Sounds like 'dox-i-sye- kleen'

Easy-to-read medicine information about doxycycline – what it is, how to take doxycycline safely and possible side effects.

 Type of medicine

 Also called

  • Antibiotic (to treat infections)
  • Tetracycline antibiotic
  • Doxine
  • Doxy

What is doxycycline?

  • Doxycycline is part of the tetracycline group of antibiotics.
  • It is used to treat infections of the chest, sinus, eye and pelvic infections.
  • Doxycycline is also used to treat skin conditions such as acne, rosacea and perioral dermatitis.
  • For travel to some countries, doxycycline is also used for malaria prevention.


  • The usual dose of doxycycline is 100 mg either once or twice daily, depending of the type of infection.
  • The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions. 

How to take doxycycline

  • Take doxycycline with food and a large glass of water.
  • Remain upright for at least 30 minutes after taking doxycycline. Do not lie down for at least 30 minutes after taking doxycycline or do not take it just before bed.
  • Take doxycycline at least 1 hour before or 2 hours after antacids (including sodium bicarbonate), calcium supplements, and laxatives containing magnesium.
  • Take doxycycline at least 2 hours before or 3 hours after iron preparations and vitamin products that contain iron.
  • Limit or avoid alcohol while you are taking doxycycline.
  • Do not stop taking doxycycline, even if you feel better after a few days.
  • If you forget to take doxycycline, take it as soon as you remember.
  • But, if it is nearly time for your next dose, just take it at the right time; do not take double the amount.

Special instructions

  • Doxycycline may make your skin more sensitive to the sun. You may get a burning, tingling feeling on your skin when you are in the sun, or you may notice a darker tan, or redness.
  • When outside, protect your skin and eyes by using a good sunscreen (SPF30+). a sunhat and clothing that protects you from the sun, and wearing sunglasses.

Possible side effects

Like all medicines, doxycycline can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Nausea (feeling sick) or vomiting
  • Take doxycycline after a meal.
  • Diarrhoea (loose, watery stools)
  • These may go away with time.
  • Tell your doctor if troublesome.
  • Vaginal itching, soreness or discharge (thrush)
  • Tell your doctor or pharmacist.
  • Allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing
  • Tell your doctor immediately or ring HealthLine.


  • Doxcycyline interacts with a number of medications including antacids, anticoagulants ('blood thinners') such as warfarin (Coumadin), carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), and some vitamins.
  • If you are taking the contraceptive pill (birth control pill), it may become less effective while you are taking doxycycline. Consider using a barrier form of birth control such as condoms, or diaphragms.

Learn more

Medsafe Consumer Information Sheet: Doxine

New Zealand Formulary Patient Information: Doxycycline

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft. Health Navigator NZ Last reviewed: 11 Feb 2015