medications that cause false positive
Substances/Conditions that can cause false positives for THC: 1  Dronabinol (Marinol) 2  Ibuprofen; (Advil, Nuprin, Motrin, Excedrin IB etc) 3  Ketoprofen (Orudis KT)  Kidney infection (Kidney disease, diabetes) Liver 1  Disease. Naproxen (Aleve)  Promethazine (Phenergan, 1  Promethegan) Riboflavin (B2, Hempseed  Oil)