Nursing Pharmacology: Antibacterial Drug Praction Questions

Trimethoprim (Primsol):
1. Inhibitor of bacterial dihydrofolate reductase.
2. Trimethoprim + sulfamethoxazole (clotrimazole) acts on sequential steps in tetrahydrofolic acid synthesis.
3. Both
4. Neither
Antimicrobial action of the combination trimethoprim-sulfamethoxazole (Bactrim DS and others):
1. Trimethoprim is a highly selective inhibitor of bacterial dihydrofolate reductase, compared to human dihydrofolate reductase (100,000 times more selective)
2. Optimal ratios for trimethoprim and sulfamethoxazole depend on their MIC which is the lowest concentration of the antibacterial drug needed to prevent "visible" growth of the bacterial test strain.
3. Both
4. Neither
With trimethoprim-sulfamethoxazole combination sulfamethoxazole exhibits pharmacokinetic properties such that the concentrations of the two agents should remain similar in the body over an extended period.
1. True
2. False
Where administration of sulfamethoxazole by itself or trimethoprim by itself results in a bacteriostatic effect, the combination may be bacteriocidal.
1. True
2. False
Antimicrobial spectrum of action of trimethoprim is comparable to that of sulfamethoxazole.
1. True
2. False
Clinically resistant organisms to trimethoprim-sulfamethoxazole include/includes:
1. Pseudomonas aeruginosa
2. Enterococci
3. Bacterioides fragilis
4. A & B
5. B & C
6. A & C
7. A, B & C
Susceptible to trimethoprim-sulfamethoxazole administration (usually):
1. S. aureus
2. Staphylococcus epidermidis
3. Both
4. Neither
Trimethoprim pharmacokinetics:
1. Protein binding: about 40%
2. Easily enters the central nervous system
3. Both
4. Neither
About 60% of administered trimethoprim dose is excreted in the urine.
1. True
2. False
Sulfamethoxazole elimination:
1. About 25% to 50% of a sulfamethoxazole dose will be excreted in the urine.
2. Excretion rates and urinary concentrations of both trimethoprim and sulfamethoxazole are decreased notably in uremic patients.
3. Both
4. Neither