Formulary
Clindamycin: Uses, Dosing, Side Effects and Indian Brand Names
Clindamycin is a lincosamide antibiotic with excellent Gram-positive and anaerobic coverage, valued for its anti-toxin effect in toxin-mediated diseases and superior bone penetration, but carrying the highest risk of C. difficile colitis.
MedNext Academy | 4 min read
Clinically reviewed by Awaiting clinical review
Clindamycin: Uses, Dosing, Side Effects and Indian Brand Names
Clindamycin is a lincosamide antibiotic with excellent Gram-positive and anaerobic coverage, valued for its anti-toxin effect in toxin-mediated diseases and superior bone penetration, but carrying the highest risk of C. difficile colitis.
NEET PG High-Yield: 50S ribosomal subunit (overlaps with macrolide binding site). Anti-toxin effect (suppresses TSST-1, PVL, alpha-toxin) -- key for TSS and necrotising fasciitis. C. difficile colitis (classic association -- pseudomembranous colitis). Excellent bone penetration (osteomyelitis). D-test: inducible clindamycin resistance detection (erm gene-mediated methylation of 23S rRNA). Erythromycin-clindamycin antagonism (same binding site). Eagle effect of penicillin in high-inoculum strep infections -- reason to add clindamycin.
Clinical overview
Clindamycin is a lincosamide antibiotic with excellent activity against Gram-positive cocci (including many community-acquired MRSA strains) and most clinically significant anaerobes (Bacteroides fragilis, Clostridium perfringens, Prevotella, Fusobacterium), but notably NOT Clostridium difficile -- and indeed clindamycin is one of the antibiotics most strongly associated with precipitating C. difficile infection. Its anti-toxin property, which suppresses bacterial exotoxin production at sub-MIC concentrations, makes it uniquely valuable in toxin-mediated diseases such as streptococcal toxic shock syndrome, necrotising fasciitis (combined with penicillin), and gas gangrene. In Indian practice, clindamycin is widely used for dental infections, skin and soft tissue infections (particularly CA-MRSA boils and abscesses), bone and joint infections (excellent bone penetration), aspiration pneumonia, and pelvic infections. It is an important alternative in penicillin-allergic patients for surgical prophylaxis and endocarditis prophylaxis. Clindamycin penetrates bone exceptionally well, making it a first-choice agent for osteomyelitis. The most significant adverse effect is Clostridioides difficile-associated diarrhoea (CDAD), which can range from mild diarrhoea to life-threatening pseudomembranous colitis. Any antibiotic can cause CDAD, but clindamycin, fluoroquinolones, and broad-spectrum cephalosporins carry the highest risk. The D-test (double-disc diffusion test) is essential to detect inducible clindamycin resistance in staphylococci that are erythromycin-resistant but appear clindamycin-susceptible.
Pharmacological class
Clindamycin belongs to the Lincosamide Antibiotics class. Binds to the 50S ribosomal subunit (23S rRNA, overlapping with the macrolide and chloramphenicol binding sites), inhibiting peptide bond formation during translation. Clindamycin is primarily bacteriostatic, but may be bactericidal at higher concentrations against susceptible organisms. Importantly, it suppresses bacterial toxin production (anti-toxin effect) -- reducing alpha-toxin (Clostridium perfringens), toxic shock syndrome toxin (TSST-1), and Panton-Valentine leucocidin (PVL) production by staphylococci.
Indian brand names and formulations
Available as: Dalacin C (Pfizer), Clincin (Alkem), Clindasol (Solace Biotech), Clindac (Galderma, topical).
Capsules: 150 mg, 300 mg. Injection: 150 mg/mL (2 mL and 4 mL ampoules). Topical gel: 1%. Topical lotion: 1%. Vaginal cream: 2%. Vaginal suppositories: 100 mg.
Regulatory status
Clindamycin is classified under Schedule H in India under the Drugs and Cosmetics Act, 1940. Prescription-only. Topical formulations for acne widely used in Indian dermatology practice.
