Doxycycline

What is Doxycycline?

Doxycycline is a broad-spectrum tetracycline antibiotic used against a wide variety of bacterial infections, including Rocky Mountain spotted fever and other fevers caused by ticks, fleas, and lice; urinary tract infections; trachoma (chronic infections of the eye); and some gonococcal infections in adults. It is an approved treatment for inhalational anthrax. It is also used with other medications to treat severe acne and amoebic dysentery (diarrhea caused by severe parasitic infection of the intestines).

Doxycycline may also be taken for the prevention of malaria on foreign trips of less than 4 months' duration.

What is the most important information I should know about Doxycycline?

Generally, children under 8 years old and women in the last half of pregnancy should not take this medication. It may cause developing teeth to become permanently discolored. (However, children under 8 may be given this drug for inhalational anthrax.)

As with other antibiotics, treatment with doxycycline may result in a growth of bacteria that do not respond to this medication and can cause a secondary infection. An overgrowth of certain bacteria in the colon could cause mild to severe—and rarely, life-threatening—diarrhea. If you develop this symptom, call your doctor immediately.

Who should not take Doxycycline?

If you are sensitive to or have ever had an allergic reaction to doxycycline or drugs of this type, you should not take this medication. Make sure your doctor is aware of any drug reactions that you have experienced.

What should I tell my doctor before I take the first dose of Doxycycline?

Tell your doctor about all prescription, over-the-counter, and herbal medication you are taking before beginning treatment with this drug. Also, talk to your doctor about your complete medical history, especially if you are allergic to sulfites (the syrup formulation contains this preservative).

Also tell the doctor if you use birth control pills that contain estrogen, since they may not be as effective while you are taking tetracycline drugs. Ask your doctor or pharmacist if you should use another form of birth control while taking doxycycline.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Adults: The usual dose of oral doxycycline is 200 milligrams (mg) on the first day of treatment (100 mg every 12 hours) followed by a maintenance dose of 100 mg per day. The maintenance dose may be taken as a single dose or as 50 mg every 12 hours.

Your doctor may prescribe 100 mg every 12 hours for severe infections such as chronic urinary tract infection.

For Uncomplicated Gonorrhea (Except Anorectal Infections in Men)

The usual dose is 100 mg by mouth, twice a day for 7 days. An alternate, single-day treatment is 300 mg, followed in 1 hour by a second 300-milligram dose.

For Primary and Secondary Syphilis

The usual dose is 200 mg a day, divided into smaller, equal doses for 14 days.

For Inhalational Anthrax

To prevent or combat infection after exposure, the usual dose is 100 mg taken by mouth twice a day for 60 days. Treatment can be started intravenously, but should be switched to oral doses as soon as possible.

For Prevention of Malaria

The usual dose is 100 mg a day. Treatment should begin 1 to 2 days before travel to the area where malaria is found, then continue daily during travel in the area and 4 weeks after leaving.

Children: For children above 8 years of age, the recommended dosage schedule for those weighing 100 pounds or less is 2 mg per pound of body weight, divided into 2 doses, on the first day of treatment, followed by 1 milligram per pound of body weight given as a single daily dose or divided into 2 doses on subsequent days.

For more severe infections, up to 2 mg per pound of body weight may be used.

For inhalational anthrax in children weighing less than 100 pounds, the usual dose is 1 milligram per pound of body weight twice daily for 60 days.

For prevention of malaria, the recommended dose is 2 mg per 2.2 pounds of body weight up to 100 mg.

For children over 100 pounds, the usual adult dose should be used.

How should I take Doxycycline?

Take doxycycline with a full glass of water or other liquid to avoid irritating your throat or stomach. Doxycycline can be taken with or without food. However, if the medicine does upset your stomach, you may wish to take it with a glass of milk or after you have eaten.

Doxycycline tablets should be swallowed whole. If you have difficulty swallowing pills, you can take this medication by opening the capsule and sprinkling the entire contents onto a spoonful of cool, soft applesauce. Be careful not to spill any of the contents. If you do, you will not be able to use this dose and will have to start over with a new mixture. Swallow the mixture immediately, without chewing, followed by a cool 8-ounce glass of water. Discard the mixture if you are not able to use it immediately; do not store it to use later.

Your doctor will only prescribe doxycycline to treat a bacterial infection; it will not cure a viral infection, such as the common cold. It's important to take the full dosage schedule of doxycycline, even if you're feeling better in a few days. Not completing the full dosage schedule may decrease the drug's effectiveness and increase the chances that the bacteria may become resistant to doxycycline and similar antibiotics.

If you are taking an oral suspension form of doxycycline, shake the bottle well before using. Do not use outdated doxycycline.

What should I avoid while taking Doxycycline?

You may become more sensitive to light while taking doxycycline. Be careful if you are going out in the sun or using a sunlamp. If you develop a skin rash, notify your doctor immediately.

What are possible food and drug interactions associated with Doxycycline?

If doxycycline is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining doxycycline with the following:

Antacids containing aluminum, calcium, or magnesium, and iron-containing preparations,Barbiturates such as phenobarbital,Bismuth subsalicylate,Blood-thinning medications such as warfarin,Carbamazepine,Oral contraceptives,Penicillin,Phenytoin,Sodium bicarbonate

What are the possible side effects of Doxycycline?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking doxycycline.

Side effects may include: Angioedema (chest pain; swelling of face, around lips, tongue and throat, arms and legs; difficulty swallowing), diarrhea, difficulty swallowing, discolored teeth in infants and children (more common during long-term use of tetracycline), inflammation of the tongue, loss of appetite, nausea, rash, rectal or genital itching, severe allergic reaction (hives, itching, and swelling), skin sensitivity to light, vomiting

Can I receive Doxycycline if I am pregnant or breastfeeding?

Doxycycline should not be used during pregnancy. Tetracycline can damage developing teeth during the last half of pregnancy. If you are pregnant or plan to become pregnant, inform your doctor immediately. Tetracyclines such as doxycycline appear in breast milk and can affect a nursing infant. Consult your doctor before breastfeeding.

What should I do if I miss a dose of Doxycycline?

If you miss a dose of this drug, skip it. Do not take an extra dose to make up for missed doses. If you miss two or more doses in a row, check with your doctor or pharmacist.

How should I store Doxycycline?

Store at room temperature. Protect from light and excessive heat.