ESPN The Magazine reports that driver Jeremy Mayfield tested positive for methamphetamines during a random drug screening May 1 at Richmond International Raceway. The magazine cited "two independent sources." ESPN’s Ryan McGee reports that court papers revealed that the suspended driver had taken a double dosage of over-the-counter allergy medication Claritin-D before the Richmond drug test. Mayfield said he also was taking prescription Adderall-XR to treat Attention Deficit Hyperactivity Disorder. A third drug turned up positive, but until now had not been identified.

According to the report:

ESPN The Magazine learned Monday evening that the unidentified drug was methamphetamines. Neither NASCAR nor Mayfield is allowed to comment because of the gag order. Mayfield’s attorneys contend that it was a false positive test reading, triggered by either a mixture of the two acknowledged drugs ingested or by poorly executed testing procedures. In their lawsuit filed May 29, Mayfield’s legal team targeted Nashville-based AEGIS Sciences, the corporation contracted by NASCAR to conduct the league’s random drug screenings, which were implemented for the first time this season. AEGIS, which also is under the gag order, is not allowed to comment on specifics of methamphetamine testing as it refers to the Mayfield case, but its Web site does list two methamphetamine-specific urine-based test procedures.

Sources: Meth triggered positive test (ESPN)