Cephalexin vs Clindamycin

Cephalexin is highly effective for uncomplicated skin infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) and Streptococcus species. It achieves cure rates above 90% for cellulitis and simple abscesses when the bacteria are susceptible.

Clindamycin covers a broader range of pathogens including many MRSA strains and anaerobic bacteria. IDSA guidelines recommend clindamycin as an oral option for purulent skin infections where MRSA is common locally. However, inducible clindamycin resistance (detected by D-test) can limit its usefulness in some MRSA strains.

For dental infections and certain intra-abdominal infections, clindamycin's anaerobic coverage gives it an advantage that cephalexin cannot match.

Cephalexin is generally well tolerated with mild GI side effects including nausea, diarrhea, and stomach upset in about 5-10% of patients. Allergic reactions can occur, and patients with severe penicillin allergy should use caution, though cross-reactivity with first-generation cephalosporins is low (1-2%).

Clindamycin carries a significant risk of Clostridioides difficile (C. diff) infection, a potentially severe form of antibiotic-associated diarrhea. C. diff risk is higher with clindamycin than with most other oral antibiotics. Symptoms include watery diarrhea, fever, and abdominal pain; severe cases require hospitalization.

Both antibiotics can cause rash and GI upset, but the C. diff risk with clindamycin is a meaningful safety consideration.

Both cephalexin and clindamycin are available as affordable generics. Cephalexin typically costs $8-$20 for a course of treatment, and clindamycin costs $10-$30. Both are covered by most insurance plans on preferred generic tiers.

Cephalexin is typically taken 2-4 times daily depending on the infection. Clindamycin is usually taken 3-4 times daily. Both require multi-day courses, commonly 7-10 days for skin infections.

Neither drug has significant food interactions, though taking both with food can reduce stomach upset. Clindamycin should be taken with a full glass of water to prevent esophageal irritation.

If your infection is likely caused by common streptococcal or methicillin-susceptible staph bacteria, cephalexin is an excellent first choice with a well-established safety profile and low C. diff risk.

If MRSA is suspected (purulent infection, prior MRSA history, local MRSA prevalence), clindamycin provides broader coverage. Your doctor may order a wound culture to guide the choice.

Always tell your doctor about any antibiotic allergies, particularly to penicillin or cephalosporins. Complete the full course even if you feel better before finishing.