Clindamycin !
A lincosamide for anaerobes, staphylococci and streptococci, added in necrotising fasciitis to stop toxins. Its main danger is C. difficile colitis.
Updated 2026-11-01
The figure shows clindamycin bound to the 50S ribosomal subunit of Escherichia coli, at the peptidyl transferase centre.
Mechanism of action
Clindamycin binds the 23S rRNA at the peptidyl transferase centre of the 50S subunit, overlapping the macrolide site, and stops the peptide bond from forming. Protein synthesis, toxin production included, comes to a halt. Bacteria with methylated 23S rRNA resist macrolides and can switch on clindamycin resistance too, which the D-zone test detects.
- Spreads into tissues, including bone and abscesses
- Binds the peptidyl transferase centre of the 50S subunit
- Peptide bonds and toxins are no longer made
- Bacterial growth stops
Pharmacokinetics
- Absorption
- Well absorbed by mouth; also given IV and IM, and as vaginal and skin forms.
- Distribution
- Wide in fluids and tissues, including bone; does not reach useful levels in the cerebrospinal fluid.
- Metabolism
- Liver, mainly by CYP3A4.
- Half-life
- About 2.4 hours.
Indications
- Skin and soft-tissue infections, including some MRSA, when susceptible Cellulitis of the leg →
- Bone and joint infections Osteomyelitis →
- Bacterial vaginosis (vaginal and oral forms) Bacterial vaginosis →
- Anaerobic infections: aspiration pneumonia, lung abscess, intra-abdominal and pelvic infections (with other drugs)
- Necrotising fasciitis, with a β-lactam (WHO first choice)
Adverse effects
Common
- Diarrhoea
- Nausea, abdominal pain and metallic taste
- Rash; oesophageal irritation if the capsule sticks
Contraindications
- Allergy to clindamycin or lincomycin
- Not used for meningitis (does not reach the cerebrospinal fluid)
Key interactions
- Strong CYP3A4 inhibitors or inducers
- Change clindamycin levels.
- Neuromuscular blockers
- Clindamycin can enhance their effect.
What is monitored
- Number and type of stools, during and for weeks after treatment
- Liver and kidney function and blood counts in long courses
- Skin for rash
Administration and safety
- Capsules are swallowed with a full glass of water, not just before lying down
- The IV form is diluted and infused, not given as a rapid push
- Watch for look-alike names: clindamycin and clarithromycin
Nursing care
- Teach to report frequent watery or bloody stools, even after the course ends
- Check stool frequency in hospital
- Ask about previous C. difficile infection
- Assess the IV site
Pregnancy and breastfeeding
Use in the second and third trimesters has not been linked to more birth defects; in the first trimester it is used only if clearly needed.
Test yourself
Think of the answer, then tap the question to see it.
Which adverse effect is in the boxed warning of clindamycin?
Clostridioides difficile infection, which may be fatal.
Why is clindamycin not used for meningitis?
It does not reach adequate concentrations in the cerebrospinal fluid.
Why is clindamycin added in necrotising fasciitis?
It blocks bacterial protein synthesis and so reduces toxin production.
Related drugs
Related conditions
← Back to the class: Lincosamides
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - CLINDAMYCIN HYDROCHLORIDE capsule (DailyMed (U.S. National Library of Medicine), 2026); Clindamycin: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025); Clindamycin bound to the 50S subunit (RCSB Protein Data Bank, 2026).
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Representative model, for educational purposes only.