Indications
- Skin and soft tissue infections (including CA-MRSA, if susceptible)
- Osteomyelitis (excellent bone penetration)
- Dental infections and peritonsillar abscess
- Aspiration pneumonia and lung abscess (anaerobic coverage)
- Pelvic inflammatory disease and pelvic abscess (with gentamicin)
- Toxin-mediated diseases: streptococcal TSS, necrotising fasciitis (with penicillin), gas gangrene
- Endocarditis prophylaxis in penicillin-allergic patients (600 mg before dental procedures)
- Malaria (P. falciparum, with quinine -- for pregnant women in first trimester where doxycycline is contraindicated)
- Acne vulgaris (topical)
Dosing
Adults oral: 150-300 mg four times daily (serious infections: 300-450 mg four times daily). IV: 600-900 mg every 8 hours (maximum 4.8 g/day). Endocarditis prophylaxis: 600 mg oral 30-60 min before procedure. Topical (acne): apply gel/lotion twice daily. Children: 8-25 mg/kg/day in 3-4 divided doses.
Contraindications
- History of Clostridioides difficile-associated diarrhoea or pseudomembranous colitis
- Known hypersensitivity to clindamycin or lincomycin
- Inflammatory bowel disease (increased C. difficile susceptibility)
Adverse effects
- Clostridioides difficile-associated diarrhoea and pseudomembranous colitis (most important -- clindamycin is the classic cause; can occur up to 2 months after discontinuation)
- Diarrhoea (non-C. difficile, common)
- Nausea, vomiting, and abdominal pain
- Rash
- Elevated liver transaminases
- Oesophageal ulceration (take capsules with a full glass of water; do not lie down after)
- Local reactions (pain at IM injection site, thrombophlebitis with IV)
Drug interactions
- Neuromuscular blockers (succinylcholine, pancuronium): clindamycin enhances neuromuscular blockade; risk of prolonged paralysis post-operatively
- Erythromycin: antagonistic -- both compete for the same 50S ribosomal binding site; do NOT combine
- Kaolin-pectin (antidiarrhoeal): reduces clindamycin absorption; separate by 2 hours
- Cyclosporine: clindamycin may reduce cyclosporine levels
Pregnancy and lactation
Category B. Crosses the placenta but no teratogenic effects reported. Used in pregnancy for anaerobic infections, bacterial vaginosis (oral or vaginal), and as part of malaria treatment when doxycycline is contraindicated.
Exam-style clinical scenario
A patient with streptococcal necrotising fasciitis is started on IV penicillin. Why should clindamycin be added? In necrotising fasciitis with high bacterial burden, penicillin efficacy is reduced because bacteria in stationary phase express fewer PBPs (Eagle effect/inoculum effect). Clindamycin's ribosomal mechanism is unaffected by growth phase, and it directly suppresses toxin production (streptococcal pyrogenic exotoxins, superantigens) that drive the systemic inflammatory response and shock.
Cost in India
Rs 40-80 for a strip of 10 capsules (300 mg). IV: Rs 30-60 per 600 mg ampoule. Topical gel: Rs 100-200 per tube.
Clinical governance
Author: MedNext Editorial Team. Clinical reviewer: Awaiting clinical review. Jurisdiction: India (Drugs and Cosmetics Act, 1940). Sources: CIMS India, Indian Pharmacopoeia. Publication state: Awaiting clinical review. Correction: Report errors at support@mednext.academy.
Frequently Asked Questions
What is the D-test and why is it important?
The D-test (double-disc diffusion test) places erythromycin and clindamycin discs 15-20 mm apart on a culture plate. If the zone of inhibition around clindamycin is flattened (D-shaped) on the side facing erythromycin, it indicates inducible clindamycin resistance mediated by the erm gene (which methylates the 23S rRNA binding site). A D-test positive result means clindamycin may fail in vivo despite appearing susceptible in standard testing. This test must be performed for any staphylococcal isolate that is erythromycin-resistant but clindamycin-susceptible.
Why is clindamycin combined with penicillin in necrotising fasciitis?
Two reasons: (1) The Eagle effect -- penicillin's bactericidal activity depends on active bacterial cell division and PBP expression. In high-inoculum infections (like necrotising fasciitis), many bacteria are in stationary phase with fewer PBPs, reducing penicillin efficacy. Clindamycin works regardless of growth phase. (2) Anti-toxin effect -- clindamycin suppresses production of streptococcal pyrogenic exotoxins (superantigens) that drive toxic shock. This combination is now standard of care.
Why does clindamycin cause C. difficile colitis more than other antibiotics?
Clindamycin has excellent activity against normal anaerobic gut flora (Bacteroides, Prevotella) that compete with C. difficile for nutrients and ecological niches. When this protective flora is eliminated by clindamycin, C. difficile (which is resistant to clindamycin) proliferates unopposed, producing toxins A and B that cause colitis. The broad anti-anaerobic spectrum of clindamycin makes this ecological disruption particularly severe.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
Test yourself on Clindamycin
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

