Can cannabis use lead to rhabdomyolysis?

Cannabis and Rhabdomyolysis: A Rare but Documented Association

Cannabis use can lead to rhabdomyolysis, though this is an uncommon complication that occurs through indirect mechanisms rather than direct muscle toxicity.

Documented Cases and Mechanisms

The association between cannabis and rhabdomyolysis exists primarily through secondary pathways rather than direct cannabinoid-induced muscle breakdown:

Hypokalemia-Induced Rhabdomyolysis

• Cannabis use has been associated with severe hypokalemia (potassium levels as low as 1.6 mmol/L), which can cause prolonged paralysis and immobilization leading to secondary rhabdomyolysis 1
• The proposed mechanism involves cannabinoid receptor 1 (CB1)-mediated activation of G protein-coupled inwardly rectifying potassium (GIRK) channels 1
• This pathway can result in rapidly progressing paresis of extremities, with rhabdomyolysis developing as a consequence of the prolonged immobilization 1

Cannabis Hyperemesis Syndrome (CHS) Complications

• Rhabdomyolysis can occur as a complication of cannabis hyperemesis syndrome, particularly in patients with long-standing heavy use (>4 times per week for over a year) 2
• One documented case involved a patient who developed rhabdomyolysis after 15 hours of continuous jogging while attempting to alleviate CHS symptoms 3
• Synthetic cannabinoid hyperemesis has been reported to cause rhabdomyolysis leading to acute renal failure 4

Heavy Cannabis Use and Acute Encephalopathy

• In heavy cannabis users (>10 joints/day), acute hippocampal encephalopathy has been documented with concurrent rhabdomyolysis, renal dysfunction, and inflammatory syndrome 5
• These cases involved bilateral hippocampal abnormalities on MRI and resulted in severe long-lasting memory impairment 5

Epidemiological Context

Among patients presenting to emergency departments with acute recreational drug toxicity:

• Cannabis was the third most common agent associated with rhabdomyolysis (15.8% of cases with rhabdomyolysis) 6
• However, only 2.4% of all drug toxicity presentations developed severe rhabdomyolysis 6
• There was a positive correlation between creatine kinase (CK) activity and creatinine concentration (r = 0.71), indicating kidney injury risk 6

Clinical Implications

Major guidelines on cannabis use do not list rhabdomyolysis as a primary adverse effect, focusing instead on cardiovascular effects (arrhythmias, orthostatic hypotension), cannabinoid hyperemesis syndrome, psychiatric complications, and hepatotoxicity with CBD use 2

Key Caveats:

• The absence of rhabdomyolysis from major 2024 ASCO and American College of Physicians cannabis guidelines suggests this is not a common or primary concern in clinical practice 7, 2
• When rhabdomyolysis does occur with cannabis, it appears to be through indirect mechanisms (severe electrolyte disturbances, extreme physical exertion during CHS, or prolonged immobilization) rather than direct muscle toxicity 1, 5, 3, 4
• Synthetic cannabinoids may carry higher risk than natural cannabis products 4

Monitoring Recommendations

In patients presenting with cannabis-related complications:

• Check serum potassium levels, particularly in those with weakness or paralysis 1
• Monitor creatine kinase in patients with prolonged immobilization, severe hyperemesis, or extreme compensatory behaviors 6, 3
• Assess renal function (serum creatinine) when rhabdomyolysis is suspected, as there is strong correlation between CK elevation and kidney injury 6
• Consider rhabdomyolysis in the differential diagnosis of heavy cannabis users presenting with acute encephalopathy and renal dysfunction 5