Biaxin, known generically as clarithromycin, is a macrolide antibiotic prescribed for the treatment of a wide range of bacterial infections. It functions by inhibiting bacterial protein synthesis, effectively stopping the growth and spread of susceptible bacteria. This medication is commonly used for respiratory tract infections, skin infections, and Helicobacter pylori eradication in combination therapy. Its well-established pharmacokinetic profile ensures reliable systemic absorption and tissue penetration, making it a trusted choice for clinicians in both outpatient and inpatient settings.

Features

• Active pharmaceutical ingredient: Clarithromycin
• Available in oral formulations: tablets (250 mg, 500 mg) and granules for suspension
• Belongs to the macrolide class of antibiotics
• Demonstrated efficacy against a broad spectrum of aerobic and anaerobic Gram-positive and Gram-negative bacteria
• Some formulations are extended-release (Biaxin XL) for once-daily dosing
• Typically supplied in blister packs or bottles with patient information leaflets

Benefits

• Effectively treats common bacterial infections such as pneumonia, bronchitis, and sinusitis
• Plays a key role in combination therapy for eradicating H. pylori, reducing the risk of peptic ulcer recurrence
• Offers convenient dosing schedules that support patient adherence to treatment regimens
• Provides reliable bacteriostatic action with a well-understood resistance profile
• Available in multiple formulations to suit different patient populations, including pediatric suspensions
• Supported by extensive clinical data and decades of real-world use confirming its efficacy and safety

Common use

Biaxin (clarithromycin) is indicated for the treatment of mild to moderate infections caused by susceptible strains of designated microorganisms. Its primary uses include acute bacterial exacerbation of chronic bronchitis due to Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, or Streptococcus pneumoniae; acute maxillary sinusitis due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae; community-acquired pneumonia due to Mycoplasma pneumoniae, Streptococcus pneumoniae, or Chlamydophila pneumoniae; pharyngitis/tonsillitis due to Streptococcus pyogenes; and uncomplicated skin and skin structure infections due to Staphylococcus aureus or Streptococcus pyogenes. Furthermore, it is a critical component of combination regimens for the eradication of Helicobacter pylori to reduce the risk of duodenal ulcer recurrence, used alongside a proton pump inhibitor and sometimes other antibiotics like amoxicillin or metronidazole. Off-label uses may include, under specialist guidance, the treatment or prophylaxis of certain atypical mycobacterial infections, particularly in immunocompromised patients.

Dosage and direction

Dosage of Biaxin must be individualized based on the type and severity of the infection, renal function, and the specific formulation prescribed. For most infections in adults, the usual dose is 250 mg to 500 mg orally every 12 hours for 7 to 14 days. For H. pylori eradication, a typical triple therapy regimen includes Biaxin 500 mg, amoxicillin 1000 mg, and a proton pump inhibitor (e.g., lansoprazole 30 mg), all taken twice daily for 14 days. The extended-release tablets (Biaxin XL) are dosed as 1000 mg (two 500 mg tablets) once daily with food for 7 to 14 days depending on the infection. For pediatric patients, the dosage is based on body weight, typically 7.5 mg/kg twice daily, not to exceed adult doses. All doses should be taken at evenly spaced intervals to maintain constant blood levels, with or without food as directed (though administration with food may minimize gastrointestinal upset). The full prescribed course must be completed even if symptoms improve earlier to prevent antibiotic resistance. Dosage adjustment is necessary in patients with severe renal impairment (creatinine clearance less than 30 mL/min).

Precautions

Prior to initiating therapy with Biaxin, a thorough medical history should be obtained. Use with caution in patients with known hypersensitivity to other macrolide antibiotics. Caution is advised in patients with hepatic impairment; periodic liver function tests may be warranted during prolonged therapy. Biaxin should be used cautiously in patients with existing cardiac conditions, particularly those with known QT prolongation, arrhythmias, or electrolyte imbalances, due to a potential risk of QT interval prolongation and subsequent cardiac arrhythmias. Patients with myasthenia gravis may experience exacerbation of symptoms, including muscle weakness and respiratory distress. Prolonged or repeated use may result in bacterial or fungal superinfection, including Clostridioides difficile-associated diarrhea. Patients should be advised to report any signs of allergic reactions, persistent diarrhea, or unusual heart rhythms immediately.

Contraindications

Biaxin is contraindicated in patients with known hypersensitivity to clarithromycin, any other macrolide antibiotic, or any component of the formulation. Concomitant administration with cisapride, pimozide, astemizole, terfenadine, ergotamine, or dihydroergotamine is contraindicated due to the risk of serious and potentially fatal cardiac arrhythmias, such as torsades de pointes. It is also contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior clarithromycin use. Use is contraindicated in patients receiving colchicine who have renal or hepatic impairment.

