Medications for attention-deficit hyperactivity disorder (ADHD) are prone to the same abuse, misuse, and diversion as opioids, research published in Drugs in R&D suggests.

Using a pharmacy database encompassing 65% of US retail dispensing across all types of pharmacies, researchers from Janssen Research & Development, LLC, studied nearly 4.5 million ADHD patients who were dispensed ADHD medications between February 1, 2011, and January 31, 2012, and just over 6 million asthma patients who were dispensed asthma medications in that same time period.

The researchers included all FDA-approved medications for ADHD, comprised of the stimulants amphetamine, dexmethylphenidate, dextroamphetamine, lisdexamfetamine, methamphetamine, and methylphenidate, as well as the non-stimulants atomoxetine, clonidine, and guanfacine.

The investigators used asthma medications as a comparator “because they are frequently used by a population with roughly similar demographic characteristics as the population using ADHD medications, including a large representation of children and young adults, and are not believed to be widely abused or diverted.”

The researchers then tracked the ADHD and asthma patients for 18 months to determine how many received potentially overlapping medications from different prescribers, as well as to calculate the number of prescribers and pharmacies involved in those transactions.

According to the study authors, an overlap occurred when 2 or more dispensings of medications from different prescribers were active on the same day, indicating a dispensed medication was used during the days’ supply of another filled prescription. When patients exhibited more than 1 overlap, the incident with the greatest amount of multiple dispensings was further examined.

The researchers discovered that overlapping medications from 2 or more prescribers dispensed by 3 or more pharmacies was 4 times more frequent in the ADHD study group than the asthma counterpart. Based on that finding, the investigators extrapolated that ADHD medication shopping was more prevalent among those who were dispensed drugs during the 4 months prior to the study period.

“The fact that the criteria that serve to identify subjects who engage in ADHD medication shopping behavior and opioid shopping behavior are similar seems to suggest that overlapping prescriptions written by different prescribers and filled at 3 or more pharmacies can be used as an operational definition to assess shopping behavior for medications that are prone to abuse and diversion in general,” the authors concluded. “It is worth noting that subjects abusing a specific drug are likely to abuse other drugs or have a higher risk of developing abuse when exposed to other medications with abuse potential.”

Unlike opioid shopping, in which only 0.5% of shoppers are aged 18 years or younger, shopping episodes for ADHD drugs most commonly occurred among those aged 10-39 years, 13% of whom were aged 10 years or younger.

Similar to opioids, however, a small proportion of ADHD medication shoppers were to blame for the majority of shopping behavior, as the 9.2% of subjects who shopped 6 times or more accounted for 42% of all shopping episodes.  

The researchers said they hope to use their data to understand why ADHD patients need to visit multiple pharmacies and prescribers, though they cited a survey of undergraduate students that found the leading source of ADHD drugs for nonmedical use was friends and peers.