Tetracycline Dosage: What You Need to Know

If you’ve been prescribed tetracycline, the biggest question is probably "how much should I take?" The answer depends on what you’re treating, your age, weight, and how healthy your kidneys are. Below is a straightforward rundown that you can keep handy when you pick up the prescription.

Standard Doses for Common Infections

For most adult infections – like acne, bronchitis, or urinary tract infections – doctors start you on 250 mg to 500 mg every 6 to 12 hours. A typical course lasts 7 to 14 days, but skin infections sometimes need a longer stretch, up to 4 weeks. If you’re dealing with a serious thing like Rocky Mountain spotted fever, the dose jumps to 500 mg every 6 hours.

Kids get a lower dose. Pediatric guidelines recommend 25 mg per kilogram of body weight per day, divided into two or four doses. For a 30‑kg child that works out to about 750 mg a day, split into 250 mg three times daily.

Special Situations: Kidney Problems, Pregnancy, and More

Kidney function matters because tetracycline is cleared through the kidneys. If your doctor notes reduced kidney function, they’ll usually cut the dose by half or extend the interval between doses. Never guess – ask your pharmacist for the exact adjustment.

Pregnant people should avoid tetracycline altogether. The drug can stick to developing teeth and bones, causing discoloration and growth issues. The same rule applies to nursing moms – it passes into breast milk and could affect the baby’s teeth.

Elderly patients often need a lower dose, too. Age‑related kidney decline and the higher chance of drug interactions make a conservative approach safer.

Take the pill with a full glass of water and stay upright for at least 30 minutes. This prevents irritation of the esophagus, a common complaint with tetracycline.

Don’t take it with dairy, antacids, or iron supplements within two hours of each other. Those minerals bind to the drug and stop your body from absorbing it, making the whole treatment less effective.

If you miss a dose, take it as soon as you remember – but if it’s almost time for the next dose, just skip the missed one. Doubling up can cause nausea and stomach upset.

Side effects are usually mild: nausea, vomiting, and a sun‑sensitive skin reaction are the most common. If you notice a rash, severe diarrhea, or any sign of an allergic reaction, call your doctor right away.

When the course ends, you might see a temporary change in stool color or a slight metallic taste. Those are harmless and should fade quickly.

Remember, finishing the full prescription is key. Stopping early can let bacteria survive and become resistant, which makes future infections harder to treat.

Bottom line: follow the exact dose your doctor gives, adjust for age or kidney health if needed, and avoid dairy and antacids around the time you take the pill. With those basics in place, tetracycline works well for a wide range of infections without causing trouble.