Gastrointestinal disturbances, e.g. nausea, dyspepsia, abdominal pain, vomiting, and diarrhea are the most frequent adverse effects of Clarithromycin but are usually mild and less frequent than with erythromycin. Other adverse effects are taste disturbances, stomatitis, glossitis, and tooth decoloration. Transient elevations of liver enzyme values, cholestatic jaundice, and hepatitis have been reported. Headache and rashes from mild skin eruptions to, rarely, Stevens-Johnson syndrome have occurred. There also have been reports of transient CNS effects such as anxiety, dizziness, insomnia, hallucinations, and confusion. Hearing loss has been reported occasionally and is usually reversible. Other effects include hypoglycemia and thrombocytopenia. Interstitial nephritis and renal failure have been reported rarely.
Thrombocytopenic purpura, corneal opacities which is usually reversible upon discontinuation of the treatment, pseudomembranous colitis associated with
Clostridium difficile developed in a child receiving Clarithromycin, acute psychoses, pancreatitis, QT prolongation and Torsade de Pointes, fever associated with Clarithromycin and leukocytoclastic vasculitis have also been reported.