Variation in heart rate after acute cannabis exposure

Abstract Smoking botanical cannabis often produces tachycardia. However, infrequent reports describe bradycardia, particularly with edibles, concentrates, and resins. We compared the rate of tachycardia in patients with acute cannabis exposures from ingestion versus inhalation and botanical versus resins/concentrates/edibles. Prospective data collection instrument inserted into the case notes of the Oregon/Alaska Poison Center over a 17-month period. We excluded cases without a recorded heart rate. 101 patients met inclusion/exclusion criteria. Patients who inhaled cannabis products were more likely than those who ingested cannabis to have tachycardia (84% v 59%; p = 0.024). Amongst ingestions, tachycardia was more frequent with cannabis edibles than resins/concentrates (63% v 40%; p = 0.044). Amongst resin/concentrate exposures, inhalation more often produced tachycardia than ingestion (90% v 40%; p = 0.014). There was no difference in frequency of tachycardia amongst children (<12 years; 48%; 12/25) or adolescents (12-18 years; 77%; 20/26) when compared to adults (>18 years; 66%; 33/50). Six percent of patients had bradycardia, and all had significant symptoms of cannabis toxicity. The effects of cannabis exposure on heart rate are variable. Tachycardia is less common after ingestion of cannabis. Bradycardia occurs rarely after cannabis exposure, is associated with severe symptoms, and occurs in all age groups.