Cannabis every day?
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* Steven L. Shumak

In their article on cannabinoid hyperemesis syndrome (CHS),1 King and Holmes state that the syndrome occurs “in patients who have been using cannabis daily for years,” and that “patients with CHS have a history of daily use of natural or synthetic cannabis.” This implies that daily cannabis use is a prerequisite for CHS.

According to Simonetto and colleagues,2 59% of individuals with CHS report daily use of cannabis, with 25% using it no more than three times weekly, and some using it once a week.

Daily use of cannabis is not required for the development of CHS and, when clinically appropriate, should remain a diagnostic consideration even in relatively infrequent cannabis users.

## References

1.  King C, Holmes A. Cannabinoid hyperemesis syndrome. CMAJ 2015;187:355.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxODcvNS8zNTUiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTg3LzgvNjAyLjIuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  Simonetto DA, Oxentenko AM, Herman ML, et al. Cannabinoid hyperemesis: a case series of 98 patients. Mayo Clin Proc 2012;87:114–9.
    
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    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000300256100003&link_type=ISI)