Some commonly used TETRACYCLINE Brand Names are:

In the U.S.—

In Canada—

• Antiacne agent, systemic --Minocycline; tetracycline
• Antibacterial, systemic --Demeclocycline; doxycycline; minocycline ; oxytetracycline; tetracycline
• Antiprotozoal --Demeclocycline; doxycycline ; minocycline; oxytetracycline; tetracycline
• Antirheumatic --Minocycline
• Diuretic, syndrome of inappropriate antidiuretic hormone --Demeclocycline
• Intrapleural sclerosing agent --Doxycycline; tetracycline

Tetracyclines are used to treat infections and to help control acne. Demeclocycline, doxycycline, and minocycline also may be used for other problems as determined by your doctor. Tetracyclines will not work for colds, flu, or other virus infections.

Tetracyclines are available only with your doctor's prescription, in the following dosage forms:

Oral
• Demeclocycline
  • Tablets (U.S. and Canada)
• Doxycycline
  • Capsules (U.S. and Canada)
  • Delayed-release capsules (U.S. )
  • Oral suspension (U.S.)
  • Tablets (U.S. and Canada)
• Minocycline
  • Capsules (U.S. and Canada)
  • Oral suspension (U.S.)
• Oxytetracycline
  • Capsules (U.S.)
• Tetracycline
  • Capsules (U.S. and Canada)
  • Oral suspension (Canada)

Parenteral
• Doxycycline
  • Injection (U.S.)
• Minocycline
  • Injection (U.S.)
• Oxytetracycline
  • Injection (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For tetracyclines, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to any of the tetracyclines or combination medicines containing a tetracycline. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes. In addition, if you are going to be given oxytetracycline by injection, tell your doctor if you have ever had an unusual or allergic reaction to ``caine-type'' anesthetics (e.g., lidocaine).

Pregnancy—Use is not recommended during the last half of pregnancy. If tetracyclines are taken during that time, they may cause the unborn infant's teeth to become discolored and may slow down the growth of the infant's teeth and bones. In addition, liver problems may occur in pregnant women, especially those receiving high doses by injection into a vein.

Breast-feeding—Use is not recommended since tetracyclines pass into breast milk. They may cause the nursing baby's teeth to become discolored and may slow down the growth of the baby's teeth and bones. They may also increase the sensitivity of nursing babies' skin to sunlight and cause fungus infections of the mouth and vagina. In addition, minocycline may cause dizziness, light-headedness, or unsteadiness in nursing babies.

Children—Tetracyclines may cause permanent discoloration of teeth and slow down the growth of bones. These medicines should not be given to children 8 years of age and younger unless directed by the child's doctor.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of tetracyclines in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tetracyclines, it is especially important that your health care professional know if you are taking any of the following:

• Antacids or
• Calcium supplements such as calcium carbonate or
• Cholestyramine (e.g., Questran) or
• Choline and magnesium salicylates (e.g., Trilisate) or
• Colestipol (e.g., Colestid) or
• Iron-containing medicine or
• Laxatives (magnesium-containing) or
• Magnesium salicylate (e.g., Magan)—Use of these medicines with tetracyclines may decrease the effect of tetracyclines

• Oral contraceptives (birth control pills) containing estrogen—Use of birth control pills with tetracyclines may decrease the effect of the birth control pills and increase the chance of unwanted pregnancy
• Penicillins—Use of tetracyclines with penicillins may decrease the effect of penicillins

• Diabetes insipidus (water diabetes)—Demeclocycline may make the condition worse

• Kidney disease (does not apply to doxycycline or minocycline)—Patients with kidney disease may have an increased chance of side effects

• Liver disease—Patients with liver disease may have an increased chance of side effects if they use doxycycline or minocycline

Do not give tetracyclines to infants or children 8 years of age and younger unless directed by your doctor. Tetracyclines may cause permanently discolored teeth and other problems in patients in these age groups.

Tetracyclines should be taken with a full glass (8 ounces) of water to prevent irritation of the esophagus (tube between the throat and stomach) or stomach. In addition, most tetracyclines (except doxycycline and minocycline) are best taken on an empty stomach (either 1 hour before or 2 hours after meals). However, if TETRACYCLINE upsets your stomach, your doctor may want you to take it with food.

Do not take milk, milk formulas, or other dairy products within 1 to 2 hours of the time you take tetracyclines (except doxycycline and minocycline) by mouth. They may keep TETRACYCLINE from working properly.

If TETRACYCLINE has changed color or tastes or looks different, has become outdated (old), or has been stored incorrectly (too warm or too damp area or place), do not use it. To do so may cause serious side effects. Throw away the medicine. If you have any questions about this, check with your health care professional.

For patients taking the oral liquid form of TETRACYCLINE:

• Use a specially marked measuring spoon or other device to measure each dose accurately. The average household teaspoon may not hold the right amount of liquid.
• Do not use after the expiration date on the label since the medicine may not work properly after that date. Check with your pharmacist if you have any questions about this.

For patients taking doxycycline or minocycline:

• These medicines may be taken with food or milk if they upset your stomach.
• Swallow the capsule (with enteric-coated pellets) form of doxycycline whole. Do not break or crush it.

To help clear up your infection completely, keep taking TETRACYCLINE for the full time of treatment, even if you begin to feel better after a few days. If you stop taking TETRACYCLINE too soon, your symptoms may return.

TETRACYCLINE works best when there is a constant amount in the blood or urine. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times day and night. For example, if you are to take four doses a day, the doses should be spaced about 6 hours apart. If this interferes with your sleep or other daily activities, or if you need help in planning the best times to take your medicine, check with your health care professional.

