For Healthcare Professionals. Applies to clarithromycin: oral powder for reconstitution, oral tablet, oral tablet extended release. General. The most common side effects were abdominal pain/discomfort, diarrhea, nausea, vomiting, and dysgeusia/taste perversion. In immunocompromised patients treated with higher doses of this drug (1 to 2 g/day), the most common side effects were nausea. Background: Clarithromycin is a macrolide antibiotic very similar to erythromycin in structure and spectrum of activity. It has gained increasing use since its release in Canada in May 1992, partly because it is promoted as having less potential for drug interactions and adverse effects. Clarithromycin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: diarrhea; nausea; vomiting; stomach pain; heartburn; gas; change in taste; headache; Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment: chest pain, shortness of breath, trouble breathing. Clarithromycin. GI effects, general (13%) 1-10% Clarithromycin. Headache (6%) Rash (children 3%) Abdominal pain (adults 2%, children 3%) Abnormal taste (adults 3-7%) Diarrhea (3-6%) Dyspepsia (2%) Heartburn (adults 2%) GI intolerance (oral-dose related) Nausea (adults 3-6%) Vomiting (adults 1%; children 6%) Decreased WBC, elevated BUN (4%), elevated PT (1%) Lansoprazole. Fatigue ( 3%) Headache. Clarithromycin is an antibiotic. It's used to treat chest infections, such as pneumonia, skin problems such as cellulitis, and ear infections. It's also used to get rid of Helicobacter pylori, a bacteria that can cause stomach ulcers. Clarithromycin is sometimes used by people who have an allergy to penicillin and antibiotics similar to penicillin, like amoxicillin. Effects of clarithromycin on other medicinal products. Antiarrhythmics. There have been post-marketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during co-administration of clarithromycin with these drugs. Serum levels of these medications should be monitored during. Clarithromycin side effects. Get emergency medical help if you have signs of an allergic reaction to clarithromycin: (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling). Call your doctor at once if you have: severe stomach pain. clarithromycin decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug. sofosbuvir/velpatasvir. clarithromycin will increase the level or effect of sofosbuvir/velpatasvir by affecting. Clarithromycin oral tablet doesn’t cause drowsiness. However, it can cause other side effects. More common side effects. The more common side effects of clarithromycin oral tablet can include: Find patient medical information for clarithromycin oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings.