Clarithromycin: Uses, Side Effects, and What You Need to Know
When you’re prescribed clarithromycin, a macrolide antibiotic used to treat bacterial infections like pneumonia, sinusitis, and H. pylori stomach infections. Also known as Biaxin, it works by stopping bacteria from growing, not by killing them outright. It’s one of the most commonly prescribed antibiotics for respiratory and digestive tract infections, but it’s not harmless — and not always the right choice.
Clarithromycin belongs to the macrolide antibiotics, a class of drugs that includes azithromycin and erythromycin, often used when patients can’t take penicillin. Unlike some antibiotics that attack a wide range of bacteria, clarithromycin targets specific strains, which makes it useful for stubborn infections like H. pylori — the bacteria that cause most ulcers. But overuse has led to rising antibiotic resistance, a growing problem where bacteria evolve to survive even strong drugs like clarithromycin. In some regions, up to 20% of H. pylori strains no longer respond to it, forcing doctors to switch to other combinations.
Side effects are common but usually mild: nausea, diarrhea, and a strange metallic taste in your mouth. Less than 5% of people have serious reactions like liver problems or heart rhythm changes, especially if they’re on other meds like statins or blood thinners. If you’ve ever been told you’re allergic to erythromycin, you should avoid clarithromycin — they’re too similar. And if you’re taking it for H. pylori, you’ll likely get it with two other drugs, because using it alone makes resistance more likely.
What you won’t find in most doctor’s offices is how often clarithromycin is misused. People take leftover pills for sore throats or colds — even though it does nothing against viruses. That’s not just ineffective; it’s dangerous. Every unnecessary dose adds to the pile of resistant bacteria we’re all stuck with. The real question isn’t just whether clarithromycin works — it’s whether you really need it.
Below, you’ll find real stories and practical advice from people who’ve used clarithromycin — and others who’ve had to find alternatives. Some learned the hard way about side effects. Others discovered how to spot fake pills online. A few found out their "allergy" wasn’t real. This isn’t just a list of articles. It’s a guide to using this drug safely, wisely, and only when it truly matters.
