Marijuana and hydrocodone are two of the most widely used and abused drugs in the U.S. But according to a new study by one of the nation’s largest drug screening companies, chronic pain patients who are prescribed hydrocodone are less likely to take the painkiller if they are using marijuana.
Ameritox analyzed over 100,000 urine samples from patients nationwide who were prescribed hydrocodone, which is sold under the brand names Vicodin, Lorcet and Lortab. Hydrocodone is the most frequently prescribed drug in the country.
Nearly five million Americans use marijuana daily. Eighteen states and the District of Columbia have approved medical marijuana, which is used by many patients to reduce their pain and nausea.
Researchers found that 36.5% of the samples that tested positive for marijuana did not have the prescribed hydrocodone present. For patients who had no illicit drug detected, 29.7% had a negative test for hydrocodone use.
The difference appears small, but is significant to physicians. Not taking a prescribed drug is considered non-adherence or “misuse” by doctors.
“A clinician considering whether to test for marijuana should know that the data strongly suggests that marijuana use is associated with an increased risk of potential prescription drug non-adherence,” said Harry Leider, MD, Chief Medical Officer for Ameritox. “Evidence of marijuana use on a urine drug test can be as much of a red flag as a positive cocaine test that a patient’s use of prescription narcotics requires close monitoring.”
The research was presented at the American Academy of Pain Medicine’s annual meeting in Fort Lauderdale, Florida. It was not peer-reviewed. Ameritox, which has a vested interest in promoting drug tests, conducted the study.
“The results presented here suggest that for some, marijuana use is associated with misuse of prescription medications. Pain patients prescribed hydrocodone and using marijuana were missing their opioid and/or were found to be taking some other non-prescribed medicine significantly more often that those patients who were not using an illicit,” the study says.
“A high risk patient warrants more frequent follow-up, including the use of clinical tools such as prescription drug monitoring programs and more frequent urine drug testing.”
The Ameritox study is consistent with other research showing that about one in three urine samples contain no evidence of a prescribed pain medication – indicating that patients are reluctant to use painkillers, may not need the drugs, or that the drugs are being diverted and used by other people.