Tetracycline Dosage: What You Need to Know

Getting the right amount of tetracycline can be the difference between beating an infection and dealing with side effects. This guide breaks down the typical doses, how to adjust them for kids, and simple tricks to make the drug work better for you.

Typical Adult Dosing

For most infections, doctors prescribe 250 mg to 500 mg every 6 to 12 hours. A common schedule is 500 mg twice a day for 7‑10 days. If your infection is mild, you might see a lower dose like 250 mg three times daily. Always follow the exact timing your prescriber gives – it helps keep the drug level steady in your blood.

Kids and Weight‑Based Dosing

Children don’t get the same flat dose as adults. The usual rule is 25 mg per kilogram of body weight per day, split into two or three doses. For example, a 20 kg child would take about 500 mg total in a day, divided into 250 mg every 12 hours. Your doctor will calculate the exact amount based on the child’s age, weight and the infection being treated.

How Food and Supplements Affect Absorption

Tetracycline doesn’t like calcium, iron or aluminum. Taking it with dairy, antacids or multivitamins can drop the amount your body absorbs by up to 50 %. The safest move is to take the pill on an empty stomach – at least one hour before or two hours after meals. If stomach upset is a problem, a small snack that’s low in calcium (like a plain cracker) is usually fine.

Safety Tips and When to Call a Doctor

Watch for severe stomach pain, persistent diarrhea, or a rash that spreads quickly. Those could signal a serious reaction. If you notice bright yellow skin or eyes, that might be a sign of liver trouble and needs immediate medical attention. Also, avoid sun exposure – tetracycline can make you sun‑sensitive, so wear sunscreen or protective clothing.

Common Duration and What to Expect

Most courses last 7‑14 days, but some infections (like acne) may require weeks or months of treatment. Even if you feel better after a few days, finish the full prescription. Stopping early can let the bacteria survive and become resistant, which makes future infections harder to treat.

Quick Dosage Cheat Sheet

• Adults: 250‑500 mg every 6‑12 h
• Children: 25 mg/kg/day in 2‑3 divided doses
• Take on an empty stomach – avoid dairy, antacids, iron
• Finish the entire course, even if you feel fine
• Watch for rash, severe stomach pain, yellow skin, or sun‑sensitivity