Biaxin (clarithromycin): what it treats and how to use it safely

Biaxin (generic: clarithromycin) is a macrolide antibiotic doctors commonly prescribe for chest infections, sinusitis, skin infections, and some stomach bugs caused by H. pylori. It stops bacteria from growing so your immune system can finish the job. That sounds simple, but using it the right way matters for safety and to avoid resistance.

How to take Biaxin safely

Follow your prescription exactly. Common adult doses are 250–500 mg twice daily, but your doctor may adjust that based on the infection and your health. Take it with or without food depending on the label—some forms are easier on the stomach with food. Keep a steady schedule so blood levels stay consistent. 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 to catch up.

Finish the full course even if you feel better after a few days. Stopping early can let bacteria survive and become resistant. If symptoms don’t improve in 48–72 hours, call your doctor—sometimes a different antibiotic or further testing is needed.

Common side effects and when to worry

Most people handle Biaxin fine. The common side effects are nausea, taste changes, diarrhea, and mild stomach pain. These often pass after a day or two. Serious reactions are less common but important: severe allergic reactions (rash, swelling, breathing trouble), signs of liver trouble (jaundice, dark urine, severe belly pain), and a rare but dangerous heart rhythm issue (especially if you already have heart disease).

If you notice severe symptoms, stop taking the drug and get medical help right away. Also call your provider if diarrhea is severe or contains blood—this can signal C. difficile infection, which needs prompt treatment.

Biaxin can interact with several medicines. Combining it with certain statins (like simvastatin), some blood thinners (warfarin), colchicine, or certain heart rhythm drugs raises risk for serious side effects. Tell your doctor about ALL medications, including over-the-counter drugs and supplements. If you take multiple meds, your provider may pick a safer antibiotic.

Pregnancy and breastfeeding: talk to your doctor. Clarithromycin is usually avoided in pregnancy unless the benefits clearly outweigh risks. It can pass into breast milk, so discuss alternatives if you’re nursing.

Storage and buying: store tablets at room temperature away from moisture. Biaxin is prescription-only in most places—don’t buy antibiotics from sketchy online sellers. Use licensed pharmacies and keep records of what you take.

Want to avoid preventable problems? Use antibiotics only when needed, follow dosing, watch for interactions, and call your doctor for persistent or worsening symptoms. That keeps you safer and helps keep antibiotics working for everyone.