Pharmacology · patient case question
Which organism is characteristically resistant to clindamycin?
Patient case: Choosing and stopping drugs
demo: Series of prescribing decisions
chief: Several patients seen in one session raise questions about antibiotic choice, analgesia and anticoagulation.
history: One patient has a spreading odontogenic infection unresponsive to five days of empirical antibiotics. Another takes rivaroxaban for atrial fibrillation. A third developed a widespread blistering rash and mucosal ulceration a week after starting a new medication.
meds: Varies by patient.
findings: Not applicable.
Show answer and explanation
Correct answer: D. Pseudomonas aeruginosa
- A. Viridans streptococci are generally susceptible to clindamycin, which is why it was long used for endocarditis prophylaxis in penicillin allergy.
- B. Peptostreptococcus is an anaerobic gram-positive coccus, well within clindamycin's spectrum.
- C. Prevotella is an anaerobe and generally susceptible.
- D. Correct. Clindamycin has no useful activity against aerobic gram-negative bacilli, and Pseudomonas aeruginosa is intrinsically resistant. Its strength is against gram-positive cocci and anaerobes, which is why it suits odontogenic infection in penicillin-allergic patients.