Clarithromycin Explained: What It Is and When You Might Need It

Clarithromycin is a type of antibiotic that fights bacteria in your body. Doctors often prescribe it for lung infections, skin problems, ear infections, and things like strep throat. It belongs to the macrolide family, which means it works by stopping bacteria from growing, not by killing them outright. If you’ve ever been told to take a “macrolide,” that’s probably clarithromycin.

One reason doctors like it is that it can be taken once or twice a day, which is easier than some antibiotics that need to be taken four times daily. It also comes in tablets, a liquid form for kids, and even a chewable version in some countries. Knowing the right form for you makes the whole treatment smoother.

How to Take Clarithromycin – Dosage Made Simple

Typical adult dosing is 250 mg to 500 mg every 12 hours for 7‑10 days, but the exact amount depends on the infection you have. For a middle‑ear infection, a doctor might prescribe 250 mg twice a day for 10 days. If you have a more serious lung infection like pneumonia, the dose could go up to 500 mg twice daily.

Kids get a dose based on weight, usually around 7.5 mg per kilogram of body weight every 12 hours. The liquid form makes it easy to measure, but always use the syringe or cup that comes with the medication to avoid mistakes.

Take the medicine with or without food—just try to be consistent each day. If you miss a dose, take it as soon as you remember, unless it’s almost time for the next one. Don’t double up; that can increase side‑effects.

Common Side Effects and When to Call the Doctor

Most people feel fine, but some experience stomach upset, nausea, or a mild rash. These usually go away on their own. If you get a high fever, severe diarrhea, or notice your stool turning bright yellow, that could be a sign of a more serious reaction called Clostridioides difficile infection—call your doctor right away.

Rarely, clarithromycin can affect your heart rhythm, especially if you have a history of heart problems. Symptoms like fast or irregular heartbeat, dizziness, or fainting should be reported immediately.

Allergies are also possible. If you develop hives, swelling of the face or throat, or trouble breathing, treat it like an emergency and seek help.

Because clarithromycin can interact with many other drugs—like certain cholesterol medicines, blood thinners, and some anti‑seizure meds—always tell your doctor about every prescription, over‑the‑counter product, and supplement you’re taking.

In short, clarithromycin works well for many bacterial infections when you follow the dosage instructions and watch for side effects. Talk to your healthcare provider if anything feels off, and you’ll keep the treatment on track.