Clarithromycin side effects

List of side effects
Observed in clinical trials Post-marketing experience Changes in lab values
 * Most frequent (BIAXIN tablets)
 * Most frequent (BIAXIN XL)
 * Chronic bronchitis/acute maxillary sinusitis
 * Community-acquired pneumonia
 * Acute otitis media
 * Transient CNS events
 * Hepatic dysfunction
 * Hypoglycemia
 * BIAXIN XL tablets in the stool
 * QT prolongation/ventricular arrhythmias
 * Interstitial nephritis
 * Colchicine toxicity

Observed in clinical trials
The majority of side effects observed in clinical trials were of a mild and transient nature. Fewer than 3% of adult patients without mycobacterial infections and fewer than 2% of pediatric patients without mycobacterial infections discontinued therapy because of drug-related side effects. Fewer than 2% of adult patients taking BIAXIN XL tablets discontinued therapy because of drug-related side effects. Return to top

Most frequent (BIAXIN tablets)
The most frequently reported events in adults taking BIAXIN tablets (clarithromycin tablets, USP) were diarrhea (3%), nausea (3%), abnormal taste (3%), dyspepsia (2%), abdominal pain/discomfort (2%), and headache (2%). In pediatric patients, the most frequently reported events were diarrhea (6%), vomiting (6%), abdominal pain (3%), rash (3%), and headache (2%). Most of these events were described as mild or moderate in severity. Of the reported adverse events, only 1% was described as severe. Return to top

Most frequent (BIAXIN XL)
The most frequently reported events in adults taking BIAXIN XL (Clarithromycin extended-release tablets) were diarrhea (6%), abnormal taste (7%), and nausea (3%). Most of these events were described as mild or moderate in severity. Of the reported adverse events, less than 1% were described as severe. Return to top

Chronic bronchitis/acute maxillary sinusitis
In the acute exacerbation of chronic bronchitis and acute maxillary sinusitis studies overall gastrointestinal adverse events were reported by a similar proportion of patients taking either BIAXIN tablets or BIAXIN XL tablets; however, patients taking BIAXIN XL tablets reported significantly less severe gastrointestinal symptoms compared to patients taking BIAXIN tablets. In addition, patients taking BIAXIN XL tablets had significantly fewer premature discontinuations for drug related gastrointestinal or abnormal taste adverse events compared to BIAXIN tablets. Return to top

Community-acquired pneumonia
In community-acquired pneumonia studies conducted in adults comparing clarithromycin to erythromycin base or erythromycin stearate, there were fewer adverse events involving the digestive system in clarithromycin-treated patients compared to erythromycin-treated patients (13% vs 32%; p < 0.01). Twenty percent of erythromycin-treated patients discontinued therapy due to adverse events compared to 4% of clarithromycin-treated patients. Return to top

Acute otitis media
In two U.S. studies of acute otitis media comparing Clarithromycin to amoxicillin/potassium clavulanate in pediatric patients, there were fewer adverse events involving the digestive system in Clarithromycin-treated patients compared to amoxicillin/potassium clavulanate-treated patients (21% vs 40%, p<0.001). One-third as many Clarithromycin-treated patients reported diarrhea as did amoxicillin/potassium clavulanate-treated patients. Return to top

Post-marketing experience
Allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis have occurred. Other spontaneously reported adverse events include glossitis, stomatitis, oral moniliasis, anorexia, vomiting, pancreatitis, tongue discoloration, thrombocytopenia, leukopenia, neutropenia, and dizziness. There have been reports of tooth discoloration in patients treated with Clarithromycin. Tooth discoloration is usually reversible with professional dental cleaning. There have been isolated reports of hearing loss, which is usually reversible, occurring chiefly in elderly women. Reports of alterations of the sense of smell, usually in conjunction with taste perversion or taste loss have also been reported. Return to top

Transient CNS events
Transient CNS events including anxiety, behavioral changes, confusional states, convulsions, depersonalization, disorientation, hallucinations, insomnia, manic behavior, nightmares, psychosis, tinnitus, tremor, and vertigo have been reported during post-marketing surveillance. Events usually resolve with discontinuation of the drug. Return to top

Hepatic dysfunction
Hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been infrequently reported with Clarithromycin. This hepatic dysfunction may be severe and is usually reversible. In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications. Return to top

Hypoglycemia
There have been rare reports of hypoglycemia, some of which have occurred in patients taking oral hypoglycemic agents or insulin. Return to top

BIAXIN XL tablets in the stool
There have been post-marketing reports of BIAXIN XL tablets in the stool, many of which have occurred in patients with anatomic (including ileostomy or colostomy) or functional gastrointestinal disorders with shortened GI transit times. Return to top

QT prolongation/ventricular arrhythmias
As with other macrolides, Clarithromycin has been associated with QT prolongation and ventricular arrhythmias, including ventricular tachycardia and torsades de pointes. Return to top

Interstitial nephritis
There have been reports of interstitial nephritis coincident with Clarithromycin use. Return to top

Colchicine toxicity
There have been post-marketing reports of colchicine toxicity with concomitant use of Clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients. Return to top

Changes in lab values
Changes in laboratory values with possible clinical significance were as follows: GGT, alkaline phosphatase, and prothrombin time data are from adult studies only. Return to top
 * Hepatic elevated SGPT (ALT) < 1%; SGOT (AST) < 1%; GGT < 1%; alkaline phosphatase < 1%; LDH < 1%; total bilirubin < 1%
 * Hematologic decreased WBC < 1%; elevated prothrombin time 1%
 * Renal elevated BUN 4%; elevated serum creatinine < 1%