Patient-Level Medication Regimen Complexity in an Adolescent and Adult Population with Autism Spectrum Disorders

Adults with autism spectrum disorder (ASD) frequently experience polypharmacy. However, there is limited understanding of how to quantify medication complexity in this vulnerable population.

This study examined medication administration difficulty using the Medication Regimen Complexity Index (MRCI) tool in adolescents and adults with ASD. The outcomes compared the mean total MRCI score with the medication count, described MRCI contributions for over-the-counter medication (OTC), and compared MRCI scores by patient characteristics.

This was a retrospective chart review of patients aged 7-45 years (mean = 20.1) enrolled in a primary care ASD transitions program. Each patient's listed medications were counted and then scored using the validated MRCI tool.

For the 142 patients studied, mean total MRCI was 14.6 ± 14.6 (range 0-89) and mean medication count was 6.3 ± 5.4 (range 0-38). For patients on 0-4 medications (66 of 142; 46.5%), the mean MRCI was 5.5 ± 4.2, 5-9 medications (50 of 142; 35.2%) the mean MRCI was 15.2 ± 6.8, and 10-38 medications (26 of 142; 18.3%) the mean MRCI was 36.5 ± 18.9 (p<0.001). Sixty percent (85 of 142) reported OTC use, which contributed 26.6% to the mean total MRCI. Reported benzodiazepine (mean MRCI 25.8 ± 17.2), antiepileptic (mean MRCI 23.7 ± 16.9), antipsychotic (mean MRCI 19.7 ± 15.9), or antidepressant (mean MRCI 17.0 ± 14.8) use received higher MRCI scores compared to nonuse (p<0.001 for all except antidepressants [p=0.004]). Total MRCI did not differ significantly by age group, sex, or attention-deficit-hyperactivity disorder (ADHD) medication use (stimulant or nonstimulant).

Medication regimen complexity in adolescents and adults with ASD was increased significantly for individuals taking ≥ 5 medications. Central nervous system agent use, other than ADHD therapy, identified patients with higher regimen complexity. The related clinical effects of these findings warrant further investigation.