Tetracycline

1 medicine

Tetracycline is a broad-spectrum antibiotic that must be avoided in pregnancy and in children under 8, since it causes permanent tooth discolouration and can affect bone growth.

Sumycin

Tetracycline

250/500mg

Sumycin is a antibiotics medication containing Tetracycline, available as 250/500mg tablets.

from $0.25 / tablet View

Key facts

  • Tetracycline is a broad-spectrum antibiotic used for acne, some respiratory infections, and certain sexually transmitted infections.
  • Take it on an empty stomach with a full glass of water, sitting or standing upright. Keep it at least 1 to 2 hours away from dairy products, antacids, calcium, or iron supplements, which bind the drug and stop it working.
  • Never use it in pregnancy, while breastfeeding, or in children under 8. Tetracycline binds to growing bone and teeth, causing permanent yellow-grey tooth discolouration and can impair bone growth.
  • It also causes photosensitivity, a severe sunburn-like reaction after even brief sun exposure, so cover up and use sun protection throughout treatment.
  • Seek urgent care for severe headache with blurred or double vision.

What tetracycline treats

Tetracycline treats acne, respiratory infections including those caused by atypical organisms such as Mycoplasma pneumoniae, chlamydia infections, and infections from rickettsia such as Rocky Mountain spotted fever. It is also used as part of combination regimens to eradicate Helicobacter pylori.

How tetracycline works

Tetracycline enters bacterial cells and attaches to the bacterial ribosome, the machinery bacteria use to build proteins. By blocking protein production, it stops bacteria from growing and multiplying, allowing the immune system to clear the remaining infection.

Before you take it

  • Do not take it if you are pregnant, breastfeeding, or under 8 years old, because of permanent effects on developing teeth and bone.
  • Tell your prescriber about kidney disease, since the dose may need adjusting, and about any past episode of raised pressure inside the skull (idiopathic intracranial hypertension), which tetracyclines can trigger or worsen.
  • Do not take dairy products, antacids, or calcium, iron or magnesium supplements within 2 hours of a dose, as they block absorption.
  • Never take tetracycline past its expiry date; degraded tetracycline has caused kidney damage.

Side effects

Common effects include nausea, diarrhoea, and increased sensitivity to sunlight.

Stop and seek urgent medical care for any of these:

  • Severe headache with blurred or double vision, which may signal raised pressure inside the skull.
  • Severe or bloody diarrhoea.
  • Signs of an allergic reaction: rash, facial swelling, or difficulty breathing.
  • Severe sunburn after minimal sun exposure.

Safety essentials

  • The pregnancy and under-8 rule is absolute: tetracycline permanently discolours developing teeth and can impair bone growth in the fetus and in young children, so it is avoided completely in these groups.
  • Swallow each dose with plenty of water while upright, and stay upright afterward, to stop the tablet lodging and irritating the oesophagus.
  • Use sunscreen and protective clothing and avoid prolonged sun or UV exposure for the whole course of treatment.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.