Use of molnupiravir: A Danish nationwide drug utilization study.

PURPOSE: To describe utilization patterns, characteristics of users and prescribers of the new oral antiviral medication, molnupiravir, indicated for mild-to-moderate COVID-19.

METHODS: Using nationwide registries, we identified all Danish adults who filled a prescription for molnupiravir from December 16th, 2021, to August 31st, 2022. We described weekly incidence rates and patient characteristics over time, prescriber characteristics as well as time between molnupiravir initiation and a positive SARs-CoV-2 test. Patient characteristics were compared to matched, untreated SARS-CoV-2 positive reference groups.

RESULTS: By August 31st, 2022, 5847 individuals had filled a prescription for molnupiravir. The incidence rate gradually increased to 16 weekly prescriptions per 1000 RT-PCR SARS-CoV-2 positives. Users of molnupiravir were most often men (55% vs. 45% women). The majority (81%) had a positive RT-PCR SARS-CoV-2 test and few (2.9%) redeemed molnupiravir outside the recommended window of 5 days from the positive test result. Compared to matched, untreated SARS-CoV-2 positive reference groups, users of molnupiravir had a median age of 74 years versus 49 years, a higher proportion resided in a nursing home (12% vs. 1.5%) and had a higher number of comorbidities (median of 3 vs. 0); most commonly hypertension (38%), chronic lung disease (35%), diabetes (20%) and mood disorders (20%). General practitioners were the primary prescribers of molnupiravir (91%).

CONCLUSIONS: Molnupiravir was mainly prescribed by general practitioners to RT-PCR SARS-CoV-2 positive individuals who had a potentially increased risk of severe COVID-19. Though some off-label prescribing occurred, our study indicates a high level of adherence to contemporary guidelines.