Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- Drug class
- Macrolide Antimicrobial [EPC], Cytochrome P450 3A4 Inhibitors [MoA], Cytochrome P450 3A Inhibitors [MoA], P-Glycoprotein Inhibitors [MoA]
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 197517
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
Clarithromycin is a macrolide antimicrobial indicated for mild to moderate infections caused by designated, susceptible bacteria in the following: Acute Bacterial Exacerbation of Chronic Bronchitis in Adults ( 1.1 ) Acute Maxillary Sinusitis ( 1.2 ) Community-Acquired Pneumonia ( 1.3 ) Pharyngitis/Tonsillitis ( 1.4 ) Uncomplicated Skin and Skin Structure Infections ( 1.5 ) Acute Otitis Media in Pediatric Patients ( 1.6 ) Treatment and Prophylaxis of Disseminated Mycobacterial Infections ( 1.7 ) Helicobacter pylori Infection and Duodenal Ulcer Disease in Adults ( 1.8 ) Limitations of Use To reduce the development of drug-resistant bacteria and maintain the effectiveness of clarithromycin tablets and other antibacterial drugs, clarithromycin tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. ( 1.9 ) 1.1 Acute Bacterial Exacerbation of Chronic Bronchitis Clarithromycin tablets are indicated in adults for the treatment of mild to moderate infections caused by susceptible isolates due to Haemophilus influenzae , Haemophilus parainfluenzae , Moraxella catarrhalis , or Streptococcus pneumoniae [see Indications and Usage ( 1.9 )] . 1.2 Acute Maxillary Sinusitis Clarithromycin tablets are indicated for the treatment of mild to moderate infections caused by susceptible isolates due to Haemophilus influenzae , Moraxella catarrhalis , or Streptococcus pneumoniae [see Indications and Usage ( 1.9 )] . 1.3 Community-Acquired Pneumonia Clarithromycin tablets are indicated [see Indications and Usage ( 1.9 )] for the treatment of mild to moderate infections caused by susceptible isolates due to: Haemophilus influenzae (in adults) Mycoplasma pneumoniae, Streptococcus pneumoniae, Chlamydophila pneumoniae (in adults and pediatric patients) 1.4 Pharyngitis/Tonsillitis Clarithromycin tablets are indicated for the treatment of mild to moderate infections caused by susceptible isolates due to Streptococcus pyogenes as an alternative in individuals who cannot use first line therapy. […]
About this medicine
Clarithromycin is a semi-synthetic macrolide antimicrobial for oral use. Chemically, it is 6- 0 ‑ methylerythromycin. The molecular formula is C 38 H 69 NO 13 , and the molecular weight is 747.96. The structural formula is: Clarithromycin is a white to off-white crystalline powder. It is soluble in acetone, slightly soluble in methanol, ethanol, and acetonitrile, and practically insoluble in water. Clarithromycin tablets, USP are intended for oral administration and contain 250 mg or 500 mg of clarithromycin, USP. In addition, each clarithromycin tablet contains the following inactive ingredients: croscarmellose sodium, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, talc, and titanium dioxide. chemicalstructure
