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Re: Cannabinoids as appetite stimulants

Ranged against the impressive array of endogenous appetite suppresants described by the author there is, not only ghrelin(1), but also the endogenous cannabinoid system, the orexigenic effects of the latter being purportedly mediated by cannabinoid receptors located in the hypothalamus(2). Just as ghrelin has been utilised for the purpose of stimulating appetite in anorexic cancer patients(3), and also in cachectic patients with chronic obstructive pulmonary disease(4), so might the cannabinoids be called upon to fulfil the same role, at least in carefully selected cases, given the demonstration, in the animal model, that cannabinoids stimulate appetite and increase food intake(5). Indeed, dronabinol, an oral form of delta 9-tetrahydrocannabinol, has been used in the treatment of anorexia and cachexia in HIV infection(6), and in the the control of nausea and vomiting complicating cancer chemotherapy(7).

Although mental confusion, emotional lability and hallucinations may complicate therepy with the cannabinoids(5), a placebo-controlled cross-over trial of dronabinolon in 15 patients with Alzheimer's disease resulted in an increase in body weight with euphoria and somnolescence as only occasional side effects(8). Assuming that the side effects might be dose-related, there might be room for pursuing the proposition by Berry and Marcus that treatment with the cannabinoids might be extended to the major problem of anorexia in the elderly(9)

References

(1) Hickson M Malnutrition and ageing Postgrad. Med. J. 2006:82:2-8.

(2) Cota D, Marsicano G, Tscip M, et al The endogenous cannabinoid system affects energy balance via central orexigenic drive and peripheral lipogenesis J. Clin. Invest. 2003:112:423-31.

(3) Neary NM, Small CJ, Wren CJ, et al Ghrelin increases energy intake in cancer patients with impaired appetite: acute, randomised placebo-controlled trial J. Clin. Endocrinol Metab. 2004;89:2832-6.

(4) NagayaN, Itoh T, Murakami S, et al Treatment of cachexia with ghrelin in patients with COPD Chest 2005;128:1187-93.

(5) Berry EM and Mechoulam R Tetrahydrocannabinoids in feeding and appetite Pharmacol and Therap 2002;95:185-90.

(6) Balog DS, Epstein ME, Amodio-Groton MI HIV wasting syndrome Ann Pharmacother 1998;32:446-58.

(7) Gonzalez-Rosales F and Walsh D Intractable nausea and vomiting due to gastrountestinal metastases releived by tetrahydrocannabinol(dronabinol) J Pain Symtom Manage 1997;14:311-4.

(8) Volicer L, Stelly M, Morris J, McLauglin CL and Volicer BJ Effects of dronabinol on anorexia and disturbed behaviour in patients with Alzheimer's disease Int J Geriatr Psychiatry 1997;12:913-19.