Prevalence of Potential Drug Interactions With Direct-Acting Antivirals for COVID-19 Among Hospitalized Patients.

Purpose: Clinicians consider polypharmacy, comorbidities, and other factors including the potential for drug-drug interactions (DDIs) when evaluating therapeutic options for specific clinical diagnoses. Contemporary treatment for coronavirus disease 2019 (COVID-19) includes direct-acting antivirals (DAAs). We sought to characterize patients' characteristics, comorbidities, and medications received during their hospitalization for COVID-19 and quantify potential DDIs that clinicians consider in selecting appropriate DAAs.

Methods: Patients hospitalized with a primary diagnosis of COVID-19 between May 2020 and December 2022 from the PINC AI Healthcare Database were identified. Medications administered during the hospitalization with the potential to cause DDIs with nirmatrelvir/ritonavir, remdesivir, or molnupiravir (per the Emergency Use Authorization factsheet or package insert) were assessed. For DDIs with nirmatrelvir/ritonavir, medications are categorized as "Contraindicated," "Avoid Concomitant Use," or "Other DDIs" (includes recommendation for dose modification or clinical and laboratory monitoring). For remdesivir, coadministration with chloroquine phosphate and hydroxychloroquine sulfate was not recommended. For molnupiravir, no drugs are listed as having potential DDIs. In a subset of patients, a multivariable logistic regression model was used to examine the association between documented patient/hospital characteristics and the likelihood of being "Contraindicated" to receive nirmatrelvir/ritonavir.

Findings: Of the 788,238 patients hospitalized for COVID-19 in 920 hospitals, 53% were ≥ 65 years old, and 31% had Charlson Comorbidity Index (CCI) ≥ 3. During the study period, about half of the patients received medications categorized as "Contraindicated" (11%) and/or "Avoid Concomitant Use" (41%) with nirmatrelvir/ritonavir. The frequency of administered drugs was higher in those aged ≥ 65 years (68%), CCI ≥ 3 (78%), with high-risk underlying conditions (55%). About 1% of patients received medications that were not recommended to be coadmistered with remdesivir. Among a subset of patients hospitalized for COVID-19 in 2022, those who were older, had higher CCI, high-risk underlying conditions, severe hepatic impairment, Medicare insurance, and hospitalized in larger hospitals were significantly more likely to be categorized as "Contraindicated" when considering nirmatrelvir/ritonavir as a therapeutic option to manage COVID-19.

Implications: A significant proportion of patients hospitalized for COVID-19 receive medications for other conditions that have the potential to result in DDIs with DAAs; most predominantly with nirmatrelvir/ritonavir, a strong CYP3A enzyme inhibitor, fewer with remdesivir, and none with molnupiravir. Higher age and comorbidity burden were significantly associated with a higher likelihood of receiving medications that are "Contraindicated" with nirmatrelvir/ritonavir. In the evolving COVID-19 era, these findings provide insights into patients hospitalized for COVID-19, and the polypharmacy evaluations that clinicians may encounter when selecting among DAAs to manage COVID-19.