Major adverse cardiac events with haloperidol: A meta-analysis

Haloperidol is a commonly used antipsychotic drug and a frequent source of medication safety alerts because of its listing as a "known risk" QT interval-prolonging medication (QTPmed). We aimed to summarize the high-quality literature on the frequency and nature of proarrhythmic major adverse cardiac events (MACE) associated with haloperidol.

We searched Medline, Embase, International Pharmaceutical Abstracts, and Cochrane Central for randomized controlled trials (RCTs) involving patients 18 years or older comparing haloperidol to placebo. The FDA-adapted MACE composite included death, non-fatal cardiac arrest, ventricular tachyarrhythmia including torsades de pointes, and seizure or syncope. Random-effects meta-analyses were performed with a treatment-arm continuity correction for single and double zero event studies.

84 RCTs (n = 12180, 46% female), 23.8% of trials reported mean or median ages of their participants to be older than 65 years with 37 (44.0%) involving participants with psychiatric diagnoses, and 50 (59.5%) including electrocardiograms. Median follow-up duration was 28.0 days (interquartile range [IQR]=51.0). There were 1144 events, of which 97.8% were deaths, with 22 ventricular arrhythmias and 3 seizures or syncope. There was no difference in MACE with exposure to haloperidol compared to placebo (risk ratio [RR] 0.93, 95% CI: 0.80-1.08; I2 = 0%). IV haloperidol was not associated with increased risk of mortality (n = 5873, RR: 0.88, 95%CI:0.72-1.08).

We did not find that haloperidol was arrhythmogenic or increased mortality in these largely short-duration trials. Further research to clarify actual clinical outcomes related to QTPmeds is important to inform safe prescribing practices.