Safety and Effectiveness of Hydroxychloroquine and Azithromycin Combination Therapy for Treatment of Hospitalized Patients with COVID-19: A Propensity-Matched Study

Introduction: We sought to determine the effectiveness and safety of hydroxychloroquine-azithromycin (HCQ-AZM) therapy in hospitalized patients with COVID-19.

Methods: This was a retrospective cohort study of 613 patients hospitalized (integrated health system involving three hospitals) for RT-PCR-confirmed COVID-19 infection between March 1, 2020 and April 25, 2020. Intervention was treatment with HCQ-AZM in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Outcomes of interest were in-hospital all-cause mortality, cardiovascular mortality, pulseless electrical activity (PEA) arrest, non-lethal arrhythmias, and length of hospital stay. Secondary measures included in-hospital corrected QT (QTc) interval parameters and serum biomarkers levels.

Results: Propensity-matched groups were composed of 173 patients given HCQ-AZM and 173 matched patients who did not receive treatment. There was no significant difference in in-hospital mortality (odds ratio [OR] 1.52; 95% confidence interval [CI] 0.80-2.89; p = 0.2), PEA arrest (OR 1.68, CI 0.68-4.15; p = 0.27), or incidence of non-lethal arrhythmias (10.4% vs. 6.8%; p = 0.28). Length of hospital stay (10.5 ± 7.4 vs. 5.8 ± 6.1; p < 0.001), peak CRP levels (252 ± 136 vs. 166 ± 124; p < 0.0001), and degree of QTc interval prolongation was higher for the HCQ-AZM group (28 ± 32 vs. 9 ± 32; p < 0.0001), but there was no significant difference in incidence of sustained ventricular arrhythmias (2.8% vs. 1.7%; p = 0.52). HCQ-AZM was stopped in 10 patients because of QT interval prolongation and 1 patient because of drug-related polymorphic ventricular tachycardia.

Conclusion: In this propensity-matched study, there was no difference in in-hospital mortality, life-threatening arrhythmias, or incidence of PEA arrest between the HCQ-AZM and untreated control groups. QTc intervals were longer in patients receiving HCQ-AZM, but only one patient developed drug-related ventricular tachycardia.