What the label lists and what reports show
Clarithromycin side effects
Clarithromycin's FDA label: “The subsequent subsections list the most common adverse reactions for prophylaxis and treatment of mycobacterial infections and duodenal ulcer associated with H. pylori infection.” FAERS holds 34,134 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is nausea (2,292 reports).
- Generic listed
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe subsequent subsections list the most common adverse reactions for prophylaxis and treatment of mycobacterial infections and duodenal ulcer associated with H. pylori infection.
Table 4. Incidence Rates (%) of Selected Adverse Reactions a in Immunocompromised Adult Patients Receiving Prophylaxis Against M. avium Complex
| Body System b | Clarithromycin (n=339) % | Placebo (n=339) % |
|---|---|---|
| Abdominal pain | 5% | 4% |
| Headache | 3% | 1% |
| Diarrhea | 8% | 4% |
| Dyspepsia | 4% | 3% |
| Flatulence | 2% | 1% |
| Nausea | 11% | 7% |
| Vomiting | 6% | 3% |
| Rash | 3% | 4% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe 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 Solaris Pharma Corporation at 1-833-919-0527 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. …
Source: FDA drug label, Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What do FAERS reports show?
34,134 reports list clarithromycin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 2,961 are coded as a death and 13,494 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 14 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Clarithromycin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions