Tetracycline antibiotic: Uses, side effects and quick guide

If your doctor mentioned a tetracycline antibiotic, here's what you need in plain language. Tetracyclines are a family of broad-spectrum antibiotics used for common infections like acne, respiratory infections, some STIs, and certain tick-borne illnesses. The most seen names are doxycycline, minocycline and the older tetracycline itself.

They work by stopping bacteria from making proteins they need to grow. That means they don’t kill every bug instantly but prevent it from multiplying so your immune system can finish the job. Because they cover a wide range of bacteria, doctors pick them when the exact germ isn’t known yet or for specific conditions where they work well.

When doctors prescribe them

You’ll commonly see tetracyclines prescribed for acne, rosacea, bronchitis, Lyme disease, chlamydia, and some skin and soft tissue infections. Doxycycline is the go-to for Lyme and many respiratory infections because it’s easy to take and tolerated well. Minocycline is often used for acne because it penetrates skin tissue effectively.

Not every infection should get a tetracycline. They don’t work for viral illnesses like colds or flu. Also, if the bug is known to be resistant, your clinician will choose a different antibiotic.

Side effects and safety tips

Common side effects are stomach upset, nausea, diarrhea, and increased sensitivity to sunlight. That last one means you can burn faster—use sunscreen and cover up. Avoid taking tetracyclines with dairy, calcium supplements, antacids, or iron pills within two hours of the dose; those bind the drug and make it less effective.

They’re not for everyone. Pregnant people and children under 8 should not take tetracyclines because these drugs can affect bone and tooth development. Tell your provider if you’re pregnant, breastfeeding, or have liver problems. Minocycline can sometimes cause dizziness or a skin discoloration with long use—mention this if you notice changes.

Finish the full course as prescribed, even if you feel better. Stopping early can let surviving bacteria become resistant, making future infections harder to treat. If side effects are severe—high fever, yellowing skin or eyes, severe belly pain—stop the medicine and seek medical care right away.

Resistance is a growing issue. Overuse and incorrect dosing make bacteria less sensitive to tetracyclines over time. That’s why prescribers try to be selective and may order tests to identify the right antibiotic.

Got questions about interactions with other meds or supplements? Ask your pharmacist or doctor—especially about oral contraceptives and blood thinners if you’re taking multiple drugs at once.

Store tetracyclines at room temperature away from heat and direct sunlight. Keep the bottle tightly closed and out of reach of children. 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. Always swallow pills with a full glass of water and stay upright for 30 minutes to avoid throat irritation.

Want more detailed reads on specific drugs like doxycycline or minocycline, dosing, and real-world tips? Browse our articles tagged with tetracycline antibiotic for patient-focused guides and safety checklists.