Collected data included age, gender, stimulant regimen (drug name, dose, frequency), indication and duration of use, prescriber name and specialty, prescribing origin of initial stimulant medication, and whether stimulant use predated military service. Monitoring of stimulant medications was assessed via UDS at least annually, query of the prescription drug monitoring program (PDMP) at least quarterly, and average time between follow-up appointments with stimulant prescriber.
Monitoring parameters were assessed from January 1, 2017 through June 30, 2018, as it was felt that the 6-month study period would be too narrow to accurately assess monitoring trends. Mental health diagnoses, ADHD diagnostic testing if applicable, documented SUD or stimulant misuse past or present, and concomitant central nervous system (CNS) depressant use also were collected. CNS depressants evaluated were those that have abuse potential or significant psychotropic effects and included benzodiazepines, antipsychotics, opioids, gabapentin/pregabalin, Z-hypnotics, and muscle relaxants.
Results
The majority of participants were male (168/200) with an average age of 43.3 years. Dextroamphetamine/amphetamine was the most used stimulant (48.5%), followed by methylphenidate (40%), and dextroamphetamine (10%). Lisdexamphetamine was the least used stimulant, likely due to its formulary-restricted status within this facility. An extended release (ER) formulation was utilized in 1 of 4 participants, with 1 of 20 participants prescribed a combination of immediate release (IR) and ER formulations. Duration of use ranged from 3 months to 14 years, with an average duration of 4 years (Table 1).
Nearly 40% of participants reported an origin of stimulant initiation outside of LVAHCS. Fourteen percent of participants were started on prescription stimulant medications while active-duty service members. Stimulant medications were initiated at another VA facility in 10.5% of instances, and 15% of participants reported being prescribed stimulant medications by a civilian prescriber prior to receiving them at LVAHCS. Seventy-four of 79 (93.6%) participants with an origin of stimulant prescription outside of LVAHCS reported a US Federal Food and Drug Administration (FDA)-approved indication for use. The majority (87%) of stimulant medications were prescribed by the mental health service, and 25% of initial stimulant prescriptions were written by a single mental health prescriber. Eleven percent of participants were prescribed stimulant medications by multiple specialties, and nearly all participants had > 1 stimulant prescriber over the course of their treatment. More than 10% of veterans had their stimulant medication discontinued by one prescriber and then restarted by another prescriber.
Stimulant medications were used for FDA-approved indications (ADHD and narcolepsy) in 69.5% of participants. Note, this included patients who maintained an ADHD diagnosis in their medical record even if it was not substantiated with diagnostic testing. Of the participants reporting ADHD as an indication for stimulant use, diagnostic testing was conducted at LVAHCS to confirm an ADHD diagnosis in 58.6% (78/133) participants; 20.5% (16/78) of these diagnostic tests did not support the diagnosis of ADHD. All documented indications for use can be found in Table 2.
As expected, the most common indication was ADHD (66.5%), followed by ADHD-like symptoms (9%), refractory depression (7%), and fatigue (5.5%). Fourteen percent of participants had ≥ 1 change in indication for use, with some participants having up to 4 different documented indications while being prescribed stimulant medications. Twelve percent of participants were either denied stimulant initiation, or current stimulant medications were discontinued by one health provider and were restarted by another following a prescriber change. Aside from indication for stimulant use, 90% of participants had at least one additional mental health diagnosis. The rate of all mental health diagnoses documented in the medical record problem list can be found in Table 3.
A UDS was collected at least annually in 37% of participants. A methylphenidate confirmatory screen was ordered to assess adherence in just 2 (2.5%) participants prescribed methylphenidate. While actively prescribed stimulant medications, PDMP was queried quarterly in 26% of participants. Time to follow-up with the prescriber ranged from 1 to 15 months, and 40% of participants had follow-up at least quarterly. Instance of SUD, either active or in remission, differed when searched via problem list (36/200) and prescriber documentation (63/200). The most common SUD was alcohol use disorder (13%), followed by cannabis use disorder (5%), polysubstance use disorder (5%), opioid use disorder (4.5%), stimulant use disorder (2.5%), and sedative use disorder (1%). Twenty-five participants currently prescribed stimulant medications had stimulant abuse/misuse documented in their medical record. Fifty-four percent of participants were prescribed at least 1 CNS depressant considered to have abuse potential or significant psychotropic effects. Opioids were most common (23%), followed by muscle relaxants (15.5%), benzodiazepines (15%), antipsychotics (13%), gabapentin/pregabalin (12%), and Z-hypnotics (12%).