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What Can Cause a False Positive Drug Test for THC?

by Amrutha Karuturi Marijuana

There are many prescription drugs that can affect the results of a drug test. This is why a drug testing site will ask you for information about the drugs you may be taking and the amounts at which you are taking them. To avoid a false positive, the lab drug testing technician needs to take into account the types of drugs you may have in your system for medical reasons and rule them out of the overall result. You may be surprised by the impact these drugs can have on your drug test outcome as many of these drugs have similar effects to illegal drugs and several prescribed drugs can cause a result that indicates you have THC in your system.

What is the Psychoactive Ingredient in Marijuana?

You are probably well aware of THC’s connection with marijuana use and may be confused by the idea that a prescription drug can give you a result for THC but yes this does sometimes happen. The drug Dronabinol (also known as Marinol) actually contains delta-9-tetrahydrocannabinol or THC and is used to boost the appetite in patients who are suffering the effects of chemotherapy and AIDS. Often these conditions result in a lack of appetite or a reduced desire to eat because of nausea and vomiting that can occur with these conditions. These are the only conditions that have FDA approval to be treated with Dronabinol and so this type of positive drug test result is less likely than other positive results for drugs such as amphetamines because it’s the only prescription drug that contains THC.

Ibuprofen False Positive THC

While there is some indication that use of pain relievers such as Advil (Ibuprofen) or Aleve (Naproxen) and other NSAIDs may also cause a false positive, many drug tests have been modified to rule out regular dose use of these drugs so these drugs shouldn’t produce a positive result unless you are taking larger doses. Unlike with many foods or nutritional supplements, you are highly unlikely to get a positive result for THC with anything besides Marinol. If you’ve read that there are other drugs that have the same result that comes from a source other than one that can be considered a reputable one (such as the FDA or SAMHSA), there’s a very good chance that the association is merely a rumor and therefore unlikely to have the same result.

Other Medications that Cause False Positive for THC

There are other drugs that are frequently listed as a cause of positive THC drug test result but none of them have been conclusively been proven to have this effect. Among these are Anaprox, Indocin, Nalfon, Ifenoprophen, Relafen, Lodine, Tolectin, Orudis, Voltaren, Naprosyn, Dolobid, Clinoril, Ansaid, Meclomen, and Protonix. You will need to talk to a doctor if you take any of these, to verify if there might be any effect on drug test results from these drugs. For the time being, none of them have been listed as causing a positive THC result. Moreover, many drug tests that get a positive result are checked using an alternate method to rule out some of the more common false positive issues.