False-positive drug test results have been reported in multiple drug classes. Some of the more common classes include:Antihistamines Antidepressants Antibiotics Analgesics Antipsychotics Decongestants Certain over-the-counter (OTC) drugsThe chart below identifies common substances reported to cause a false-...
Can I get a false positive? One study found high amounts of methamphetamine, MDMA and diphenhydramine (Benadryl), a common cutting agent in heroin, can cause a false positive. I educate my patients: If you're checking methamphetamines or MDMA for fentanyl with test strips, you only need to...