ddI Warning: Don't Take Dapsone at Same Time

The U. S. Division of AIDS has issued a warning to physicians that patients using ddI and also using dapsone, a drug for pneumocystis prophylaxis, should not take the drugs within two hours of each other. The problem is that dapsone requires an acid environment in order to be dissolved; but ddI cannot tolerate an acid environment, so it is taken with a buffer to neutralize stomach acidity. The lack of acidity causes the dapsone not to be absorbed.

Jacobus Pharmaceutical Company, the manufacturer of dapsone, brought the problem to the attention of the Division of AIDS after several cases of pneumocystis were found in patients who were taking both drugs. At least 11 cases of pneumocystis have occurred within 10 to 130 days after starting therapy with the two drugs together.

This problem could also affect other drugs which require an acid stomach -- for example, ketoconazole. |

The following recommendation is included in Safety Memo 013 of the Division of AIDS:


"Recommendation: The Division of AIDS and Jacobus Pharmaceutical Company recommend that clinicians contact all patients who are receiving both ddI and dapsone by telephone and advise them to take dapsone two hours prior to ddI. "

kb The memo also says that if patients cannot take dapsone at least two hours before ddI, they should wait until two hours after. The two drugs should not be taken within two hours of each other.