Clindamycin Dosing for Adults with Bacterial Infections
For adults with bacterial infections, clindamycin should be dosed at 150-300 mg orally every 6 hours for serious infections, and 300-450 mg orally every 6 hours for more severe infections. 1
Oral Dosing
- For serious infections: 150-300 mg every 6 hours 1
- For more severe infections: 300-450 mg every 6 hours 1
- Take with a full glass of water to avoid esophageal irritation 1
- For β-hemolytic streptococcal infections, treatment should continue for at least 10 days 1
Intravenous Dosing
- For complicated skin and soft tissue infections: 600 mg IV every 8 hours 2
- For intra-abdominal infections: 600-900 mg IV every 8 hours 2
- For osteomyelitis: 600 mg IV every 8 hours 2
- For pneumonia: 600 mg IV every 8 hours 2
Indication-Specific Dosing
Skin and Soft Tissue Infections
- Purulent cellulitis: 300-450 mg PO three times daily 2
- Complicated SSTI: 600 mg IV/PO three times daily 2
- For MRSA infections: 600 mg IV every 8 hours or 300-450 mg PO four times daily 2
Bone and Joint Infections
- Osteomyelitis: 600 mg IV/PO three times daily 2
- Septic arthritis: 600 mg IV/PO three times daily 2
- Duration: Minimum 8-week course for osteomyelitis 2
- Some experts recommend adding rifampin 600 mg daily or 300-450 mg twice daily for bone infections after clearance of bacteremia 2
Pneumocystis Pneumonia (PCP)
- For patients weighing <60 kg: 600 mg IV every 6 hours for 10 days, then 300-450 mg orally every 6 hours to complete 21 days 2
- Used in combination with primaquine for mild to moderate PCP 2
Special Considerations
Bactericidal Activity
- 300 mg dosing every 8 hours provides bactericidal activity against S. aureus for >85% of the dosing interval 3
- 300 mg every 12 hours provides bactericidal activity against S. aureus for >50% of the dosing interval 3
- Both regimens provide adequate coverage against S. pneumoniae and B. fragilis 3
Side Effects and Monitoring
- Monitor for diarrhea, which may indicate Clostridioides difficile infection; discontinue if significant diarrhea occurs 1
- Higher doses (600 mg) are associated with more severe and prolonged gastrointestinal side effects compared to lower doses (300 mg) 4
- Nearly 98% of patients may experience some gastrointestinal side effects with oral clindamycin 4
Efficacy Considerations
- Clindamycin has excellent activity against anaerobic bacteria, particularly β-lactamase-producing Bacteroides species 5, 6
- It is effective against aerobic gram-positive cocci, including group B streptococci 5
- For mixed infections, clindamycin is often combined with agents active against gram-negative bacteria 2, 7
Pediatric Dosing (For Reference)
- Serious infections: 8-16 mg/kg/day divided into three or four equal doses 1
- More severe infections: 16-20 mg/kg/day divided into three or four equal doses 1
- For MRSA infections: 10-13 mg/kg/dose every 6-8 hours, not to exceed 40 mg/kg/day 2
Clinical Pearls
- Clindamycin should be dosed based on total body weight regardless of obesity 1
- For anaerobic lung infections, clindamycin has shown superior efficacy compared to penicillin, especially against penicillin-resistant Bacteroides 6
- The 600 mg IV every 8 hours dosing is recommended for most serious infections requiring parenteral therapy 2