MYAMBUTOL is indicated for the treatment of pulmonary tuberculosis. It should not be used as the sole antituberculous drug, but should be used in conjunction with at least one other antituberculous drug. Selection of the companion drug should be based on clinical experience, considerations of comparative safety, and appropriate in vitro susceptibility studies. In patients who have not received previous antituberculous therapy, ie, initial treatment, the most frequently used regimens have been the following:

MYAMBUTOL plus isoniazid

MYAMBUTOL plus isoniazid plus streptomycin.

In patients who have received previous antituberculous therapy, mycobacterial resistance to other drugs used in initial therapy is frequent. Consequently, in such retreatment patients, MYAMBUTOL should be combined with at least one of the second line drugs not previously administered to the patient and to which bacterial susceptibility has been indicated by appropriate in vitro studies. Antituberculous drugs used with MYAMBUTOL have included cycloserine, ethionamide, pyrazinamide, viomycin and other drugs. Isoniazid, aminosalicylic acid, and streptomycin have also been used in multiple drug regimens. Alternating drug regimens have also been utilized.

MYAMBUTOL should not be used alone, in initial treatment or in retreatment. MYAMBUTOL should be administered on a once every 24-hour basis only. Absorption is not significantly altered by administration with food. Therapy, in general, should be continued until bacteriological conversion has become permanent and maximal clinical improvement has occurred.

MYAMBUTOL is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.

Initial Treatment: In patients who have not received previous antituberculous therapy, administer MYAMBUTOL 15 mg/kg (7 mg/lb) of body weight, as a single oral dose once every 24 hours. In the more recent studies, isoniazid has been administered concurrently in a single, daily, oral dose.

Retreatment: In patients who have received previous antituberculous therapy, administer MYAMBUTOL 25 mg/kg (11 mg/lb) of body weight, as a single oral dose once every 24 hours. Concurrently administer at least one other antituberculous drug to which the organisms have been demonstrated to be susceptible by appropriate in vitro tests. Suitable drugs usually consist of those not previously used in the treatment of the patient. After 60 days of MYAMBUTOL administration, decrease the dose to 15 mg/kg (7mg/lb) of body weight, and administer as a single oral dose once every 24 hours.

During the period when a patient is on a daily dose of 25 mg/kg, monthly eye examinations are advised.

See Table for easy selection of proper weight-dose tablet(s).

Weight-Dose Table

Ethambutol hydrochloride Tablets USP

100 mg – round, convex, white, film coated tablets engraved E6 on one side are supplied as follows:

NDC 54879-001-01 - Bottle of 100
NDC 54879-001-00 - 10 Blister-packs x 10 tablets

400 mg – round, convex, white, scored, film coated tablets engraved with E to the left and 7 to the right of the score on one side are supplied as follows:

NDC 54879-002-01 - Bottle of 100
NDC 54879-002-00 - 10 Blister-packs x 10 tablets

Store at controlled room temperature 20° to 25°C (68° to 77°F).

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Manufactured for & Distributed by: STI Pharma, LLC Langhorne, PA 19047. Revised March 2013

Last reviewed on RxList: 3/8/2013
This monograph has been modified to include the generic and brand name in many instances.