Cannabis-induced diffuse alveolar hemorrhage

Case Discussion

A young man presented to the ER with mild hemoptysis. He mentioned smoking cannabis regularly, the last instance being several hours before the hemoptysis started. He was cooperative and vehemently denied ever using any drug but cannabis. History also notable for cigarette smoking (1 pack year). Saturation was 93% in room air and diffuse wet crackles were auscultated over the lungs. The only abnormal blood test result was marked leukocytosis of 24.3 K/µL with 92% neutrophils. A urine drug panel was strongly positive for cannabis but not for any other recreational drug, including cocaine. After an initial chest x- ray showed mild ground glass opacities, CT chest was done. The physician in charge asked for non-contrast CT, since hemoptysis was mild, as were the rest of his symptoms. Following admission for observation, the hemoptysis stopped he was released home without requiring any special treatment.
Follow-up chest x-ray (not available) done several days later was normal.

Hemoptysis as an adverse drug reaction to cannabis smoking is very rare, reflected by the paucity of case reports. It can be expected to rise, though, owing to a rise in global cannabis use, both for medical indications and recreational use. Additionally, the concentration of tetrahydrocannabinol (THC), the active substance in confiscated cannabis has been shown to have doubled in recent years ¹.