Dosage and Administration:
Ethambutol hydrochloride should not be used alone, in initial treatment or in retreatment. Ethambutol hydrochloride 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.
Ethambutol hydrochloride is not recommended for use in pediatric patients under thirteen years of age since safe conditions for use have not been established.
In patients who have not received previous antituberculous therapy, administer ethambutol hydrochloride 15 mg per kilogram (7 mg per pound) 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.
In patients who have received previous antituberculous therapy, administer ethambutol hydrochloride 25 mg per kilogram (11 mg per pound) 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 ethambutol hydrochloride administration, decrease the dose to 15 mg per kilogram (7 mg per pound) 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).
| 15 mg/kg (7 mg/lb) Schedule |
| Weight Range || Daily Dose |
| Pounds || Kilograms || In mg |
|Under 85 lbs||Under 37 kg||500|
|215 and Over||Over 97||1500|
| 25 mg/kg (11 mg/lb) Schedule |
|Under 85 lbs||Under 38 kg||900|
|219 and Over||Over 99||2500|