Ethambutol

Ethambutol hydrochloride tablets should not be used alone, in initial treatment or in retreatment. Ethambutol hydrochloride tablets 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 tablets are not recommended for use in pediatric patients under 13 years of age since safe conditions for use have not been established.

Initial Treatment:

In patients who have not received previous antituberculous therapy, administer ethambutol hydrochloride tablets 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 ethambutol hydrochloride tablets 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 ethambutol hydrochloride tablets administration, decrease the dose to 15 mg/kg (7 mg/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      15 mg/kg (7 mg/lb) Schedule  Weight Range  Daily Dose  Pounds    Kilograms  In mg  Under 85 lbs.    Under 37 kg  500  85 - 94.5    37 – 43  600  95 - 109.5    43 – 50  700  110 - 124.5    50 – 57  800  125 - 139.5    57 – 64  900  140 - 154.5    64 – 71  1000  155 - 169.5    71 – 79  1100  170 - 184.5    79 – 84  1200  185 - 199.5    84 – 90  1300  200 - 214.5    90 – 97  1400  215 and Over    Over 97  1500      25 mg/kg (11 mg/lb) Schedule  Under 85 lbs.    Under 38 kg  900  85 - 92.5    38 - 42  1000  93 - 101.5    42 - 45.5  1100  102 - 109.5    45.5 – 50  1200  110 - 118.5    50 – 54  .1300  119 - 128.5    54 – 58  1400  129 - 136.5    58 – 62  1500  137 - 146.5    62 – 67  1600  147 - 155.5    67 – 71  1700  156 - 164.5    71 – 75  1800  165 - 173.5    75 – 79  1900  174 - 182.5    79 – 83  2000  183 - 191.5    83 – 87  2100  192 - 199.5    87 – 91  2200  200 - 209.5    91 – 95  2300  210 - 218.5    95 – 99  2400  219 and Over    Over 99  2500