A safe cure for excessive appetite is a holy grail in pharmacology. Although gluttony is a much more pervasive problem that poor appetite, an effective cure for satiety is also needed. In the clinical setting, poor appetite remains a common problem with and without underlying problems. Treatments to this point, such as cyproheptadine or megestrol, may be useful in some patients. Better treatments are needed. One drug of interest is ghrelin (Cancer 2012; DOI: 10.1002/cncr.27430).
The introduction summarizes ghrelin’s biologic activity: “Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue receptor and is secreted predominantly by gastric endocrine cells. It induces dose-dependent, GH-releasing activity; stimulates appetite and food intake; and triggers a positive energy balance through a central mechanism involving hypothalamic neuropeptides.”
Plasma ghrelin levels decrease after gastric resection, helping to maintain weight loss. Therefore, the stomach may act as endocrine organ to maintain appropriate weight. Exogenous administration may increase appetite.
This cited article reports a prospective randomized placebo-controlled phase 2 study in which ghrelin was administered to 21 patients with esophageal cancer, receiving cisplatin-based chemotherapy; the dosage was 3 μcg/kg twice daily for 1 week. A placebo group (n=20) received saline. The ghrelin group consumed 18.2 kcal/kg/day compared with 12.7 kcal/kg/day. A measure of appetite, an appetite visual analog score, was also higher in the ghrelin-treated patients, 6.2 vs 4.1. Patients in the ghrelin group had fewer adverse effects of chemotherapy related to anorexia and nausea than patients in the control group. One patient receiving ghrelin stopped therapy because of excessive diaphoresis.
Although this medication is being studied in adult chemotherapy patients, down the road ghrelin and potential analogs may have a role in pediatric patients with a variety of disorders which inhibit their appetite.
- -Adachi S, Takiguchi S, Okada K, et al. Effects of ghrelin administration after total gastrectomy: a prospective, randomized, placebo- controlled phase II study. Gastroenterology. 2010;138:1312-1320.
- -NEJM 2002; 346: 1623-30, 1662. Plasma ghrelin levels decrease after gastric resection. Therefore, stomach may act as endocrine organ to maintain appropriate weight. However, ghrelin levels are reduced in obesity; so it is not clear that further reduction of these levels is clinically important.
- -Gastroenterology 2003; 125: 1492. Review of ghrelin.
- -Yamamoto K, Takiguchi S, Miyata H, et al. Randomized phase II study of clinical effects of ghrelin after esophagectomy with gastric tube reconstruction. Surgery. 2010;141:31-38.
- -Nakazato M, Murakami N, Date Y, et al. A role for ghrelin in the central regulation of feeding. Nature. 2001;409:194-198.
- -Kojima M, Hosoda H, Date Y, et al. Ghrelin is a growth-hormone- releasing acylated peptide from stomach. Nature. 1999; 402:656- 660.
- http://pennmedicine.adam.com/content.aspx?productId=16&pid=16&gid=50495 Review of cited article.