Make sure your diet provides vitamin B. Ask your prescriber or health care professional for advice if you think you are short of this vitamin. Use an extra method of birth control for at least one month. If you are being treated for a sexually transmitted disease, avoid sexual contact until you have finished your treatment. Your sexual partner may also need treatment. If you are going to have surgery, tell your prescriber or health care professional that you are taking doxycycline.
Antacid can stop doxycycline working.
If you get an upset stomach and want to take an antacid, make sure there is an interval of at least 2 hours since you last took doxycycline, or 4 hours before your next dose. Keep out of the reach of children in a container that small children cannot open.