5 responses to ““Can you prescribe me cannabis, doc?””

  1. Good topic important for primary care.

  2. Love the charts and approach.

  3. In Figure One there appears to be a typo in the Neuropathic Pain evidence summary box. The listed NNT for neuropathic pain is 3, which would actually imply it is the most effective pharmaceutical option. The listed reference, Allan et al 2018 guideline, contains absolute effect sizes and NNT estimates in table 1, which identifies the outcome of 30% improvement in neuropathic pain scale as providing an NNT of 11 or 14, depending on inclusion or exclusion of cancer studies. Either way, NNT 11 is very different effect size than NNT of 3, as 3 implies 33% of patients improve on drug over placebo, and 11 implies 9% of patients experience this improvement. Hopefully this typo can be easily fixed, as I suspect this algorithm will be used by many clinicians in the coming months.
    As a secondary comment, the NNT of 15 quoted for palliative pain is transcribed correctly, but the source reference specifically notes it as a Non Statistically Significant (NSS) finding, with Very low quality evidence, perhaps NSS could be added to indicate the tenuous nature of this estimate.

  4. Nice resources! A little proofreading to take this from good to great ;^) The previous commenter already pointed out the most important issue – NNT errors. There also seem to be some missing links within the flow chart itself – to the online modules and video?; and some redundant wording in this heading “Cannabis Sample Cannabis Prescription & Authorization”…
    I found this to be helpful and it may well be useful in practice.

  5. Thank you for this. I am giving a talk later this month on the use of cannabis in long term facilities as Interior Health has begun to accept patients’ use, and will definitely provide this as a resource.
    A few thoughts.
    1. The answer to why the research is unreliable is a bit sugar coated and does not mention the previously illegal nature of cannabis and how cannabis research was restricted. It wouldn’t hurt to mention that it is more difficult to study cannabis in Canada now than prior to legalization. I am the qualified investigator for an RCT of cannabis for PTSD symptoms and the hurdles are immense. https://www.cbc.ca/news/canada/manitoba/canada-cannabis-research-barriers-1.5326667
    2. Under “Strategies for safer cannabis use”, you suggest “Avoid inhaling”. This doesn’t generally produce the desired effect. I might suggest “Avoid smoking or vaping”.
    3. The side effects that you list for CBD come from the Epidiolex monograph, which recommends doses of 5-20 mg/kg/day. These doses, in excess of 500-1000 mg/day have been found to be associated with these complications. Given that the cost of CBD is approximately $0.1/mg, very few patients will be able to afford such doses. Few patients in my practice take more than 60 mg/day and I have not seen the degree of reported side effects that you are suggesting.
    4. There seems to be a typo above the “Sample Cannabinoid Prescription” where the arrows have been interchanged – “Dried Cannabis or Cannabis Oil” and “Nabilone or nabiximols”
    5. On the topic of nabiximols, this is an expensive way to get an equal mixture of THC and CBD to a patient via an alcohol-based vehicle that is notorious for causing buccal irritation. A number of licensed producers make an equivalent mixture of THC and CBD in a carrier oil that can also be delivered by buccal spray and is cheaper.
    6. Under suggested starting dose, “2-2.5 mg of CBD+/-THC” is a bit unclear. Dosage should be specified as the THC component, which is usually what causes most side effects. I would potentially start lower, at 1 mg THC, especially in elderly patients. My practice is to match this with at least as much CBD or more, as this has been speculated (little firm evidence) to decrease the “high” effect of THC.

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