Montelukast failed to reduce the duration of symptoms in outpatient adults with mild to moderate COVID-19 infections, according to a recent trial.

The Accelerating COVID-19 Therapeutic Interventions and Vaccines-6 randomized clinical trial evaluated the efficacy of montelukast in reducing symptom duration among outpatients with mild to moderate COVID-19 infections. Conducted across 104 U.S. sites between January and June 2023, the trial, published in JAMA Network Open, included 1,250 participants aged 30 years or older with confirmed SARS-CoV-2 infections. The participants were randomly assigned 1:1 to receive 10 mg of montelukast once daily or placebo for 14 days.

The primary endpoint was time to sustained recovery, defined as at least 3 consecutive days without symptoms. No statistically significant difference was observed between the montelukast and placebo groups, with a median time to recovery of 10 days in both groups (95% confidence interval = 10–11 days; adjusted hazard ratio [HR] = 1.02, 95% credible interval [CrI] = 0.92–1.12, P = .63). Secondary outcomes, including hospitalization or death and health care utilization events (hospitalizations, urgent care visits, or emergency department visits), also showed no statistically significant differences between groups. Hospitalization rates were 0.3% in both the montelukast and placebo groups, and health care utilization events occurred in 2.9% of participants in each group (adjusted HR = 1.01, 95% CrI = 0.45–1.84, P = .48).

Adverse events were rare, occurring in 0.5% of montelukast recipients and 0.3% of placebo recipients. No deaths were reported in either group.

Full disclosures can be found in the published trial.