Rifampin is best taken with a full glass (8 ounces) of water on an empty stomach (either 1 hour before or 2 hours after a meal). However, if this medicine upsets your stomach, your doctor may want you to take it with food.

For patients unable to swallow capsules:

• Contents of the capsules may be mixed with applesauce or jelly. Be sure to take all the food to get the full dose of medicine.
• Your pharmacist can prepare an oral liquid form of this medicine if needed. The liquid form may be kept at room temperature or in the refrigerator. Follow the directions on the label. Shake the bottle well before using. Do not use after the expiration date on the label. The medicine may not work properly after that date. In addition, 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.

To help clear up your tuberculosis (TB) infection completely, it is very important that you keep taking this medicine for the full time of treatment, even if you begin to feel better after a few weeks. You may have to take it every day for as long as 1 to 2 years or more. It is important that you do not miss any doses.

Dosing

The dose of rifampin 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 rifampin. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules 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 rifampin.

• For oral dosage form (capsules) and injection dosage form:
  • For the treatment of tuberculosis (TB):
    • Adults and older children 600 milligrams (mg) once a day. Your doctor may instruct you to take 600 mg two times a week or three times a week. Rifampin must be taken with other medicines to treat tuberculosis.
    • Infants and children Dose is based on body weight and will be determined by your doctor. Rifampin is usually taken once a day. Your doctor may instruct you to take rifampin two times a week or three times a week. Rifampin must be taken with other medicines to treat tuberculosis.
  • For the treatment of patients in contact with the meningitis bacteria:
    • Adults and older children 600 mg once a day for four days.
    • Infants and children Dose is based on body weight and will be determined by your doctor.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. 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. If this medicine is taken on an irregular schedule, side effects may occur more often and may be more serious than usual. If you have any questions about this, check with your health care professional.

Storage

To store the capsule form of this medicine:

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

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 rifampin, the following should be considered:

Allergies Tell your doctor if you have ever had any unusual or allergic reaction to rifampin. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy Pregnant women with tuberculosis (TB) should be treated with TB medicines, including rifampin. Rifampin can rarely cause bleeding in newborn babies and mothers when taken during the last weeks of pregnancy. Studies in rats and mice have shown that rifampin given in high doses causes birth defects, usually backbone problems (spina bifida) and cleft palate.

Breast-feeding Rifampin passes into the breast milk. However, rifampin has not been reported to cause problems in nursing babies.

Children This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems in children than it does in adults.

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. Although there is no specific information comparing use of rifampin in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

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 rifampin, it is especially important that your health care professional know if you are taking any of the following:

• Acetaminophen (e.g., Tylenol) (with long-term, high-dose use) or
• Amiodarone (e.g., Cordarone) or
• Anabolic steroids (nandrolone [e.g., Anabolin], oxandrolone [e.g., Anavar], oxymetholone [e.g., Anadrol], stanozolol [e.g., Winstrol]) or
• Androgens (male hormones) or
• Antithyroid agents (medicine for overactive thyroid) or
• Carbamazepine (e.g., Tegretol) or
• Carmustine (e.g., BiCNU) or
• Chloroquine (e.g., Aralen) or
• Dantrolene (e.g., Dantrium) or
• Daunorubicin (e.g., Cerubidine) or
• Disulfiram (e.g., Antabuse) or
• Divalproex (e.g., Depakote) or
• Etretinate (e.g., Tegison) or
• Gold salts (medicine for arthritis) or
• Hydroxychloroquine (e.g., Plaquenil) or
• Isoniazid (e.g., INH, Nydrazid) or
• Mercaptopurine (e.g., Purinethol) or
• Methotrexate (e.g., Mexate) or
• Methyldopa (e.g., Aldomet) or
• Naltrexone (e.g., Trexan) (with long-term, high-dose use) or
• Phenothiazines (acetophenazine [e.g., Tindal], chlorpromazine [e.g., Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil], perphenazine [e.g., Trilafon], prochlorperazine [e.g., Compazine], promazine [e.g., Sparine], promethazine [e.g., Phenergan], thioridazine [e.g., Mellaril], trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin], trimeprazine [e.g., Temaril]) or
• Plicamycin (e.g., Mithracin) or
• Valproic acid (e.g., Depakene) These medicines may increase the chance of liver damage if taken with rifampin

• Anticoagulants (blood thinners) or
• Aminophylline (e.g., Somophyllin) or
• Amprenavir (e.g. Agenerase) or
• Antidiabetics, oral (diabetes medicine you take by mouth), or
• Chloramphenicol or
• Corticosteroids (cortisone-like medicine) or
• Delavirdine (e.g., Rescriptor) or
• Digitalis glycosides (heart medicine) or
• Disopyramide (e.g., Norpace) or
• Efavirenz (e.g., Sustiva) or
• Fluconazole (e.g., Diflucan) or
• Indinavir (e.g., Crixivan) or
• Itraconazole (e.g., Sporanox) or
• Ketoconazole (e.g., Nizoral) or
• Methadone (e.g., Dolophine) or
• Mexiletine (e.g., Mexitil) or
• Nelfinavir (e.g., Viracept) or
• Nevirapine (e.g., Viramune) or
• Oxtriphylline (e.g., Choledyl) or
• Quinidine (e.g., Quinidex) or
• Ritonavir (e.g., Norvir) or
• Saquinavir (e.g., Fortovase, Invirase) or
• Theophylline (e.g., Theo-Dur, Somophyllin-T) or
• Tocainide (e.g., Tonocard) or
• Verapamil (e.g., Calan) Rifampin may decrease the effects of these medicines

• Estramustine (e.g., EMCYT) or
• Estrogens (female hormones) or
• Oral contraceptives (birth control pills) containing estrogen or
• Phenytoin (e.g., Dilantin) Rifampin may decrease the effects of these medicines. If you are taking oral contraceptives, this may increase the chance of pregnancy. These medicines may also increase the chance of liver damage if taken with rifampin

• Alcohol abuse (or history of) or
• Liver disease There may be an increased chance of side effects affecting the liver in patients with a history of alcohol abuse or liver disease