Can taking Mucinex cause you to fail a drug test? (Answer Man)

Mucinex, an over-the-counter cough medication, may beat the snot out of congestion, and it might cause you to fail a drug screening.

“Generally, any over-the-counter medications that a person can take will not effect any of the testing,”Usha Brioughs, employee at Florida Drug Testing, said. “Unless it’s prescribed by the pharmacy, then they sometimes put additives to it that could render a positive result.”

The active ingredient in Mucinex is a drug called guaifenesin. An over-the-counter drug that assists in expectoration, which is the bringing up of phlegm from a person’s airways, guaifenesin was approved by the Food and Drug Administration in 1952 and is legal in the U.S.

“Of course, they make other products that contain gauifenisen that have other ingredients,“ CVS Pharmacist Keith Frierson said.

The manufacturer of Mucinex, Adams Respiratory Therapeutics, has an entire line of expectorant products, including a similarly named creation, Mucinex DM.

“Mucinex DM is gauifenisen, plus it has a decongestant,” Frierson said.

The DM ending stands for dextromethorphan, which is the pairing active ingredient to guaifenesin in Mucinex DM. More commonly referred to as DXM, dextromethorphan is an opioid agent used as a cough suppressant and can show up on a drug screening as opioids, opiates or heroin.

“That’s a restricted item (Mucinex DM),” Frierson said. “That’s why you have to sign for it and show valid identification.”

If you are genuinely sick, taking Mucinex DM, and are approached by your boss for random drug testing, it might feel like there’s no safe remedy.

However, the likelihood of testing positive for opioids from Mucinex DM consumption is even quite low. But, if you are lying to cover up heavy opioid or heroin abuse, you might want to think twice before blaming the failing grade on medicinal DXM use.

The 1995 study, “The dextromethorphan defense: dextromethorphan and the opioid screen” attempted to determine whether a single, oral dose of dextromethorphan produced a false positive urine opioid screen, may have discredited the dextromethorphan plea.

The randomized placebo-controlled study focused on 20 adult men who had no drugs in their systems before the test.

Each screen completed six hours after the participant had ingested a single dose of liquid medication, either dextromethorphan, codeine or placebo. Each participant ingested all three medications randomly, at least 72 hours apart.

Half of the participants ingested the standard adult dose of dextromethorphan, 20 mg, while the other half ingested double the adult dose. The amounts of codeine (30 mg) and sucrose placebo (10 mL) remained constant.

For these adults, whose calculated average age was a little over 30, all urine tests were negative for opioids and all other drugs.

Although DXM is legal, the study presents fairly conclusive evidence that it would be difficult to suggest medicinal use of DXM as an excuse for testing positive for opioids.

“I’ve never heard of Mucinex being abused,” Sarah Davis, a physician assistant at UNCA Asheville’s student health center, said.

This might prompt one to think there would be more public scrutiny about medicine residing on the shelves of any local drugstore that, on a drug screen, can pass as its cousins in the Schedule I drug classification, according to the Controlled Substances Act.

But this is where things get a little stuffy.

“DXM is not classified as a controlled substance,” Brioughs said. “It can be purchased legally in pharmacies, grocery stores and convenience stores.”

Some national pharmacies and wholesale distributors have chosen to regulate the sale of products containing DXM to only those over the age of 18. Also, limits on the quantity an individual may purchase have been instituted.

Currently, almost no stores inform customers of the betraying potentiality DXM possesses if taken before a drug screen. Although stores are not required to post such information, the cost of ignorance to a clogged up consumer can be a catch-22 of a headache.