Biaxin: Uses, dosage, side effects, warnings & patient reviews

What is Biaxin (Clarithromycin)?

Biaxin is the brand name for the antibiotic drug clarithromycin. It belongs to the macrolide class of antibiotics. Clarithromycin works by inhibiting bacterial protein synthesis, which stops the growth of susceptible bacteria.

The medication is available in immediate-release tablets (e.g., Biaxin 500 mg), extended-release tablets (Biaxin XL), and oral suspension. Biaxin XL is designed for once-daily dosing. As a prescription medication, it should only be used under the supervision of a healthcare professional who has confirmed a bacterial infection.

Biaxin is metabolized in the liver into an active compound, 14-hydroxyclarithromycin. It is a potent inhibitor of the cytochrome P450 3A4 (CYP3A4) enzyme system, which is the basis for many of its significant drug interactions.

How to Take Biaxin

Administration instructions must be followed precisely as directed by the prescribing physician. Do not adjust the dosage or stop treatment without medical advice.

Administration Guidelines

Biaxin tablets should be swallowed whole with a full glass of water. They can be taken with or without food. Taking the medication with food may improve tolerability if stomach upset occurs.

The oral suspension must be shaken well before each use. A calibrated measuring device should be used to ensure an accurate dose; household spoons are not appropriate.

Course Completion and Resistance

It is critical to complete the entire prescribed course of Biaxin, even if symptoms improve before the medication is finished. Stopping antibiotics early can lead to incomplete eradication of the infection and contribute to antibiotic resistance.

Missed Dose

If a dose is missed, it should be taken as soon as it is remembered. If it is close to the time of the next scheduled dose, the missed dose should be skipped. Doubling a dose to make up for a missed one is not recommended.

Side Effects of Biaxin

As with all antibiotics, Biaxin can cause adverse effects. The following list is not exhaustive, and any new or worsening symptoms should be reported to a healthcare provider.

What is Biaxin Used For?

Biaxin (clarithromycin) is indicated for the treatment of mild to moderate infections caused by susceptible strains of designated bacteria.

FDA-Approved Uses

• Respiratory Tract Infections: Including community-acquired pneumonia, acute exacerbation of chronic bronchitis due to bacteria, acute maxillary sinusitis, and pharyngitis/tonsillitis.
• Skin and Skin Structure Infections: Uncomplicated infections such as folliculitis, cellulitis, and erysipelas.
• Helicobacter pylori Eradication: Biaxin is used in combination with other medications (e.g., amoxicillin and a proton pump inhibitor) for the treatment of patients with H. pylori infection and duodenal ulcer disease. This is to eradicate H. pylori and reduce the risk of ulcer recurrence. More details are available on H. pylori eradication therapy.

Important Limitations

Biaxin is effective only against bacterial infections. It is not active against viral infections such as the common cold or influenza. Inappropriate use for viral infections contributes to antibiotic resistance.

Important Safety Concerns and Considerations

Cardiovascular Risks: QT Prolongation

Clarithromycin has been associated with prolongation of the QT interval on the electrocardiogram. This effect can lead to an increased risk of ventricular arrhythmias, including torsades de pointes, which can be fatal. The risk is higher in patients with:

• Pre-existing cardiac conditions (see heart disease).
• Electrolyte disturbances (e.g., low potassium or magnesium).
• Concurrent use of other drugs known to prolong the QT interval.
• A history of arrhythmias.

Patients should report symptoms such as palpitations, dizziness, or syncope immediately.

Exacerbation of Myasthenia Gravis

Macrolide antibiotics, including clarithromycin, have been associated with exacerbations of symptoms (including respiratory failure) in patients with myasthenia gravis. Its use in this population is generally avoided unless no other therapeutic alternatives are available.

Clostridioides difficile-Associated Diarrhea (CDAD)

Antibiotic use, including with Biaxin, can disrupt the normal flora of the colon and may permit overgrowth of C. difficile, a toxin-producing bacterium. This can range from mild diarrhea to life-threatening colitis. CDAD can occur even months after antibiotic treatment has concluded.

Hepatotoxicity

Severe liver toxicity, including hepatitis and hepatic failure, has been reported with clarithromycin, usually in association with serious underlying diseases and/or concomitant medications. Liver function tests may be monitored in patients with pre-existing liver disease.

