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Biaxin Side Effects

Generic Name: clarithromycin

Note: This page contains information about the side effects of clarithromycin. Some of the dosage forms included on this document may not apply to the brand name Biaxin.

Not all side effects for Biaxin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to clarithromycin: oral powder for suspension, oral tablet, oral tablet extended release

In addition to its needed effects, some unwanted effects may be caused by clarithromycin (the active ingredient contained in Biaxin). In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking clarithromycin:

Less common
  • Cough
  • fever or chills
  • hoarseness
  • lower back or side pain
  • painful or difficult urination
  • Abdominal or stomach tenderness
  • fever with or without chills
  • nausea and vomiting
  • severe abdominal or stomach cramps and pain
  • shortness of breath
  • skin rash and itching
  • unusual bleeding or bruising
  • watery and severe diarrhea, which may also be bloody
  • yellow eyes or skin
Incidence not known
  • Abdominal or stomach pain
  • anxiety
  • black, tarry stools
  • blistering, peeling, or loosening of the skin
  • blurred vision
  • chest pain or discomfort
  • clay-colored stools
  • confusion about identity, place, and time
  • cool, pale skin
  • dark urine
  • depression
  • difficulty with swallowing
  • dizziness
  • fainting
  • fast, pounding, or irregular heartbeat or pulse
  • feeling of unreality
  • feeling that others are watching you or controlling your behavior
  • feeling that others can hear your thoughts
  • feeling, seeing, or hearing things that are not there
  • hives
  • increased hunger
  • irregular heartbeat
  • joint or muscle pain
  • light-colored stools
  • loss of appetite
  • nightmares
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • recurrent fainting
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • redness, swelling, or soreness of the tongue
  • seizures
  • sense of detachment from self or body
  • severe mood or mental changes
  • shakiness
  • slow heartbeat
  • slurred speech
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • sudden death
  • swollen glands
  • tightness in the chest
  • unpleasant breath odor
  • unusual behavior
  • unusual tiredness or weakness
  • vomiting of blood
  • wheezing

Some of the side effects that can occur with clarithromycin may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Less common
  • Acid or sour stomach
  • belching
  • bloated or full feeling
  • change in sensation of taste
  • diarrhea (mild)
  • excess air or gas in the stomach or intestines
  • headache
  • heartburn
  • indigestion
  • passing gas
  • stomach discomfort, upset, or pain
Incidence not known
  • Alterations of sense of smell
  • continuing ringing or buzzing or other unexplained noise in the ears
  • feeling of constant movement of self or surroundings
  • hearing loss
  • lightheadedness
  • mental depression
  • mood or mental changes
  • sensation of spinning
  • shakiness in the legs, arms, hands, or feet
  • skin eruptions
  • sleeplessness
  • sore mouth or tongue
  • swelling or inflammation of the mouth
  • taste loss
  • tongue discoloration
  • tooth discoloration
  • trouble sleeping
  • unable to sleep
  • weight loss

For Healthcare Professionals

Applies to clarithromycin: oral powder for reconstitution, oral tablet, oral tablet extended release


The most common side effects were abdominal pain, diarrhea, nausea, vomiting, and dysgeusia. In community-acquired pneumonia studies, 4% of patients discontinued clarithromycin (the active ingredient contained in Biaxin) due to side effects.[Ref]


Tooth discoloration was usually reversible with professional dental cleaning after the drug was stopped.[Ref]

Very common (10% or more): Nausea (up to 12.3%)
Common (1% to 10%): Diarrhea (up to 7.7%), vomiting (up to 7.5%), abdominal pain (up to 5%), dyspepsia (up to 3.8%), flatulence (up to 2.4%)
Uncommon (0.1% to 1%): Less than 1%: Glossitis, stomatitis, esophagitis, gastroesophageal reflux disease, gastritis, proctalgia, abdominal distension, constipation, dry mouth, eructation, gastroenteritis
Frequency not reported: Oral moniliasis, Clostridium difficile associated diarrhea
Postmarketing reports: Acute pancreatitis, tongue discoloration, tooth discoloration, pseudomembranous colitis[Ref]


Hepatic dysfunction (sometimes severe and usually reversible), including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice have been reported. In some instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications.

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 (the active ingredient contained in Biaxin) therapy is recommended.[Ref]

Common (1% to 10%): Elevated AST/SGOT (greater than 5 times upper limit of normal [ULN]; up to 4%), elevated ALT/SGPT (greater than 5 times ULN; up to 3%), abnormal liver function test (1% or greater)
Uncommon (0.1% to 1%): Less than 1%: Cholestasis, hepatitis (symptoms included anorexia, jaundice, dark urine, pruritus, tender abdomen), increased blood bilirubin, elevated gamma glutamyltransferase, elevated direct bilirubin
Rare (less than 0.1%): Fulminant hepatic failure (at least 1 case)
Frequency not reported: Hepatic dysfunction (including increased liver enzymes), hepatocellular and/or cholestatic hepatitis (with or without jaundice)
Postmarketing reports: Hepatic failure, hepatocellular jaundice, adverse reactions related to hepatic dysfunction[Ref]

Nervous system

Deafness was reported mainly in elderly women and was usually reversible.[Ref]

Very common (10% or more): Dysgeusia/taste perversion (up to 16%)
Common (1% to 10%): Headache (up to 9%)
Uncommon (0.1% to 1%): Less than 1%: Dizziness, loss of consciousness, dyskinesia, somnolence, hearing impaired, tinnitus, tremor, vertigo
Postmarketing reports: Convulsions, ageusia, parosmia, anosmia, paresthesia, deafness[Ref]


Common (1% to 10%): Anaphylactoid reaction (1% or greater)
Uncommon (0.1% to 1%): Less than 1%: Hypersensitivity
Frequency not reported: Allergic reactions
Postmarketing reports: Anaphylactic reaction[Ref]

Allergic reactions have ranged from urticaria and mild skin eruptions to rare cases of anaphylaxis.

