Tetracycline uses: what they treat and what to watch for
Tetracyclines are a group of antibiotics you’ll see often in clinics. Doxycycline and minocycline are the most common today. Doctors prescribe them for a wide range of infections because they work against many kinds of bacteria. If you want a quick, practical view of when they’re used and how to take them right, this page gives the basics.
Common uses include acne treatment, respiratory infections like bronchitis and sinusitis, certain urinary tract infections, and sexually transmitted infections such as chlamydia. They’re also a go-to for specific bugs like rickettsial infections (e.g., Rocky Mountain spotted fever), early Lyme disease, and some forms of stomach or skin infections. Doxycycline can be used for malaria prevention in travelers and for certain eye infections as well.
How to take tetracyclines safely
Take tetracyclines exactly as your doctor says. Swallow pills with a full glass of water and avoid lying down right after to reduce the risk of throat or esophagus irritation. Don’t take them with milk, calcium-fortified juices, antacids, or iron supplements — those products bind the drug and make it less effective. If you need to take a calcium or iron product, separate it by at least two hours.
For acne, treatment often lasts weeks to months; for many infections, a short course of 7–14 days is common. Stick to the full course even if you feel better early — stopping too soon can let the infection return and encourage resistance.
Side effects and safety — who should be careful
Most people tolerate tetracyclines, but expect possible nausea, diarrhea, and sun sensitivity. The sun sensitivity can be strong: you may burn more easily, so use sunscreen and cover up outdoors. A rare but serious issue is esophageal irritation or ulcers if pills aren’t swallowed properly.
Avoid tetracyclines during pregnancy and in children younger than eight years old. They can permanently stain developing teeth and affect bone growth. If you’re pregnant, breastfeeding, or treating a child, talk to your clinician about safer alternatives.
Also mention any other medicines you take. Tetracyclines can interact with blood thinners, some heart medications, and supplements that contain metal ions. If you’re on long-term meds, check with your prescriber or pharmacist.
Resistance is a real concern. If your symptoms don’t improve within a few days of starting therapy—or if they get worse—contact your healthcare provider. Sudden severe belly pain, high fever, or signs of an allergic reaction (rash, swelling, trouble breathing) need urgent care.
If you want personalized advice, bring a list of your meds and allergies to your appointment. Tetracyclines are useful when used correctly; with the right precautions they can treat many infections effectively and safely.