With the advent of legalization in Canada, marijuana and marijuana-containing products are increasingly available to adult consumers. 

• Although marijuana is generally considered to be low risk, adverse effects can still occur.  The most common signs and symptoms of overconsumption include anxiety, paranoia, panic, tachycardia, confusion, dry mouth, and nausea and vomiting.
• Because of their delayed onset, individuals are far more likely to over-consume edible marijuana products.
• Children are particularly at risk from ingested cannabis products.
• Cannabinoid hyperemesis syndrome is the most significant acute complication of marijuana use.

• The majority of individuals who experience adverse reactions to cannabis can be managed with gentle, supportive care and reassurance only.  Symptoms are generally self-limiting and resolve gradually over a period of hours.
• Children who have consumed cannabis-containing products may develop significant and profound central nervous system depression.  Hyperkinesis may occur despite apparent coma.  Provide supportive care to these patients, ensuring a patent airway and effective oxygenation and ventilation. 
• Cannabinoid hyperemesis syndrome is a cyclical vomiting syndrome that occurs primarily in individuals who use significant quantities of cannabis, generally on a daily basis.  It involves a prodromal phase, where individuals feel vaguely unwell and mildly nauseated, followed by a hyperemetic phase with persistent nausea and vomiting.  People suffering from cannabinoid hyperemesis syndrome often report that hot water (bathing or showering) improves their symptoms; some evidence suggests that use of a capsicum cream rubbed on the abdomen may also attenuate the nausea.  Supportive care, including fluid replacement and anti-emetic medications, can be helpful; ultimately, cessation of cannabis use and time will allow symptoms to resolve.