Possible side effect

Like all medications, Biaxin can cause side effects, although not everybody gets them. Common side effects (affecting more than 1 in 10 people) include diarrhea, nausea, abdominal pain, and abnormal taste sensation (dysgeusia). Uncommon side effects (affecting between 1 in 100 and 1 in 1000 people) may include headache, indigestion, vomiting, and reversible hearing loss (usually with high doses or renal impairment). Rare but serious side effects require immediate medical attention and include severe allergic reactions (rash, hives, itching, difficulty breathing, swelling of the face, lips, or tongue), severe or persistent diarrhea (which may be a sign of C. difficile colitis), symptoms of liver problems (persistent nausea, vomiting, loss of appetite, dark urine, jaundice), irregular heartbeat, palpitations, and severe skin reactions (e.g., Stevens-Johnson syndrome).

Drug interaction

Biaxin is a potent inhibitor of the cytochrome P450 enzyme system (particularly CYP3A4) and has the potential for significant drug interactions. Concomitant use with the following drugs is contraindicated or requires extreme caution and possible dosage adjustment: Cisapride, pimozide, astemizole, terfenadine (risk of QT prolongation and torsades de pointes); Ergotamine and dihydroergotamine (risk of ergotism); Colchicine (increased risk of colchicine toxicity, especially in patients with renal/hepatic impairment); HMG-CoA reductase inhibitors (statins) like lovastatin and simvastatin (increased risk of myopathy/rhabdomyolysis); Oral anticoagulants like warfarin (increased anticoagulant effect, requiring close INR monitoring); Many antiretroviral drugs for HIV (e.g., ritonavir, saquinavir) and certain immunosuppressants (e.g., cyclosporine, tacrolimus) require careful therapeutic drug monitoring due to increased serum concentrations. Patients should provide their doctor with a complete list of all medications, including over-the-counter drugs and herbal supplements, before starting Biaxin.

Missed dose

If a dose of Biaxin is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not take a double dose to make up for the missed one, as this increases the risk of side effects. Maintaining a consistent level of the antibiotic in the body is important for efficacy, so patients should try to adhere strictly to the prescribed schedule. Using pill organizers or setting alarms can be helpful strategies to improve adherence.

Overdose

In the event of a suspected overdose, medical attention should be sought immediately. Symptoms of Biaxin overdose are typically an extension of its known adverse effects and may include severe nausea, vomiting, diarrhea, abdominal pain, and pronounced changes in taste. In severe cases, reversible hearing loss, hepatic toxicity, and QT prolongation leading to arrhythmias may occur. Management is supportive and symptomatic. There is no specific antidote for clarithromycin overdose. Gastric lavage may be considered if presented soon after ingestion. Due to the potential for serious cardiac effects, ECG monitoring is recommended in cases of significant overdose.

Storage

Biaxin tablets should be stored at room temperature (15°C to 30°C or 59°F to 86°F) in their original container, protected from light and moisture. Keep the bottle tightly closed and away from excess heat and damp places (like bathrooms). The oral suspension, once reconstituted with water by the pharmacist, should be stored in a refrigerator (2°C to 8°C or 36°F to 46°F) and discarded after 14 days. Do not freeze the suspension. All medications must be kept out of the reach of children and pets. Do not use beyond the expiration date printed on the packaging.

Disclaimer

This information is intended for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The content provided is based on the manufacturer’s prescribing information but may not encompass all possible uses, directions, precautions, or interactions. The author and publisher are not responsible for any specific health or allergy needs that may require medical supervision or for any adverse effects resulting from the use of information contained herein.

Reviews

Clinical studies and post-marketing surveillance over decades have established Biaxin (clarithromycin) as a generally well-tolerated and effective antibiotic for its approved indications. In clinical trials for respiratory tract infections, it demonstrated clinical success rates comparable to other first-line antibiotics. Its role in H. pylori eradication therapy is well-supported by meta-analyses, showing high efficacy in combination regimens. Patient-reported outcomes often note the convenience of the twice-daily dosing, though the common side effect of dysgeusia (metallic taste) is frequently mentioned. As with all antibiotics, the emergence of bacterial resistance is an ongoing concern, underscoring the importance of appropriate use based on culture and susceptibility testing when possible. Overall, it remains a valuable tool in the antimicrobial arsenal for trained medical professionals.