Dosing—

The dose of these medicines will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules, tablets, or teaspoonfuls of suspension that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking a tetracycline.

For demeclocycline
• For oral dosage form (tablets):
  • For bacterial or protozoal infections:
    • Adults and teenagers—150 milligrams (mg) every six hours; or 300 mg every twelve hours. Gonorrhea is treated with 600 mg on the first day, then 300 mg every twelve hours for four days.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 1.65 to 3.3 mg per kilogram (kg) (0.8 to 1.5 mg per pound) of body weight every six hours; or 3.3 to 6.6 mg per kg (1.5 to 3 mg per pound) of body weight every twelve hours.
    • Infants and children 8 years of age and younger—Tetracyclines usually are not used in young children because tetracyclines can permanently stain teeth.

For doxycycline
• For oral dosage forms (capsules, suspension, and tablets):
  • For bacterial or protozoal infections:
    • Adults and children older than 8 years of age who weigh more than 45 kilograms (kg) (99 pounds)—100 milligrams (mg) every twelve hours the first day, then 100 mg once a day or 50 to 100 mg every twelve hours.
    • Children older than 8 years of age who weigh 45 kg (99 pounds) or less—Dose is based on body weight. The usual dose is 2.2 mg per kg (1 mg per pound) of body weight two times a day on the first day, then 2.2 to 4.4 mg per kg (1 to 2 mg per pound) of body weight once a day or 1.1 to 2.2 mg per kg (0.5 to 1 mg per pound) of body weight twice a day.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.
  • For the prevention of malaria:
    • Adults and teenagers—100 mg once a day. You should take the first dose one or two days before travel to an area where malaria may occur, and continue taking the medicine every day throughout travel and for four weeks after you leave the malarious area.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 2 mg per kg (0.9 mg per pound) of body weight once a day. You should take the first dose one or two days before travel to an area where malaria may occur, and continue taking the medicine every day throughout travel and for four weeks after you leave the malarious area.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.
• For injection dosage form:
  • For bacterial or protozoal infections:
    • Adults and children older than 8 years of age who weigh more than 45 kg of body weight (99 pounds)—200 mg injected slowly into a vein once a day; or 100 mg injected slowly into a vein every twelve hours the first day, then 100 to 200 mg injected slowly into a vein once a day or 50 to 100 mg injected slowly into a vein every twelve hours.
    • Children older than 8 years of age who weigh 45 kg of body weight (99 pounds) or less—Dose is based on body weight. The usual dose is 4.4 mg per kg (2 mg per pound) of body weight injected slowly into a vein once a day; or 2.2 mg per kg (1 mg per pound) of body weight injected slowly into a vein every twelve hours the first day, then 2.2 to 4.4 mg per kg (1 to 2 mg per pound) of body weight once a day, or 1.1 to 2.2 per kg (0.5 to 1 mg per pound) of body weight every twelve hours.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.

For minocycline
• For oral dosage forms (capsules and suspension):
  • For bacterial or protozoal infections:
    • Adults and teenagers—200 milligrams (mg) at first, then 100 mg every twelve hours; or 100 to 200 mg at first, then 50 mg every six hours.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 4 mg per kilogram (kg) (1.8 mg per pound) of body weight at first, then 2 mg per kg (0.9 mg per pound) of body weight every twelve hours.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.
• For injection dosage form:
  • For bacterial or protozoal infections:
    • Adults and teenagers—200 mg at first, then 100 mg every twelve hours, injected slowly into a vein.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 4 mg per kg (1.8 mg per pound) of body weight at first, then 2 mg per kg (0.9 mg per pound) of body weight every twelve hours, injected slowly into a vein.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.

For oxytetracycline
• For oral dosage form (capsules):
  • For bacterial or protozoal infections:
    • Adults and teenagers—250 to 500 milligrams (mg) every six hours.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 6.25 to 12.5 mg per kilogram (kg) (2.8 to 5.7 mg per pound) of body weight every six hours.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.
• For injection dosage form (muscle injection):
  • For bacterial or protozoal infections:
    • Adults and teenagers—100 mg every eight hours; or 150 mg every twelve hours; or 250 mg once a day, injected into a muscle.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 5 to 8.3 mg per kg (2.3 to 3.8 mg per pound) of body weight every eight hours; or 7.5 to 12.5 mg per kg (3.4 to 5.7 mg per pound) of body weight every twelve hours, injected into a muscle.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.

For tetracycline
• For oral dosage forms (capsules and suspension):
  • For bacterial or protozoal infections:
    • Adults and teenagers—250 to 500 milligrams (mg) every six hours; or 500 mg to 1 gram every twelve hours. Gonorrhea is treated with 1.5 grams as the first dose, then 500 mg every six hours for four days.
    • Children older than 8 years of age—Dose is based on body weight. The usual dose is 6.25 to 12.5 mg per kilogram (kg) (2.8 to 5.7 mg per pound) of body weight every six hours; or 12.5 to 25 mg per kg (5.7 to 11.4 mg per pound) of body weight every twelve hours.
    • Infants and children 8 years of age and younger—Tetracyclines are usually not used in young children because tetracyclines can permanently stain teeth.

Missed dose—

If you miss a dose of TETRACYCLINE, take it as soon as possible. This will help to keep a constant amount of medicine in the blood or urine. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store TETRACYCLINE:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the capsule or tablet form of TETRACYCLINE in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the oral liquid forms of TETRACYCLINE from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.