- Hydroxychloroquine treatment carries increased risk for QTc prolongation in patients with COVID-19 pneumonia, according to the findings of this cohort study.
- Adding azithromycin to the regimen enhanced this risk.
Why this matters
- Editorial: treatment decisions for this disease will continue to be based on clinical judgment and, ideally, in the context of enrolling patients into clinical trials to provide definitive answers.
- 90 patients received hydroxychloroquine, and 53/90 also received azithromycin.
- 48.9% were female; mean age was 60.1 years.
- Mean BMI was 31.5 kg/m2.
- 53.3% had hypertension, 28.9% had diabetes.
- 26% were mechanically ventilated.
- Most were taking some QTc-prolonging medication.
- Baseline median QTc was 455 (interquartile range, 430-474) milliseconds.
- With hydroxychloroquine alone, this median was 473 (454-487) milliseconds with posttreatment QTc peak of 479.5 (443.5-501.5) milliseconds.
- With azithromycin added, it was 442 (427-461) milliseconds with posttreatment QTc peak of 458 (449-492) milliseconds.
- Changes in QTc on both treatments were significantly higher than with hydroxychloroquine alone, +23 (10-40) vs +5.5 (−14 to 31) milliseconds (P=.03).
- 7 patients on hydroxychloroquine alone had QTc that exceeded 500 milliseconds and was prolonged.
- 11 of those receiving both drugs had this outcome.
- Prolonged QTc was more likely with concomitant use of loop diuretics (P=.03) or baseline QTc ≥450 milliseconds (P=.008).
- 10 patients discontinued hydroxychloroquine treatment, including 1 who developed torsades de pointes.
- Cohort study at an academic center in Boston, Massachusetts.
- Funding: None disclosed.
- Causation not established.
- Higher-risk patients probably underrepresented.