I took a trazadone and i've heard it can cause a false positive for urine screens, i only took 50mg. how long before it's out of my urine completely?

5 x its half life: A drug is considered gone after about 5 half lives. Trazodone has a biphasic elimination with a redistribution of about one hour and an elimination of half-life of 10-12 hours. To be safe I would wait at least 50 hours and hydrate well before taking the urine drug test. Use of trazodone a triazolopyridine antidepressant can yield a false positive amphetamine result.