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.
Less Frequent Adverse Reactions Observed During Clinical Trials of Clarithromycin
Based on pooled data across all indications, the following adverse reactions were observed in clinical trials with clarithromycin at a rate less than 1%:
Blood and Lymphatic System Disorders:Leukopenia, neutropenia, thrombocythemia, eosinophilia
Cardiac Disorders:Electrocardiogram QT prolonged, cardiac arrest, atrial fibrillation, extrasystoles, palpitations
Ear and Labyrinth Disorders:Vertigo, tinnitus, hearing impaired
Gastrointestinal Disorders:Stomatitis, glossitis, esophagitis, gastrooesophageal reflux disease, gastritis, proctalgia, abdominal distension, constipation, dry mouth, eructation, flatulence
General Disorders and Administration Site Conditions:Malaise, pyrexia, asthenia, chest pain, chills, fatigue
Hepatobiliary Disorders:Cholestasis, hepatitis
Immune System Disorders:Hypersensitivity
Infections and Infestations:Cellulitis, gastroenteritis, infection, vaginal infection
Investigations:Blood bilirubin increased, blood alkaline phosphatase increased, blood lactate dehydrogenase increased, albumin globulin ratio abnormal
Metabolism and Nutrition Disorders:Anorexia, decreased appetite
Musculoskeletal and Connective Tissue Disorders:Myalgia, muscle spasms, nuchal rigidity
Nervous System Disorders:Dizziness, tremor, loss of consciousness, dyskinesia, somnolence
Psychiatric Disorders:Anxiety, nervousness
Renal and Urinary Disorders:Blood creatinine increased, blood urea increased
Respiratory, Thoracic and Mediastinal Disorders:Asthma, epistaxis, pulmonary embolism
Skin and Subcutaneous Tissue Disorders:Urticaria, dermatitis bullous, pruritus, hyperhidrosis, rash maculo-papular
Gastrointestinal Adverse Reactions
In the acute exacerbation of chronic bronchitis and acute maxillary sinusitis studies overall gastrointestinal adverse reactions were reported by a similar proportion of patients taking either clarithromycin tablets or clarithromycin extended-release tablets; however, patients taking clarithromycin extended-release tablets reported significantly less severe gastrointestinal symptoms compared to patients taking clarithromycin tablets. In addition, patients taking clarithromycin extended-release tablets had significantly fewer premature discontinuations for drug-related gastrointestinal or abnormal taste adverse reactions compared to clarithromycin immediate-release tablets.
All-Cause Mortality in Patients with Coronary Artery Disease 1 to 10 Years Following Clarithromycin Exposure
In one clinical trial evaluating treatment with clarithromycin on outcomes in patients with coronary artery disease, an increase in risk of all-cause mortality was observed in patients randomized to clarithromycin. Clarithromycin for treatment of coronary artery disease is not an approved indication. Patients were treated with clarithromycin or placebo for 14 days and observed for primary outcome events (e.g., all-cause mortality or non-fatal cardiac events) for several years.
1A numerically higher number of primary outcome events in patients randomized to receive clarithromycin was observed with a hazard ratio of 1.06 (95% confidence interval 0.98 to 1.14). However, at follow-up 10 years post-treatment, there were 866 (40%) deaths in the clarithromycin group and 815 (37%) deaths in the placebo group that represented a hazard ratio for all-cause mortality of 1.10 (95% confidence interval 1.00 to 1.21). The difference in the number of deaths emerged after one year or more after the end of treatment.
The cause of the difference in all-cause mortality has not been established. Other epidemiologic studies evaluating this risk have shown variable results
[see Warnings and Precautions
(5.5)]
.