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.
Initial Treatment
In patients who have not received previous antituberculous therapy, administer ethambutol hydrochloride 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 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 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
