Clarithromycin Side Effects 

Side Effects of Clarithromycin  

Clarithromycin

All medicines  may cause side effects, but many people have no, or minor, side  effects. Check with  your doctor if any of these most COMMON side effects persist  or become bothersome when using Clarithromycin: 

Abnormal taste; diarrhea; headache; indigestion; nausea; stomach discomfort; vomiting. 

Seek medical attention right away if any of these SEVERE side effects occur when using Clarithromycin: 

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools; confusion; decreased urination; depression; emotional or mood changes; hallucinations; nightmares; severe diarrhea; severe stomach pain/cramps; trouble sleeping. 

Clarithromycin Extended-Release Tablets 

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Clarithromycin Extended-Release Tablets: 

Abnormal taste; diarrhea; headache; indigestion; nausea; stomach discomfort; vomiting. 

Seek medical attention right away if any of these SEVERE side effects occur when using Clarithromycin Extended-Release Tablets: 

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools; confusion; decreased urination; depression; emotional or mood changes; hallucinations; nightmares; severe diarrhea; severe  stomach pain/cramps; trouble sleeping. 

Clarithromycin Suspension 

All medicines may cause side effects, but many people have no, or minor, side effects. Check with  your doctor if any of these most COMMON side effects persist or become bothersome when using Clarithromycin Suspension: 

Abnormal taste; diarrhea; headache; indigestion; nausea; stomach discomfort; vomiting. 

Seek medical attention right away if any of these SEVERE side effects occur when using Clarithromycin Suspension: 

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools; confusion; decreased urination; depression; emotional or mood changes; hallucinations; nightmares; severe diarrhea; severe stomach pain/cramps; trouble sleeping. 

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA 

Side Effects by Body System 

General
Clarithromycin is generally well tolerated. In large studies, 3% to 4% of patients discontinued clarithromycin therapy due to adverse side effects. 

Gastrointestinal
Gastrointestinal side effects are the most common side effects of clarithromycin and include abdominal discomfort, dyspepsia, nausea, and diarrhea in 2% to 3% of patients. Anorexia and vomiting have been reported in postmarketing studies. 

Nervous system 
Nervous system side effects are unusual. An alteration in taste may occur in 1% to 2%  of patients during clarithromycin therapy. Headache, depression, and dizziness have been reported rarely. Myasthenic syndrome has been described in an isolated case report. 

Hepatic
Clarithromycin-induced hepatotoxicity is rare and typically associated with higher dosages (1 to 2 grams/day) and high serum drug concentrations. The enzyme elevation pattern is usually cholestatic with minimal elevations of SGOT and SGPT. 

In patients with liver disease, frequent monitoring of liver function test during prolonged clarithromycin therapy is recommended. 

Hepatic side effects have included mild increases in liver function tests and hepatocellular and/or cholestatic hepatitis. Fulminant hepatic failure has been reported in at least one patient during clarithromycin treatment. Pancreatitis has also been reported. 

Hypersensitivity
Hypersensitivity reactions including rash have been reported  in 1% to 2% of patients. Postmarketing studies have reported allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis. 

A 92-year-old female admitted for heart failure and a  right upper lobe infiltrate was started on clarithromycin 500 mg. The following day, the clarithromycin was discontinued and intravenous antibiotics were initiated due to persisting fever. She received only one dose of clarithromycin. On day 6  of the hospitalization, the patient was afebrile, intravenous antibiotics were stopped, and clarithromycin was again started. Two hours following the dose, the patient developed swelling in her lips, jaw, tongue, mouth, and face. The patient was given diphenhydramine and the clarithromycin was discontinued. She was discharged the following day. 

Ocular
A single case  of corneal opacities has been associated with the use of clarithromycin in a patient with AIDS and M. avium complex bacteremia. The patient's ocular signs and symptoms resolved upon substitution with azithromycin. 

Psychiatric
Psychiatric side effects have been reported in postmarketing experience and include anxiety, behavioral changes, confusional states, depersonalization, disorientation, hallucinations, insomnia, manic behavior, nightmares, psychosis, tinnitus, tremor, and vertigo. These effects usually resolve after discontinuation of clarithromycin. 

Immunologic
Immunologic side effects have been extremely rare and include isolated cases of leukocytoclastic vasculitis. 

Cardiovascular 
Cardiovascular side effects including QT interval prolongation, ventricular tachycardia, and torsade de pointes have been reported rarely. 

Renal
Renal  side effects reported in postmarketing studies  have included elevated BUN (4%), elevated serum creatinine (less than 1%), and acute renal failure. 

Other
Other  side effects reported in postmarketing study have included laryngismus, glossitis, stomatitis, oral moniliasis, tongue and tooth discoloration, reversible hearing loss, and alterations of  the sense of smell. 

The hearing loss that has been reported was usually reversible  and occurred mainly in elderly women. 

Hematologic
Hematologic side effects include decreased WBC (< 1%) and elevated prothrombin time (1%). Thrombocytopenia, leukopenia, and neutropenia have also been reported in postmarketing studies. 

Endocrine 
Endocrine side effects are extremely rare. Hypoglycemia has been reported in postmarketing studies; however, some cases occurred in patients receiving oral hypoglycemic agents or insulin.