Famprofazone
Famprofazone is a nonsteroidal [anti-inflammatory agent] of the pyrazolone series which is available over-the-counter in some countries such as Taiwan. It has analgesic, anti-inflammatory, and antipyretic effects. Famprofazone has been known to produce methamphetamine as an active metabolite, with 15–20% of an oral dose being converted to it. As a result, famprofazone has occasionally been implicated in causing positives on drug tests for amphetamines.