Urine screens of patients prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD) show that nonadherence is common, and those who who do not adhere to their regimens show increased rates of illicit drug use compared with their compliant counterparts, new research indicates.
“What our results show are objective data to a subjective problem,” coauthor Patricia Woster, PharmD, of Ingenuity Health, in Baltimore, Maryland, told Medscape Medical News.
“Patient adherence is often assessed with methods such as refill records or patient self-reports, but these findings reflect objective data showing that in 32.9% of patients who are prescribed with a diagnosis of ADHD, the medication was not found.”
The research, presented at the annual meeting of the American Professional Society of ADHD and Related Disorders, involved urine samples of 4094 patients prescribed an amphetamine or methylphenidate medication for ADHD that were submitted to the Ameritox laboratory between July 1, 2014, and June 30, 2015.
Among the patients, 3199 (78.1%) were prescribed an amphetamine; 862 (21.1%) were prescribed methylphenidate; and 33 (0.8%) were prescribed both.
Overall, the data showed that the prescribed ADHD medication was not detected in the urine samples of 1348 (32.9%) patients.
Among patients who were nonadherent to their regimen, there were significantly higher rates of detection of nonprescribed opioids (ajusted odds ratio [aOR], 1.41; 14.3% vs 9.7%), benzodiazepines (aOR, 1.37; 8.9% vs 6.3%), tetrahydrocannabinol (THC) (aOR, 1.64; 20.7% vs 11.9%), and cocaine (aOR, 1.69; 1.7% vs 0.9%).
Overall, 38.7% of patients who were nonadherent to their ADHD drug regimen tested positive for illicit drug use, compared with 24.8% of patients who were adherent (aOR 1.71).
For patients prescribed amphetamines, the rate of nonadherence was higher in comparison with those prescribed methylphenidate (33.8% vs 27.8%; aOR, 0.76; 95% confidence interval [CI], 0.63 – 0.91).
The study further showed significant variation in nonadherence with respect to age groups, ranging from a high of 41.6% of patients aged 20 to 29 years (n = 800) to the lowest level of 24.4% ofpatients aged 60 years or older (n = 115; aOR, 0.34).
Nonadherence rates were similar between men and women (33.2% vs 32.7%). The rates in 2015 were similar to those in 2014 (31.3% vs 34.5%).
“The data also suggest that potential nonadherence to prescribed stimulant ADHD therapy is associated with the use of marijuana, nonprescribed opioids, and nonprescribed benzodiazepines,” the authors write.
The findings are consistent with previously reported evidence of nonadherence to ADHD drugs, the investigators note.
Additionally, evidence of ADHD drug diversion has been reported in numerous studies, including research published in 2014
Taken from http://www.medscape.com/viewarticle/858260.