Anti-Nausea Medications for Cannabis Hyperemesis Did Not Cause Dangerous Heart Rhythm Changes | Research

The takeaway

Among 282 CHS patients treated in the emergency department, anti-emetic medications did not significantly prolong the QTc interval, though low potassium was a risk factor for dangerous QT prolongation.

Emergency physicians treating CHS; pharmacists reviewing anti-emetic safety; researchers studying CHS treatment protocols.

Only potassium below 3.0 mmol/L predicted QTc >500 ms

What the researchers found

No significant differences in post-medication QTc values were found between different anti-emetic drugs used to treat CHS. The only predictor of QTc prolongation above 500 ms was potassium below 3.0 mmol/L.

Why it matters

CHS patients often receive multiple anti-emetic medications, some of which are known to prolong the QTc interval. This study provides reassurance that these medications are relatively safe from a cardiac standpoint in CHS patients, as long as electrolytes are monitored.

The numbers in context

282 CHS cases identified. No significant QTc differences between medication types. Only potassium below 3.0 mmol/L predicted QTc prolongation above 500 ms in logistic regression.

How the study worked

Retrospective chart review of 282 CHS cases at the University of Colorado Health Emergency Department from January 2012 to December 2014. Identified by ICD9/10 codes for cannabis use. Chi-square tests, odds ratios, and logistic regression were used to analyze QTc prolongation by medication.

What this study cannot tell us

Retrospective design with cases identified by billing codes, which may miss or misclassify some cases. The study period (2012-2014) predates some newer CHS treatment approaches. Sample size may be insufficient to detect rare cardiac events.

How to read the evidence

Moderate: reasonably large retrospective cohort from a single academic center with specific cardiac monitoring data.

When this study was published

Published in 2022, covering cases from 2012-2014.

The bigger picture

CHS has become increasingly common, and emergency physicians need to know that standard anti-emetic treatments are cardiac-safe for these patients. The potassium finding makes clinical sense because CHS patients often have electrolyte depletion from persistent vomiting.

Questions still open

Should electrolyte monitoring be standard before administering anti-emetics to CHS patients? Are there specific anti-emetics that should be preferred in CHS patients with known electrolyte depletion?

Common questions

Are anti-nausea medications safe for CHS patients?

In this study, standard anti-emetics did not cause dangerous heart rhythm changes. However, patients with very low potassium (below 3.0) were at higher risk, so monitoring electrolytes remains important.

Why might CHS patients have low potassium?

CHS causes severe, repeated vomiting, which depletes electrolytes including potassium. This electrolyte loss, rather than the medications, was the main predictor of dangerous QTc prolongation.

Read the original research

QTc prolongation in cannabis hyperemesis syndrome patients exposed to antiemetics: A retrospective chart review.

The American journal of emergency medicine, 53, 285.e7-285.e8

View on PubMed ↗Publisher’s paper ↗

Citation

Noelle, Carrillo; Susan, Hammerman; Robert, Klemisch; Shelby, Shelton; Andrew, Monte. (2022). QTc prolongation in cannabis hyperemesis syndrome patients exposed to antiemetics: A retrospective chart review.. The American journal of emergency medicine, 53, 285.e7-285.e8. https://doi.org/10.1016/j.ajem.2021.09.048