Generic Myambutol is indicated for the treatment of pulmonary tuberculosis. It should not be used as the sole antituberculous drug, but should be used in conjunction with at least one other antituberculous drug. Selection of the companion drug should be based on clinical experience, considerations of comparative safety, and appropriate in vitro susceptibility studies. In patients who have not received previous antituberculous therapy i.e. initial treatment and the most frequently used regimens have been the following:



MYAMBUTOL plus ionized

MYAMBUTOL plus ionized plus streptomycin.

In patients who have received previous antituberculous therapy, mycobacterial resistance to other drugs used in initial therapy is frequent. Consequently, in such retreatment patients. Myambutol should be combined with at least one of the second line drugs not previously administrated the patient and to which bacterial susceptibility has been indicated by appropriate in vitro studies.Antituberculous drugs used with myambutol have included cycloserine,ethionamide,pyrazinamide,viomycin,and other drugs. Isoniazid, amino salicylic acid, and streptomycin have also been used in many drug regimens. Alternating drug regimens have also been utilized.

Contraindications

In patients who are known to be hypersensitive to this drug and in patients with known optic neuritis, unless clinical judgement determines that it may be used.

Precautions

Possible teratogenic potential in women capable to bearing children should be weighed carefully against the benefits of therapy. There are published reports of live woman who received the drug during pregnancy without apparent adverse effect upon the fetus. Not recommenders for use in children under 13 year of age, since safe conditions for use have not been established.

In patients, with decreased renal function reduce the dosage as determined by serum levels so generic Myambutol, since the main path of excretion of this drug is by the kidneys. Because this drug may have adverse effects on vision, physical examination should include ophthalmoscopy, finger perimerty, and testing of color discrimination. In patients with visual defects such as cataracts, recurrent inflammatory conditions of the eye, optic neuritis, and diabetic retinopathy, the evaluation of changes in visual acuity is more difficult, and care should be taken to be given to the relationship between benefits expected and possible visual deterioration since evaluation of visual changes is difficult. Periodic assessment of organ system functions, with renal, hepatic, and hematopoietic, should be made during long-term therapy.

Adverse Reactions

Generic Myambutol may produce decrease in visual acuity that appears to be due to optic neuritis and to be related to dose and duration of treatment. Effects are generally reversible when administration of the drug is discontinued promptly. In rare case recovery may be delayed for up to 1 year or more and the effect may possibly be irreversible in the cases.

Advise patients to report promptly to their physician any change of visual acuity. The change in visual acuity may be unilateral or bilateral; hence each eye must be tested separately and both eyes tested together. Perform testing of visual acuity before beginning myambutol therapy and periodically during drug administration, except it should be done monthly when a patient is on a dosage of more than 15 mg per kilogram per day. Snellen eye charts are recommended for testing of visual acuity. Studies have shown that there are definite fluctuations of one or two lines of the Snellen chart in the visual acuity of many tuberculous patients not receiving myambutol.