Perioperative Management of the Pediatric Patient of Medicinal Marijuana: What Anesthesiologists Should Know.

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This article is a review of the history, known pharmacology, current evidence and anaesthetic considerations relating to medicinal marijuana in children. The context of the review is centred on the perspective of the American Academy of Pediatrics.

There are 2 synthetic cannabinoids and 2 purified extracts in production but the only product approved by the FDA for use in children is cannabidiol which is a plant derived oral solution primarily used for refractory seizures, chronic pain, multiple sclerosis and cancer related pain or nausea and vomiting. The review identifies 2 cannabinoid receptors: CB₁ predominantly in the nervous system mediating psychoactive effects and CB₂ in the immune system thought to have anti-inflammatory and antineoplastic actions. Cannabidiol is a cannabinoid with potentiating effects and possible antagonism at CB₁ and CB₂ with sedating, antiepileptic and antiemetic properties without psychotropic effects. Medical use in children is usually oral or topical.

Anaesthetic considerations include:

1. Parental reassurance that the perioperative care team has a plan in place to minimise disruption of theory
2. Dronabinol, nabilone or cannabidiol appear safe to continue their perioperative dosage on the day of surgery and throughout their hospital course
3. Plant-derived cannabis products require individualised decisions about perioperative administration although in general most are safe to continue
4. Monitor for medication interactions such as heart rate abnormalities with the use of sympathomimetic drugs. Titrate sedative medications and opioids carefully to avoid excess sedation. Due to CYP3A4/2C9 metabolism drug interactions with other medications is possible and unpredictable.

Assessment of article

Given the limited scientific evidence available (only 5 paediatric RCTs: 1 related to epilepsy, 4 related to chemotherapy induced nausea and vomiting) and no long term studies the review offers a reasonable attempt to address a growing pharmaceutic area and its pragmatic impact. A general reassuring message of safety is conveyed with some helpful tables summarising product comparison and possible drug interactions.

Take home message

Medicinal marijuana, in particular Cannabidiol has a growing profile as a supplemental treatment for a small number of conditions which are challenging or refractory to conventional management options. It appears safe to continue through hospital stay but vigilance for drug interactions is recommended.

Reviewed by: Dr Tom Flett