Active substances: Doxycycline
It's used to treat infections such as chest infections, skin infections, rosacea, dental infections and sexually transmitted infections STIs, as well as a lot of other rare infections.
It can also be used to prevent malaria if you're travelling abroad. Doxycycline is available on prescription. It comes as capsules.
Key facts For most infections, you'll start to feel better in a few days but it is important to finish the course of medicine. The most common side effects of doxycycline are headaches, feeling or being sick.
It can also make your skin sensitive to the sun. Doxycycline can affect growing teeth so it's not prescribed for children under 12 years old or given to pregnant and breastfeeding women. Do not drink alcohol while taking doxycycline.
There are also some common medicines you should not mix with it.
Doxycycline can also be called by the brand name Vibramycin-D. Who can and can't take doxycycline Doxycycline can be taken by adults and children over 12 years old.
Doxycycline is not usually recommended in pregnancy or when breastfeeding. It isn't suitable for some people.
It works by preventing bacteria from reproducing through the inhibition of protein synthesis.
It can also be re-absorbed in the renal tubules and gastrointestinal tract due to its high lipophillicity so has a long elimination half life, and does not accumulate in the kidneys of patients with kidney failure due to the compensatory excretion in faeces.
It inhibits the synthesis of bacterial proteins by binding to the 30 S ribosomal subunit, which is only found in bacteria. This stops bacterial growth giving the immune system time to kill and remove the bacteria.
American Cyanamid was one of these, and in the late 1940 s chemists there discovered chlortetracycline, the first member of the tetracycline class of antibiotics.
Keep taking the medicine, but talk to your doctor or pharmacist if these side effects bother you or don't go away: headaches feeling or being sick nausea or vomiting being sensitive to sunlight Serious side effects are rare and happen in less than 1 in 1,000 people.
In rare cases, doxycycline can cause a serious allergic reaction anaphylaxis. These are not all the side effects of doxycycline. For a full list see the leaflet inside your medicines packet.
Information: You can report any suspected side effect to the UK safety scheme.
How to cope with side effects What to do about: headaches - make sure you rest and drink plenty of fluids. Everyday painkillers, such as paracetamol and ibuprofen, are safe to take with doxycycline.
It might help to take your doxycycline after a meal or snack but avoid dairy products like milk, cheese and yoghurt.
Dairy products can stop your body absorbing your medicine properly.
If you are being sick, drink plenty of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having strong-smelling pee.