Clarithromycin is a prescription macrolide antibiotic used to treat a range of bacterial infections including pneumonia, bronchitis, sinusitis, strep throat, and stomach ulcers caused by H. pylori.

What Is Clarithromycin?

Clarithromycin is the generic name for the antibiotic originally sold under the brand name Biaxin (and Biaxin XL for the extended-release version). It belongs to the macrolide class of antibiotics, which also includes Azithromycin (Zithromax) and Erythromycin.

Clarithromycin was originally manufactured by AbbVie (formerly Abbott Laboratories) and received FDA approval in the 1990s. Today, the brand-name version is largely discontinued, and Clarithromycin is widely available as an affordable generic made by manufacturers including Teva, Sandoz, Sun Pharma, and Aurobindo.

Clarithromycin is not a controlled substance — it has no DEA scheduling and no risk of addiction or abuse.

What Is Clarithromycin Used For?

Clarithromycin is FDA-approved for treating several types of bacterial infections:

• Community-acquired pneumonia (CAP) — A common lung infection picked up outside of hospitals
• Acute bacterial exacerbation of chronic bronchitis — When chronic bronchitis flares up due to a bacterial infection
• Acute maxillary sinusitis — Bacterial sinus infection
• Pharyngitis/tonsillitis (strep throat) — Especially in patients allergic to Penicillin
• Uncomplicated skin and skin structure infections — Bacterial skin infections like cellulitis
• Acute otitis media — Middle ear infections in children
• H. pylori eradication — Used in combination with other medications (like Amoxicillin and a proton pump inhibitor) to treat stomach ulcers caused by Helicobacter pylori
• Mycobacterium avium complex (MAC) disease — Prevention and treatment in patients with HIV/AIDS

Doctors also prescribe Clarithromycin off-label for conditions like Lyme disease, Legionnaires' disease, whooping cough, cat scratch disease, and dental infections.

How Is Clarithromycin Taken?

Clarithromycin comes in three formulations:

• Immediate-release tablets — 250 mg and 500 mg. Taken twice daily, with or without food.
• Extended-release tablets (Biaxin XL) — 500 mg. Taken once daily, must be taken with food. Do not crush, chew, or break these tablets.
• Oral suspension — 125 mg/5 mL and 250 mg/5 mL. Designed for children who can't swallow tablets.

Typical Dosing

• Adults: 250 mg to 500 mg twice daily (immediate-release) or 1,000 mg once daily (extended-release)
• Children: 7.5 mg/kg twice daily, up to a maximum of 500 mg twice daily
• Treatment duration: Usually 7 to 14 days, depending on the infection. H. pylori regimens typically last 10 to 14 days.

Always take the full course your doctor prescribes, even if you start feeling better before it's done. Stopping early can lead to antibiotic resistance. Learn more about how Clarithromycin works.

Who Should Not Take Clarithromycin?

Clarithromycin is not safe for everyone. You should not take it if you:

• Have a known allergy to Clarithromycin, Erythromycin, or any macrolide or ketolide antibiotic
• Have a history of jaundice or liver problems caused by a previous course of Clarithromycin
• Take Cisapride, Pimozide, Ergotamine, Dihydroergotamine, Lovastatin, Simvastatin, or Lomitapide — these are contraindicated drug combinations
• Have a history of QT prolongation or ventricular heart arrhythmias

Special Populations

• Pregnancy: Category C — animal studies showed adverse effects. Only use if the benefit clearly outweighs the risk. Talk to your OB-GYN.
• Breastfeeding: Clarithromycin passes into breast milk. Use with caution.
• Children under 6 months: Not approved for use.
• Kidney impairment: Dose adjustment needed if creatinine clearance is below 30 mL/min.
• Liver impairment: Use with caution; increased risk of toxicity.
• Heart disease: The FDA warned in 2018 about increased cardiac risks. Your doctor may choose a different antibiotic.

Be sure to review all potential side effects of Clarithromycin before starting treatment.

How Much Does Clarithromycin Cost?

Clarithromycin is available as a generic, which makes it much more affordable than the original brand-name Biaxin:

• With a discount coupon: As low as $14-$24 for 14 tablets of generic Clarithromycin 500 mg
• Retail cash price (no coupon): Approximately $148 for 28 tablets of 500 mg
• Extended-release version: $52-$243 for 14 tablets, depending on the pharmacy
• With insurance: Typically $0-$20 copay. Generic Clarithromycin is on most formularies as a Tier 1 or Tier 2 drug.

Prices vary significantly between pharmacies, so it pays to shop around. Check our full guide on how to save money on Clarithromycin, including coupon cards, patient assistance programs, and the cheapest pharmacies.

If you need help finding Clarithromycin at a pharmacy near you, Medfinder can help you check stock and compare prices.

Final Thoughts

Clarithromycin is a well-established, effective antibiotic that's been used for decades to treat common bacterial infections. It's widely available as an affordable generic, covered by most insurance plans, and can be prescribed by primary care doctors, urgent care providers, and specialists alike.

The most important things to know: take it exactly as prescribed, complete your full course, and make sure your doctor knows about all other medications you're taking — Clarithromycin has some significant drug interactions that need to be managed carefully.