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 IV antibiotics were initiated due to persisting fever. She received only one dose of clarithromycin. On day 6 of the hospitalization, the patient was afebrile, IV 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.[Ref]


Uncommon (0.1% to 1%): Less than 1%: Electrocardiogram QT prolonged, cardiac arrest, atrial fibrillation, extrasystoles, palpitations
Rare (less than 0.1%): Arrhythmia
Frequency not reported: QT interval prolongation
Postmarketing reports: Ventricular arrhythmia, ventricular tachycardia, torsades de pointes[Ref]


Common (1% to 10%): Decreased WBC (less than 1 x 10[9]/L; up to 4%), decreased platelet count (less than 50 x 10[9]/L; up to 4%), decreased hemoglobin (less than 8 g/dL; 3%)
Uncommon (0.1% to 1%): Less than 1%: Leukopenia, neutropenia, thrombocythemia, eosinophilia
Postmarketing reports: Thrombocytopenia, agranulocytosis, prolonged prothrombin time, decreased white blood cell count, increased international normalized ratio, hemorrhage[Ref]


Uncommon (0.1% to 1%): Less than 1%: Elevated BUN (greater than 50 mg/dL), elevated serum creatinine, increased blood urea, increased blood creatinine
Frequency not reported: Acute renal failure
Postmarketing reports: Interstitial nephritis, renal failure[Ref]


Common (1% to 10%): Rash (3.2%)
Uncommon (0.1% to 1%): Less than 1%: Urticaria, dermatitis bullous, pruritus, hyperhidrosis, maculopapular rash, cellulitis
Postmarketing reports: Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS), Henoch-Schonlein purpura, acne[Ref]


Many reports of Biaxin(R) XL tablets in the stool occurred in patients with anatomic (including ileostomy or colostomy) or functional gastrointestinal disorders with shortened gastrointestinal transit times. In several reports, tablet residues occurred in the context of diarrhea.

Colchicine toxicity has been reported with concomitant use of clarithromycin (the active ingredient contained in Biaxin) and colchicine, especially in the elderly; some occurred in patients with renal dysfunction. Death occurred in some such patients.[Ref]

Common (1% to 10%): Infection (2%), candidiasis (1% or greater)
Uncommon (0.1% to 1%): Less than 1%: Malaise, pyrexia, asthenia, chest pain, chills, fatigue, abnormal albumin globulin ratio
Postmarketing reports: Biaxin(R) XL tablets in the stool, colchicine toxicity[Ref]


Psychotic disorder, confusional state, depersonalization, depression, disorientation, manic behavior, hallucination, abnormal behavior, and/or abnormal dreams usually resolved after the drug was stopped.[Ref]

Common (1% to 10%): Insomnia (1% or greater)
Uncommon (0.1% to 1%): Less than 1%: Anxiety, nervousness
Frequency not reported: Behavioral changes, nightmares, psychosis
Postmarketing reports: Psychotic disorder, confusional state, depersonalization, disorientation, hallucination, depression, manic behavior, abnormal behavior, abnormal dreams[Ref]


Hypoglycemia has been reported in patients receiving oral hypoglycemic agents or insulin.[Ref]

Common (1% to 10%): Increased alkaline phosphatase (greater than 5 times ULN; up to 2%)
Uncommon (0.1% to 1%): Less than 1%: Anorexia, decreased appetite, increased blood alkaline phosphatase, increased blood lactate dehydrogenase
Postmarketing reports: Hypoglycemia[Ref]


In some cases of rhabdomyolysis, clarithromycin (the active ingredient contained in Biaxin) was coadministered with statins, fibrates, colchicine, or allopurinol.

Uncommon (0.1% to 1%): Less than 1%: Myalgia, muscle spasms, nuchal rigidity
Frequency not reported: New onset of symptoms of myasthenic syndrome, exacerbation of symptoms of myasthenia gravis
Postmarketing reports: Myopathy, rhabdomyolysis


Uncommon (0.1% to 1%): Less than 1%: Asthma, epistaxis, pulmonary embolism
Frequency not reported: Laryngismus[Ref]


Rare (less than 0.1%): Corneal opacities (at least 1 case)[Ref]

A case of corneal opacities was reported in a patient with AIDS and Mycobacterium avium complex bacteremia. The patient's ocular signs and symptoms resolved upon substitution with azithromycin.[Ref]


Rare (less than 0.1%): Leukocytoclastic vasculitis[Ref]


Uncommon (0.1% to 1%): Less than 1%: Vaginal infection
Postmarketing reports: Abnormal urine color (associated with hepatic failure)[Ref]


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