|Uses:||The uses of Myambutol include:|
MYAMBUTOL is indicated for the treatment of pulmonary tuberculosis, as shown by a large number of studies by investigators throughout the world. It has also been used successfully in cases of primary tuberculosis and extrapulmonary forms of tuberculosis, including miliary tuberculosis, tuberculous meningitis, tuberculosis of bones and joints, genitourinary tuberculosis, tuberculosis of the skin and tuberculous eye diseases. It should not be used as the sole anti-tuberculosis agent, but should be used in conjunction with at least one other antituberculosis treatment. Selection of the companion substance should be based on clinical experience, considerations of comparative safety and appropriate in vitro susceptibility studies.
In patients who have not received previous antituberculosis therapy, i.e. initial treatment, the most frequently used regimens have included three of the following agents - MYAMBUTOL, isoniazid, rifampicin and streptomycin - for the first 2-4 months.
MYAMBUTOL plus isoniazid plus rifampicin
or MYAMBUTOL plus isoniazid plus streptomycin
then continuing with a two agent regimen such as:
MYAMBUTOL plus isoniazid
or MYAMBUTOL plus rifampicin.
In patients who have received previous antituberculosis therapy, mycobacterial resistance to other substances used in initial therapy is frequent. Consequently, in such retreatment cases MYAMBUTOL should be combined with at least one of the second-line agents not previously administered to the patient and to which bacterial susceptibility has been indicated by appropriate in vitro studies. Antituberculosis agents used with MYAMBUTOL have included cycloserine, ethionamide, pyrazinamide, viomycin and other substances. Isoniazid, aminosalicylic acid and streptomycin have also been used in multiple treatment regimens. Alternating treatment regimens have also been utilised.
Dosage and Administration
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. In general, therapy should be continued until bacteriological conversion has become permanent and maximal clinical improvement has occurred.
In patients who have not received previous antituberculosis therapy, administer MYAMBUTOL 15 mg/kg 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 antituberculosis therapy, administer MYAMBUTOL 25 mg/kg of body weight, as a single oral dose once every 24 hours. Concurrently administer at least one other antituberculosis substance to which the organisms have been demonstrated to be susceptible by an appropriate in vitro test. Suitable substances 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 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.
An alternative method of administration, in both "initial treatment" and "re-treatment" cases, is to give the abovementioned daily dosage of 15 or 25 mg/kg/day for two months or longer, depending on the type and extent of disease and the bacteriological and roentgenographic response (or until at least one negative sputum is obtained). Thereafter MYAMBUTOL may be given in a dosage of 50 mg/kg twice weekly. When isoniazid is administered concomitantly, the usual dosage is 14 mg/kg twice weekly with 10 mg of pyridoxine for each 100 mg of isoniazid.
The usual daily dosage of isoniazid in adults is 300 mg, or 5 mg/kg on the basis of body weight. In children the usual daily dosage is 5 to 20 mg/kg.
Weight Dose Table for MYAMBUTOL Tablets
Weight Range 25 mg/kg Schedule Daily Dose in mg
Under 38 kg 900
Weight Dose Table for MYAMBUTOL Tablets
Weight Range15 mg/kg Schedule Daily Dose in mg
Under 37 kg 500
Over 97 1500