Do not take antacids or bismuth subsalicylate within 1 to 2 hours of taking doxycycline. In addition, do not take iron-containing medication - including vitamin preparations containing iron within 2 to 3 hours of taking doxycycline. To do so may keep doxycycline from help you.
Oral contraceptives - birth control pills may not work properly if you take them while you are taking tetracyclines. Unplanned pregnancies may occur. You must use a various or additional means of birth control while you are taking doxycycline. If you have any questions about this, check with your family doctor.
Before having surgery - including dental surgery with a general anesthetic, tell the family doctor or dentist in charge that you are taking doxycycline.
Some people who take tetracyclines may become more sensitive to sunlight than they are normally. Exposure to sunlight, even for brief periods of time, may cause severe sunburn; skin rash, redness, itching, or discoloration; or vision changes. When you begin taking this drug: