Side Effects of Cleocin (oral clindamycin)

Cleocin (clindamycin) is an oral antibiotic used to treat serious infections caused by susceptible bacteria. It is most often used to treat penicillin-allergic patients or in other situations where penicillin or other alternative antibiotics cannot be used. 

Examples of infections that are treated with Cleocin include serious respiratory tract infections (for example, empyema, pneumonitis, and lung abscess), serious skin and soft tissue infections, and female pelvic and genital tract infections (for example, endometritis), and ovarian abscess. 

It is effective against several types of bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, Staphylococcus epidermidis, and Propionibacterium acnes. It reduces growth of bacteria by interfering with their ability to make proteins.

Common side effects of Cleocin include

• stomach pain,
• diarrhea,
• nausea,
• vomiting,
• metallic taste,
• low blood pressure,
• rash, and
• itching.

Serious side effects of Cleocin include

• Clostridium difficile associated diarrhea (CDAD) which causes
  • inflammation of the colon (pseudomembranous colitis; symptoms include diarrhea, fever, abdominal pain, and possibly shock),
  • serious allergic reactions,
  • blood disorders,
  • Stevens-Johnson syndrome, and
  • toxic epidermal necrolysis.

Drug interactions of Cleocin include neuromuscular blocking drugs (for example, pancuronium and vecuronium, which are used during surgery) because Cleocin may act as a neuromuscular blocker. This means it can increase the action of neuromuscular blocking drugs. 

The frequency of congenital abnormalities was not increased when pregnant women used Cleocin during the second and third trimesters. Cleocin should not be used during the first trimester of pregnancy unless it is clearly needed because it has not been properly evaluated during the first trimester of pregnancy. 

Cleocin is excreted in breast milk and should not be used by nursing mothers or breastfeeding should be stopped.

The most common side effects of clindamycin are

• stomach pain, and
• diarrhea.

Cleocin also frequently causes

• nausea,
• vomiting,
• metallic taste,
• itching
• low blood pressure,
• rash, and
• itching.

Clindamycin causes Clostridium difficile associated diarrhea (CDAD) because it can alter the normal bacteria in the colon and encourage overgrowth Clostridium difficile, a bacteria which causes inflammation of the colon (pseudomembranous colitis).

Patients who develop signs of pseudomembranous colitis after starting clindamycin (diarrhea, fever, abdominal pain, and possibly shock) should contact their physician immediately.

Other serious side effects of clindamycin include:

• serious allergic reactions
• blood disorders
• Stevens-Johnson syndrome
• toxic epidermal necrolysis

The following reactions have been reported with the use of clindamycin.

• Infections and Infestations: Clostridium difficile colitis
• Gastrointestinal: Abdominal pain, pseudomembranous colitis, esophagitis, nausea, vomiting, and diarrhea. The onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment. Esophageal ulcer has been reported. An unpleasant or metallic taste has been reported after oral administration.
• Hypersensitivity Reactions: Generalized mild to moderate morbilliform-like (maculopapular) skin rashes are the most frequently reported adverse reactions. Vesiculobullous rashes, as well as urticaria, have been observed during drug therapy. Severe skin reactions such as Toxic Epidermal Necrolysis, some with fatal outcome, have been reported. Cases of Acute Generalized Exanthematous Pustulosis (AGEP), erythema multiforme, some resembling Stevens-Johnson syndrome, anaphylactic shock, anaphylactic reaction and hypersensitivity have also been reported.
• Skin and Mucous Membranes: Pruritus, vaginitis, angioedema and rare instances of exfoliative dermatitis have been reported. (See Hypersensitivity Reactions.)
• Liver: Jaundice and abnormalities in liver function tests have been observed during clindamycin therapy.
• Renal: Although no direct relationship of clindamycin to renal damage has been established, renal dysfunction as evidenced by azotemia, oliguria, and/or proteinuria has been observed.
• Hematopoietic: Transient neutropenia (leukopenia) and eosinophilia have been reported. Reports of agranulocytosis and thrombocytopenia have been made. No direct etiologic relationship to concurrent clindamycin therapy could be made in any of the foregoing.
• Immune System: Drug reaction with eosinophilia and systemic symptoms (DRESS) cases have been reported.
• Musculoskeletal: Cases of polyarthritis have been reported.

• Clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents. Therefore, it should be used with caution in patients receiving such agents.
• Clindamycin is metabolized predominantly by CYP3A4, and to a lesser extent by CYP3A5, to the major metabolite clindamycin sulfoxide and minor metabolite N-desmethylclindamycin. Therefore inhibitors of CYP3A4 and CYP3A5 may increase plasma concentrations of clindamycin and inducers of these isoenzymes may reduce plasma concentrations of clindamycin.
• In the presence of strong CYP3A4 inhibitors, monitor for adverse reactions. In the presence of strong CYP3A4 inducers such as rifampicin, monitor for loss of effectiveness.
• In vitro studies indicate that clindamycin does not inhibit CYP1A2, CYP2C9, CYP2C19, CYP2E1 or CYP2D6 and only moderately inhibits CYP3A4.
• Antagonism has been demonstrated between clindamycin and erythromycin in vitro.
• Because of possible clinical significance, these two drugs should not be administered concurrently.