Question: can benadryl cause a false positive for tricyclic antidepressants?
Answer: False-positive results may occur with the following drugs: Seroquel (quetiapine fumarate), Trileptal (oxcarbazepine), Benadryl (diphenhydramine) at toxic concentrations, Flexeril (cyclobenzaprine), Thioridazine, and Thorazine (chlorpromazine). No compliance statements are in use for this test.