The U.S. Centers for Disease Control and Prevention reported a national shortage on Friday of 300 milligram tablets of isoniazid, an antituberculosis medication.
Illinois' tuberculosis program first notified the CDC's Division of Tuberculosis Elimination of the isoniazid shortage on November 16. Other programs in Wisconsin, Virginia, New York, Maryland, Indiana and California later reported difficulty in getting the tablets. Other programs found it difficult to obtain a commercially available anti-TB preparation that combines INH and rifampin.
INH and rifampin are the two most important drugs for the treatment of latent TB infection and TB disease. Patients take up to 11 tablets per day as part of a four drug regimen, including ethambutol and pyrazinamide. Fixed-dose combinations can minimize drug-resistant TB. A shortage of INH increases the daily tablet intake from 11 to 13 tablets for TB disease. An increase in the number of required tablets could decrease compliance and increase drug-resistance.
There are three U.S. suppliers of INH - VersaPharm, Sandoz and Teva. The Food and Drug Administration reported that Teva has a low inventory and possible backorder of INH because of a shipping delay. Sandoz reported a shortage of the active ingredient from its supplier and estimated that it can fill orders by late January. VersaPharm estimated that it can fill orders in December.
The FDA is collaborating with the CDC to ensure a continuous supply of anti-TB medication.