Doxycycline
A tetracycline for chest infections, penicillin allergy, chlamydia, brucellosis and cholera. 200 mg on day 1 then 100 mg daily for most infections.
On this page
Uses
- Chest infection or pneumonia (penicillin allergy).
- Cellulitis in penicillin allergy.
- Chlamydia, epididymo-orchitis (with ceftriaxone).
- Brucellosis (with rifampicin or streptomycin), leptospirosis, scrub typhus, cholera.
Adult dose
| Indication | Dose |
|---|---|
| Chest infection, cellulitis | 200 mg on day 1, then 100 mg once daily for 5–7 days |
| Chlamydia, epididymo-orchitis | 100 mg twice daily for 7 days (10–14 days for epididymo-orchitis) |
| Brucellosis | 100 mg twice daily for 6 weeks with rifampicin (specialist) |
| Cholera | 300 mg single dose |
Children
Avoid under 12 years (tooth staining) except where benefits outweigh risks (for example, short courses for serious infections per specialist).
Kidney and liver
No adjustment in kidney impairment.
Pregnancy and breastfeeding
Avoid in pregnancy and breastfeeding.
Side effects and cautions
- Take with plenty of water, sitting up (oesophageal ulcers).
- Sun sensitivity.
- Don't take with antacids, iron, calcium or milk at the same time.
Frequently asked questions
What is the doxycycline dose for a chest infection?
200 mg on the first day, then 100 mg daily for 5 days.
Can doxycycline be given in pregnancy?
No. It should be avoided in pregnancy and in children under 12.
Used in these guides
Sources
Doses on this page are typical doses from the sources above. Always confirm with a current drug reference, the product leaflet and your hospital protocol, especially in children, pregnancy and kidney or liver disease.
For FCPS Part 1
Revising for FCPS Part 1? Doxycycline is covered in our textbook chapter Antimicrobials in pregnancy, with practice MCQs.