Clarithromycin Is a Prescription Macrolide Antibiotic Used to Treat Bacterial Infections of the Lungs, Sinuses, Skin, and Stomach

If your doctor just prescribed Clarithromycin — or you're trying to understand what it is before your appointment — this guide covers everything you need to know in plain language: what it's for, how to take it, what it costs, and what to watch out for.

What Is Clarithromycin?

Clarithromycin is a macrolide antibiotic — the same family of antibiotics that includes Azithromycin (Z-Pack) and Erythromycin. It was originally sold under the brand name Biaxin, manufactured by AbbVie. The brand-name version has been discontinued in the US, but Clarithromycin is widely available as a generic from manufacturers like Teva, Sandoz, Sun Pharma, and Aurobindo.

Clarithromycin is not a controlled substance. It's a standard prescription antibiotic — no DEA scheduling, no special prescribing requirements.

It works by blocking bacteria from making the proteins they need to survive and multiply. At typical doses, it stops bacterial growth (bacteriostatic), and at higher concentrations, it can kill bacteria directly (bactericidal).

What Is Clarithromycin Used For?

Clarithromycin has FDA approval for treating several types of bacterial infections:

• Community-acquired pneumonia — A common lung infection often picked up in daily life (not in a hospital)
• Acute bacterial exacerbation of chronic bronchitis — A flare-up of bronchitis caused by bacteria
• Acute maxillary sinusitis — Bacterial sinus infection
• Pharyngitis/tonsillitis — Strep throat and tonsil infections (used as an alternative to Penicillin)
• Uncomplicated skin and skin structure infections — Bacterial skin infections like cellulitis or impetigo
• Disseminated Mycobacterium avium complex (MAC) infections — Both treatment and prevention, commonly in immunocompromised patients
• Helicobacter pylori eradication — Used in combination with other drugs (like Amoxicillin and a proton pump inhibitor) to treat stomach ulcers caused by H. pylori
• Acute otitis media — Middle ear infections in children

Doctors also sometimes prescribe Clarithromycin off-label for conditions like Lyme disease, pertussis (whooping cough), Bartonella infections, dental infections, and Legionella pneumonia.

How Is Clarithromycin Taken?

Clarithromycin comes in three main forms:

• Immediate-release tablets — 250 mg and 500 mg. Taken twice daily.
• Extended-release tablets (Clarithromycin ER/XL) — 500 mg. Taken once daily (two tablets = 1,000 mg dose).
• Oral suspension — 125 mg/5 mL and 250 mg/5 mL. A liquid form primarily used for children.

Dosing Basics

The typical adult dose is 250 mg to 500 mg twice daily for immediate-release tablets, or 1,000 mg once daily for extended-release. Your doctor will choose the dose based on your infection type and severity.

A typical course lasts 7 to 14 days. For H. pylori treatment, you'll usually take Clarithromycin as part of a triple or quadruple therapy regimen for 10 to 14 days.

Important Instructions

• Immediate-release tablets and oral suspension can be taken with or without food.
• Extended-release tablets MUST be taken with food — this is required for proper absorption.
• Do not crush, chew, or break extended-release tablets.
• Shake the oral suspension well before each dose. Store it at room temperature (do not refrigerate). Discard any unused suspension after 14 days.
• Complete the full course — even if you feel better after a few days. Stopping early can lead to antibiotic resistance and a return of the infection.

Who Should NOT Take Clarithromycin?

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

• Have a known allergy to Clarithromycin, Erythromycin, or any macrolide antibiotic
• Have a history of liver problems (cholestatic jaundice or liver dysfunction) from previous Clarithromycin use
• Are taking any of these medications: Cisapride, Pimozide, Ergotamine, Dihydroergotamine, Lomitapide, Lovastatin, or Simvastatin
• Have liver or kidney impairment and are taking Colchicine
• Have a history of QT prolongation or irregular heart rhythms

Make sure your doctor has a complete list of your medications before starting Clarithromycin. It has significant drug interactions that can cause serious problems.

Special Populations

• Pregnancy: Category C — not proven safe in humans. Use only if benefit outweighs risk.
• Breastfeeding: Clarithromycin passes into breast milk. Discuss with your doctor.
• Children: Approved for ages 6 months and older. Oral suspension is available for pediatric dosing.
• Kidney impairment: Dose adjustment required if creatinine clearance is below 30 mL/min.
• Elderly patients: May be more susceptible to heart rhythm side effects.

How Much Does Clarithromycin Cost?

Here's what you can expect to pay in 2026:

• With a discount coupon (GoodRx, SingleCare, etc.): Approximately $16 to $50 for a typical 14-day course of 500 mg tablets.
• Retail cash price (no coupon, no insurance): Approximately $110 to $148.
• With insurance: Most plans cover generic Clarithromycin as a Tier 1 or Tier 2 drug. Your copay will depend on your plan, but it's generally affordable — often $5 to $25.

Since the brand-name Biaxin has been discontinued in the US, there's no manufacturer savings card. But generic pricing is competitive, and discount coupons can cut costs significantly.

For a full breakdown of savings options, see our guide on how to save money on Clarithromycin.

Final Thoughts

Clarithromycin is a well-established, widely available antibiotic that's been used for decades. It's effective for a broad range of bacterial infections, reasonably priced as a generic, and covered by most insurance plans.

The most important things to remember: take it as directed, finish your full course, tell your doctor about all your medications (interactions are a real concern with this drug), and know the side effects to watch for.

If you need help finding a pharmacy with Clarithromycin in stock, Medfinder can help you locate it near you.