Which medication is known to cause a false positive result on the direct antiglobulin test?

The direct antiglobulin test (DAT), also known as the Coombs test, is used to detect antibodies that are bound to the surface of red blood cells. A false positive result can significantly affect clinical decisions and patient management. Penicillin is known to be associated with false positive results in the DAT because it has the ability to bind non-specifically to red blood cells, leading to the formation of immune complexes that can be detected by the test.

This phenomenon is notable with penicillin and its derivatives, where the drug can induce the production of antibodies against RBCs. In some cases, even after the medication is discontinued, the antibodies may persist, resulting in continued positive DAT results, complicating the interpretation.

In contrast, the other medications listed (Aspirin, Ibuprofen, and Cephalosporins) do not typically result in this kind of false positive in the direct antiglobulin test to the same degree or through the same mechanisms as penicillin. Understanding the specific interactions of penicillin with red blood cell antigens clarifies its unique role in this context.