How it works
12.1 Mechanism of Action Clarithromycin is a macrolide antimicrobial drug [see Microbiology ( 12.4 )] .
Who should not take it
Hypersensitivity to clarithromycin or any macrolide drug ( 4.1 ) Cisapride and pimozide ( 4.2 ) History of cholestatic jaundice/hepatic dysfunction with use of clarithromycin ( 4.3 ) Colchicine in renal or hepatic impairment ( 4.4 ) Lomitapide, lovastatin, and simvastatin ( 4.5 ) Ergot alkaloids (ergotamine or dihydroergotamine) ( 4.6 ) Lurasidone ( 4.7 ) 4.1 Hypersensitivity Clarithromycin tablets are contraindicated in patients with a known hypersensitivity to clarithromycin, erythromycin, or any of the macrolide antibacterial drugs [see Warnings and Precautions ( 5.1 )] . 4.2 Cisapride and Pimozide Concomitant administration of clarithromycin tablets with cisapride and pimozide is contraindicated [see Drug Interactions ( 7 )] . There have been postmarketing reports of drug interactions when clarithromycin is co‑administered with cisapride or pimozide, resulting in cardiac arrhythmias (QT prolongation, ventricular tachycardia, ventricular fibrillation, and torsades de pointes ) most likely due to inhibition of metabolism of these drugs by clarithromycin tablets. Fatalities have been reported. 4.3 Cholestatic Jaundice/Hepatic Dysfunction Clarithromycin tablets are contraindicated in patients with a history of cholestatic jaundice or hepatic dysfunction associated with prior use of clarithromycin. 4.4 Colchicine Concomitant administration of clarithromycin tablets and colchicine is contraindicated in patients with renal or hepatic impairment. 4.5 Lomitapide, Lovastatin, and Simvastatin Concomitant administration of clarithromycin tablets with lomitapide is contraindicated due to potential for markedly increased transaminases [see Warnings and Precautions ( 5.4 ) and Drug Interactions ( 7 )]. Concomitant administration of clarithromycin tablets with HMG-CoA reductase inhibitors (statins) that are extensively metabolized by CYP3A4 (lovastatin or simvastatin) is contraindicated, due to the increased risk of myopathy, including rhabdomyolysis [see Warnings and Precautions ( 5.4 ) and Drug Interactions ( 7 )]. 4.6 Ergot Alkaloids Concomitant administration of clarithromycin and ergotamine or dihydroergotamine is contraindicated [see Drug Interactions ( 7 )] . […]
Warnings and cautions
Severe Acute Hypersensitivity Reactions : Discontinue clarithromycin tablets if occurs ( 5.1 ) QT Prolongation : Avoid clarithromycin tablets in patients with known QT prolongation or receiving drugs known to prolong the QT interval, ventricular arrhythmia ( torsades de pointes ), hypokalemia/hypomagnesemia, significant bradycardia, or taking Class IA or III antiarrhythmics ( 5.2 ) Hepatotoxicity : Discontinue if signs and symptoms of hepatitis occur ( 5.3 ) Serious adverse reactions can occur due to drug interactions of clarithromycin tablets with colchicine, some lipid-lowering agents, some calcium channel blockers, and other drugs ( 5.4 ) Risk of all-cause mortality one year or more after the end of treatment in patients with coronary artery disease. Balance this potential risk with the treatment benefits when prescribing clarithromycin tablets in these patients ( 5.5 ) Clostridium difficile associated diarrhea (CDAD) : Evaluate if diarrhea occurs ( 5.6 ) Embryo-Fetal Toxicity : Based on animal findings, clarithromycin tablets is not recommended for use in pregnant women except in clinical circumstances where no alternative therapy is appropriate ( 5.7 ) Exacerbation of myasthenia gravis has been reported in patients receiving clarithromycin tablets therapy ( 5.8 ) 5.1 Severe Acute Hypersensitivity Reactions In the event of severe acute hypersensitivity reactions, such as anaphylaxis, Stevens-Johnson Syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS), Henoch-Schonlein purpura, and acute generalized exanthematous pustulosis, discontinue clarithromycin tablets therapy immediately and institute appropriate treatment. 5.2 QT Prolongation Clarithromycin tablets have been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Cases of torsades de pointes have been spontaneously reported during postmarketing surveillance in patients receiving clarithromycin tablets. Fatalities have been reported. […]
Reported side effects
The following serious adverse reactions are described below and elsewhere in the labeling: Acute Hypersensitivity Reactions [see Warnings and Precautions ( 5.1 )] QT Prolongation [see Warnings and Precautions ( 5.2 )] Hepatotoxicity [see Warnings and Precautions ( 5.3 )] Serious Adverse Reactions Due to Concomitant Use with Other Drugs [see Warnings and Precautions ( 5.4 )] Clostridium difficile Associated Diarrhea [see Warnings and Precautions ( 5.6 )] Exacerbation of Myasthenia Gravis [see Warnings and Precautions ( 5.8 )] Most frequent adverse reactions for both adult and pediatric populations in clinical trials: abdominal pain, diarrhea, nausea, vomiting, dysgeusia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sandoz Inc. at 1-800-525-8747 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. Based on pooled data across all indications, the most