flashcards as text
A patient requires treatment for Pneumocystis jirovecii pneumonia (PCP). Which drug is first-line therapy?
Answer: Trimethoprim-sulfamethoxazole (TMP-SMX)
TMP-SMX (Bactrim) is the drug of choice for both treatment and prophylaxis of PCP because Pneumocystis jirovecii lacks the ability to synthesize folate from external sources.
Which antiviral agent is used for CMV (cytomegalovirus) retinitis in immunocompromised patients and works by inhibiting viral DNA polymerase?
Answer: Ganciclovir
Ganciclovir is phosphorylated by CMV-encoded kinase and inhibits viral DNA polymerase; it is the drug of choice for CMV disease in immunocompromised patients.
A patient on linezolid for VRE infection is given serotonergic medications. What potentially fatal adverse interaction must be monitored?
Answer: Serotonin syndrome
Linezolid weakly inhibits monoamine oxidase (MAO), and when combined with serotonergic drugs (SSRIs, SNRIs, meperidine), can precipitate potentially fatal serotonin syndrome.
Which beta-lactam antibiotic is specifically active against Pseudomonas aeruginosa and other gram-negative organisms but has poor gram-positive coverage?
Answer: Aztreonam
Aztreonam is a monobactam that selectively binds PBP3 of aerobic gram-negative rods including Pseudomonas; it has no activity against gram-positive or anaerobic organisms.
Primaquine is used to eliminate the hypnozoite (dormant liver) stage of Plasmodium vivax malaria. Before prescribing, the clinician must first screen for:
Answer: G6PD deficiency
Primaquine causes severe hemolytic anemia in patients with G6PD deficiency because the drug generates oxidative stress that RBCs lacking G6PD cannot neutralize.
Which antibiotic inhibits bacterial cell wall synthesis by binding to penicillin-binding protein 2a (PBP2a), making it effective against MRSA?
Answer: Ceftaroline
Ceftaroline is the only FDA-approved cephalosporin with anti-MRSA activity because it has high affinity for PBP2a, the altered target that confers methicillin resistance.
A patient develops muscle pain and weakness with elevated creatine kinase (CK) levels while on daptomycin. The nurse should recognize this as:
Answer: Myopathy/rhabdomyolysis
Daptomycin can cause skeletal muscle toxicity (myopathy), characterized by muscle pain, weakness, and elevated CK levels; CK should be monitored weekly during therapy.