Before taking doxycycline,
tell your doctor and pharmacist if you are allergic to doxycycline, minocycline, tetracycline, demeclocycline, any other medications, sulfites, or any of the ingredients in doxycycline capsules, extended-release capsules, tablets, extended-release tablets, or suspension. Ask your pharmacist for a list of the ingredients.
tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: acitretin (Soriatane); anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven); barbiturates such as butabarbital (Butisol), phenobarbital, and secobarbital (Seconal); bismuth subsalicylate; carbamazepine (Epitol, Tegretol, others); isotretinoin (Absorica, Amnesteem, Clavaris, Myorisan, Zenatane); penicillin; phenytoin (Dilantin, Phenytek); and proton pump inhibitors such as dexlansoprazole (Dexilant), esomeprazole (Nexium, in Vimovo), lansoprazole (Prevacid, in Prevpac), omeprazole (Prilosec, in Yosprala, Zegerid), pantoprazole (Protonix), and rabeprazole (Aciphex). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
be aware that antacids containing magnesium, aluminum, or calcium, calcium supplements, iron products, and laxatives containing magnesium interfere with doxycycline, making it less effective. Take doxycycline 2 hours before or 6 hours after taking antacids, calcium supplements, and laxatives containing magnesium. Take doxycycline 2 hours before or 4 hours after iron preparations and vitamin products that contain iron.
tell your doctor if you have or have ever had lupus (condition in which the immune system attacks many tissues and organs including the skin, joints, blood, and kidneys), intracranial hypertension (pseudotumor cerebri; high pressure in the skull that may cause headaches, blurry or double vision, vision loss, and other symptoms), a yeast infection in your mouth or vagina, surgery on your stomach, asthma, or kidney or liver disease.
you should know that doxycycline may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, or injections). Talk to your doctor about using another form of birth control.
tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking doxycycline, call your doctor immediately. Doxycycline can harm the fetus.
plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Doxycycline may make your skin sensitive to sunlight. Tell your doctor right away if you get a sunburn.
you should know that when you are receiving doxycycline for prevention of malaria, you should also use protective measures such as effective insect repellent, mosquito nets, clothing covering the whole body, and staying in well-screened areas, especially from early nighttime until dawn. Taking doxycycline does not give you full protection against malaria.
you should know that when doxycycline is used during pregnancy or in babies or children up to 8 years of age, it can cause the teeth to become permanently stained. Doxycycline should not be used in children under 8 years of age except for inhalational anthrax, Rocky Mountain spotted fever, or if your doctor decides it is needed.