frequent adverse reactions for both adult and pediatric populations observed in clinical trials are abdominal pain, diarrhea, nausea, vomiting and dysgeusia. Also reported were dyspepsia, liver function test abnormal, anaphylactic reaction, candidiasis, headache, insomnia, and rash. The subsequent subsections list the most common adverse reactions for prophylaxis and treatment of mycobacterial infections and duodenal ulcer associated with H. pylori infection. In general, these profiles are consistent with the pooled data described above. Prophylaxis of Mycobacterial Infections In AIDS patients treated with clarithromycin over long periods of time for prophylaxis against M. avium , it was often difficult to distinguish adverse reactions possibly associated with clarithromycin administration from underlying HIV disease or intercurrent illness. Median duration of treatment was 10.6 months for the clarithromycin group and 8.2 months for the placebo group. Table 4. […]
Interactions with other medicines
Co-administration of clarithromycin tablets is known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug. Clarithromycin tablets should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme. Adjust dosage when appropriate and monitor serum concentrations of drugs primarily metabolized by CYP3A closely in patients concurrently receiving clarithromycin. Table 8. Clinically Significant Drug Interactions with Clarithromycin Tablets Drugs That Are Affected By Clarithromycin Tablets Drug(s) with Pharmacokinetics Affected by Clarithromycin Tablets Recommendation Comments Antiarrhythmics: Disopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine: There have been postmarketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during coadministration of clarithromycin with these drugs [see Warnings and Precautions ( 5.2 )] . Serum concentrations of these medications should also be monitored. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with disopyramide and quinidine. There have been postmarketing reports of hypoglycemia with the concomitant administration of clarithromycin and disopyramide. Therefore, blood glucose levels should be monitored during concomitant administration of clarithromycin and disopyramide. Digoxin Use With Caution Digoxin: Digoxin is a substrate for P-glycoprotein (Pgp) and clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are co‑administered, inhibition of Pgp by clarithromycin may lead to increased exposure of digoxin. […]
Use in specific groups
Geriatric : Increased risk of torsades de pointes ( 8.5 ) 8.1 Pregnancy Risk Summary Based on findings from animal studies, clarithromycin tablets are not recommended for use in pregnant women except in clinical circumstances where no alternative therapy is appropriate. If pregnancy occurs while taking clarithromycin tablets, the patient should be apprised of the potential hazard to the fetus [see Warnings and Precautions ( 5.7 )]. Limited data from a small number of published human studies with clarithromycin tablets use during pregnancy are insufficient to inform drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproduction studies, administration of oral clarithromycin to pregnant mice, rats, rabbits, and monkeys during the period of organogenesis produced malformations in rats (cardiovascular anomalies) and mice (cleft palate) at clinically relevant doses based on body surface area comparison. Fetal effects in mice, rats, and monkeys (e.g., reduced fetal survival, body weight, body weight gain) and implantation losses in rabbits were generally considered to be secondary to maternal toxicity (see Data). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data Animal reproduction studies were conducted in mice, rats, rabbits, and monkeys with oral and intravenously administered clarithromycin. In pregnant mice, clarithromycin was administered during organogenesis (gestation day [GD] 6 to 15) at oral doses of 15, 60, 250, 500, or 1000 mg/kg/day. Reduced body weight observed in dams at 1000 mg/kg/day (3 times the maximum recommended human dose [MRHD] based on body surface area comparison) resulted in reduced survival and body weight of the fetuses. At ≥ 500 mg/kg/day, increases in the incidence of post-implantation loss and cleft palate in the fetuses were observed. […]
If too much is taken
Overdosage of clarithromycin tablets can cause gastrointestinal symptoms such as abdominal pain, vomiting, nausea, and diarrhea. Treat adverse reactions accompanying overdosage by the prompt elimination of unabsorbed drug and supportive measures. As with other macrolides, clarithromycin serum concentrations are not expected to be appreciably affected by hemodialysis or peritoneal dialysis.
Before you take anything new
Tell your pharmacist or doctor about every medicine you take — including ones bought without a prescription, herbal products and supplements. Interactions are one of the most common avoidable causes of harm from medicines, and a pharmacist can check your full list in a couple of minutes.
This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 15 October 2025. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.