Critical Warnings for Biaxin Use

Drug Interaction Warnings

Biaxin is contraindicated with several drug classes due to the risk of severe toxicity or life-threatening reactions. These include, but are not limited to:

• Colchicine: Contraindicated in patients with renal or hepatic impairment due to risk of colchicine toxicity.
• HMG-CoA Reductase Inhibitors (Statins): Contraindicated with simvastatin and lovastatin due to high risk of rhabdomyolysis. Use with other statins requires caution.
• Ergot Alkaloids: Contraindicated due to risk of acute ergot toxicity (severe peripheral vasospasm).
• Pimozide: Contraindicated due to risk of cardiac arrhythmias.

A thorough medication history is essential prior to prescription.

Mortality in Patients with Coronary Artery Disease

One large, long-term clinical study in patients with coronary artery disease observed an increase in all-cause mortality among those treated with a two-week course of clarithromycin compared to placebo. The underlying mechanism is unknown. This observation should be considered when prescribing clarithromycin to patients with known cardiovascular disease.

Renal Impairment

Dosage adjustment is recommended for patients with severe renal impairment (creatinine clearance less than 30 mL/min). In these patients, the recommended dose of clarithromycin is reduced by 50%, or the dosing interval is doubled. The extended-release formulation (Biaxin XL) should not be used in patients with renal impairment.

Biaxin Dosage Information

Dosage is determined by the treating physician based on the type and severity of infection, renal function, and patient factors. The following table provides general guidelines for adults with normal renal function; always follow the specific prescription.

*PPI: Proton Pump Inhibitor (e.g., omeprazole, lansoprazole). The specific regimen is determined by the physician.

Biaxin XL (Extended-Release)

The Biaxin XL formulation is dosed as 1000 mg (two 500 mg tablets) once daily with food for 7 to 14 days, depending on the infection. It is indicated for acute maxillary sinusitis, community-acquired pneumonia, and acute exacerbation of chronic bronchitis.

Important Administration Notes

• Renal Impairment: Dosage must be reduced in patients with severe renal impairment (CrCl < 30 mL/min).
• Hepatic Impairment: Use with caution in patients with hepatic impairment. Dosage adjustment may be necessary.
• Pediatric Dosing: For children, dosing is based on body weight (typically 7.5 mg/kg every 12 hours). The maximum daily dose should not exceed adult doses.

Drug Interactions with Biaxin

Clarithromycin is a strong inhibitor of the CYP3A4 enzyme and has a high potential for clinically significant drug interactions. This list is not exhaustive. Inform your doctor of all medications you take, including prescription, over-the-counter, and herbal products.

Additional Information

Storage and Handling

Store Biaxin tablets and oral suspension at room temperature (between 15°C and 30°C or 59°F and 86°F), in a tightly closed container, away from light and moisture. Do not store the suspension in the refrigerator. Keep all medications out of the reach of children and pets. Discard any unused oral suspension after the timeframe specified on the label (usually 14 days after mixing).

Cost and Generic Availability

Generic clarithromycin is widely available and is typically less expensive than the brand-name Biaxin. Generic medications contain the same active ingredient and are required to meet the same standards for safety, quality, and efficacy. The “Biaxin price” can vary between pharmacies and insurance plans.

Obtaining Medication Safely

Biaxin is a prescription-only medication. It should only be obtained with a valid prescription from a licensed healthcare provider. Patients should be cautious of online sources offering to sell prescription medications without a prescription, as these may provide counterfeit or substandard products.

Reporting Side Effects

Patients and healthcare providers are encouraged to report negative side effects of prescription drugs to the relevant national health authority (e.g., the FDA in the United States). Reporting contributes to ongoing drug safety monitoring.

References and Medical Sources

The information on this page is compiled from reputable medical sources and prescribing information.

1. U.S. Food and Drug Administration (FDA). Biaxin (clarithromycin) Prescribing Information. [Updated 2018]. https://www.accessdata.fda.gov/drugsatfda_docs/label/2009/050662s042,050698s024,050775s013lbl.pdf
2. MedlinePlus. Clarithromycin. U.S. National Library of Medicine; [Updated 2022]. https://medlineplus.gov/druginfo/meds/a692005.html
3. Drugs.com. Clarithromycin Professional Monograph. Drugs.com; [Updated 2024]. https://www.drugs.com/monograph/clarithromycin.html
4. Pichichero, M. E. (2011). Macrolides. In J. E. Bennett, R. Dolin, & M. J. Blaser (Eds.), Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases (7th ed.). Churchill Livingstone.

Disclaimer: The information on this site is provided for informational purposes only and is not medical advice. It does not replace professional medical consultation, diagnosis, or treatment. Do not self-medicate based on the information presented on this site. Always consult with a doctor or other qualified healthcare professional before making any decisions about your health.