Ethambutol

Adults: Ethambutol should never be used alone, whether it's initial treatment or retreatment. It should be given once every 24 hours only. Absorption is not significantly altered by taking it with food. In general, therapy should continue until bacteriological conversion has become permanent and maximal clinical improvement has occurred. Ethambutol is not recommended for pediatric patients under thirteen years of age, because safe conditions for use have not been established. Initial Treatment For patients who have not had antituberculous therapy before, give Ethambutol 15 mg/kg of body weight as a single oral dose once every 24 hours. In the more recent studies, isoniazid was given at the same time, as a single daily oral dose. Retreatment For patients who have already had antituberculous therapy, give Ethambutol 25 mg/kg of body weight as a single oral dose once every 24 hours. At the same time, give at least one other antituberculous drug to which the organisms have been shown to be susceptible by appropriate in vitro tests. Suitable drugs are usually those the patient has not used before. After 60 days of Ethambutol, reduce the dose to 15 mg/kg of body weight, still as a single oral dose once every 24 hours. During the period when a patient is on the daily dose of 25 mg/kg, monthly eye examinations are advised. Renal Impairment The dose may need adjusting, as determined by blood levels of ethambutol.