<p>Ethambutol is indicated for the treatment of&nbsp;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&nbsp;in vitro&nbsp;susceptibility studies. In patients who have not received previous antituberculous therapy, ie, initial treatment, the most frequently used regimens have been the following:</p>

<ul>
	<li>Ethambutol plus isoniazid</li>
	<li>Ethambutol plus isoniazid plus streptomycin.</li>
</ul>

<p>In patients who have received previous antituberculous therapy, mycobacterial resistance to other drugs used in initial therapy is frequent. Consequently, in such retreatment patients, Ethambutol should be combined with at least one of the second line drugs not previously administered to the patient and to which bacterial susceptibility has been indicated by appropriate&nbsp;in vitro&nbsp;studies. Antituberculous drugs used with Ethambutol have included cycloserine, ethionamide, pyrazinamide, viomycin and other drugs. Isoniazid, aminosalicylic acid, and streptomycin have also been used in multiple drug regimens. Alternating drug regimens have also been utilized.</p>