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Clindamycin: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on Dec 28, 2019.

1. How it works

  • Clindamycin is an antibiotic that may be used to treat a wide range of infections including those involving gram positive and anaerobic bacteria (anaerobic means living without air).
  • Clindamycin works by inhibiting bacterial protein synthesis, which inhibits bacterial growth.
  • Clindamycin has a bacteriostatic effect (stops bacteria from reproducing, but doesn't necessarily kill them).
  • Clindamycin belongs to the class of antibiotics known as lincosamide or lincomycin antibiotics.

2. Upsides

  • Usually reserved for the treatment of serious infections caused by susceptible anaerobic bacteria, such as those occurring in the abdomen, gastrointestinal tract, lower respiratory tract, on the skin, and in the genitourinary area.
  • Effective against a number of different gram positive and anaerobic bacteria, including susceptible strains of Staphylococcus aureus (methicillin-susceptible strains only), Streptococcus pneumoniae (penicillin-susceptible strains only), S. pyogenes, Clostridium perfringens, Fusobacterium necrophorum, F. nucleatum, Peptostreptococcus anaerobius, Prevotella melaninogenica.
  • For infections caused by susceptible strains of streptococci, pneumococci, or staphylococci, clindamycin is usually reserved for penicillin-allergic patients or other patients in whom penicillin is unsuitable.
  • Generic clindamycin is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Abdominal pain, pain in the esophagus, nausea, vomiting, an unpleasant or metallic taste, skin rashes, and liver function test abnormalities.
  • All antibiotics carry a risk of severe diarrhea caused by an overgrowth of Clostridium difficile bacteria. The risk may be higher with clindamycin compared with some other antibiotics. Further investigations are warranted if severe diarrhea occurs within several months of clindamycin administration. Symptoms include watery or bloody stools, stomach cramps or fever.
  • Not suitable for the treatment of meningitis because it does not reach high enough concentrations in the cerebrospinal fluid (the fluid around the brain and spinal cord).
  • May not be suitable for some people including those with a history of gastrointestinal disease (such as colitis) or a history of allergic reactions. Rarely, may cause severe hypersensitivity reactions and anaphylaxis.
  • Be cautious when using in patients with kidney or liver disease. Although dosage reductions are not specifically recommended, liver and kidney function should be monitored.
  • May interact with a number of different drugs including neuromuscular blocking agents (such as succinylcholine, vecuronium), those that inhibit or induce CYP3A4 hepatic enzymes, and erythromycin.
  • Clindamycin needs to be administered every six hours.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

4. Bottom Line

Clindamycin is an antibiotic that is usually reserved for treating anaerobic infections or other serious infections caused by gram positive bacteria in penicillin-allergic people. The risk of C. difficile-associated diarrhea may be higher with clindamycin compared with some other antibiotics.

5. Tips

  • May be taken with or without food. Take with a full glass of water.
  • Take exactly as directed and for the duration intended. Finish the course of treatment prescribed.
  • Only use when prescribed by a doctor to treat infections caused by susceptible bacteria as improper use increases the risk of resistant bacteria developing. Clindamycin does not treat infections caused by viruses, such as a cold or the flu.
  • Report any instances of severe or persistent diarrhea, occurring either during clindamycin administration or within a few months following discontinuation to your doctor.
  • Call your doctor immediately if you develop a severe rash.
  • Some strengths (eg, 150mg capsules) contain FD & C Yellow No. 5 (tartrazine) which may cause allergic reactions; people with an aspirin sensitivity may be more at risk.

6. Response and Effectiveness

  • Peak concentrations are reached within 45 minutes; however, it may take up to 48 hours before infection-related symptoms start to abate.

7. Interactions

Medicines that interact with clindamycin may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with clindamycin. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with clindamycin include:

  • birth control treatments, such as estradiol, levonorgestrel
  • botulinum toxin A
  • bowel cleansing agents such as sodium picosulfate
  • CYP3A4 inducers, such as erythromycin, diltiazem, itraconazole, ritonavir, or verapamil
  • grapefruit juice
  • kaolin
  • lactobacillus
  • neuromuscular blocking agents, such as atracurium or vecuronium
  • mycophenolate mofetil
  • vaccinations, such as BCG and Cholera.

Note that this list is not all-inclusive and includes only common medications that may interact with clindamycin. You should refer to the prescribing information for clindamycin for a complete list of interactions.


Clindamycin. Revised 07/2019.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use clindamycin only for the indication prescribed.

Copyright 1996-2020 Revision date: December 28, 2019.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.