Prescriptions Medications Used Before Diagnosis in Patients with Myotonic Dystrophy

Myotonic dystrophy (DM) is a rare, multisystem disease that causes myotonia, progressive muscle weakness, atrophy, and central nervous system dysfunction, and significantly affects quality of life (QOL) in patients. Citing a lack of evidence in “the DM patient experience before diagnosis,” J. Day, MD, PhD, and colleagues examined the prescription (Rx) use in patients with DM one year before their diagnosis. Their article, presented at AMCP 2022, where it was awarded a gold medal, reported 35 Rx categories with significantly higher use in patients with DM relative to non-DM matched controls.

These results supported the notion that “the DM diagnosis is complex and symptom management, on the journey to diagnosis, contributes to the cost and burden of DM to the patients and society,” stated Dr. Day.

The investigators reviewed PharmMetrics adjudicated claims from January 2010 through March 2021, from which they retrospectively included a total of 1,694 patients with DM type 1 or 2 and 8,470 controls matched for index month, age, region, gender, plan, and payer type. The Rxs dispensed among both cohorts over the 12 months prior to indexing date were compared based on 88 categories from the World Health Organization Anatomical Therapeutic Chemical (ATC) system class 2.

According to the report, significantly more patients with DM had a Charlson comorbidity index score ≥1 when compared to matched controls (19.1% vs. 9.7%). Among the 35 Rx categories with higher use in patients with DM, the greatest differences versus controls were seen in: systemic antibacterials (46.1% vs. 35.5%), ophthalmologicals (36.3% vs. 27.4%), intestinal anti-inflammatories (20.9% vs. 13.4%), acid-related disorders medications (15.5% vs. 8.8%), systemic corticosteroids (24.1% vs. 17.6%), and psychoanaleptics (20.8% vs. 14.5%). The study’s authors also identified the largest significant cost differences were in drugs used for diabetes ($357 vs $227, P = 0.0169), antiepileptics ($122 vs $32, P = 0.0054), and drugs for obstructive airway diseases ($219 vs $150, P = 0.0441).

Ultimately, Dr. Day and colleagues performed the real-world analysis to improve understanding of the characteristics of patients with DM. Their findings revealed an increased burden in both Rx cost and quantity prior to diagnosis, which could support a need for early screening of high-risk individuals.