Histrelin

This study was the first to investigate the colonic stability of 17 peptide molecules (insulin, calcitonin, glucagon, secretin, somatostatin, desmopressin, oxytocin, Arg-vasopressin, octreotide, ciclosporin, leuprolide, nafarelin, buserelin, histrelin, [D-Ser(4)]-gonadorelin, deslorelin, and goserelin) in a model of the large intestine using mixed human faecal bacteria. Of these, the larger peptides - insulin, calcitonin, somatostatin, glucagon and secretin - were metabolized rapidly, with complete degradation observed within 5 min. In contrast, a number of the smaller peptides - Arg-vasopressin, desmopressin, oxytocin, gonadorelin, goserelin, buserelin, leuprolide, nafarelin and deslorelin - degraded more slowly, while octreotide, histrelin and ciclosporin were seen to be more stable as compared to the other small peptides under the same conditions. Peptide degradation rate was directly correlated to peptide lipophilicity (logP); those peptides with a higher logP were more stable in the colonic model (R(2)=0.94). In the absence of human faecal bacteria, all peptides were stable. This study highlights the impact of the colonic environment - in particular, the gut microbiota - on the metabolism of peptide drugs, and identifies potential peptide candidates for drug delivery to the colon.

BACKGROUND: ;Gonadotropin-releasing hormone (GnRH) agonists are FDA approved for the treatment of precocious puberty. The therapy consists of histrelin acetate (Supprelin), a surgically implanted device, or Lupron injections. In recent years, the use of these agents has been extended to include the off-label treatment of children with normally timed puberty. Trends in the off-label use of GnRH agonists in children across the U.S. have not been previously described in the literature.;METHODS: ;We analyzed data on the use of Supprelin and Lupron reported to the Pediatric Health Information System (PHIS) from 2013 to 2016 to determine the trends in both the FDA-approved and off-label uses of these medications.;RESULTS: ;We identified a stable cohort of 39 children's hospitals administering GnRH agonist therapies from 2013 to 2016. During this period, the annual number of children treated with these medications for precocious puberty increased modestly, from 283 to 303; meanwhile, the fraction of children receiving therapy for an off-label indication more than doubled, from 12% (39 of 322 total patients) to 29% (125 of 428 total patients). Privately insured patients were more likely to be treated for an off-label indication (13%; 119 out of 883 patients) than Medicaid patients (8%; 58 out of 706 patients; χ;2;[1] = 10.

A limited number of small studies have assessed the efficacy of gonadotropin-releasing hormone agonists in the treatment of ovarian endometriomas. Most of these trials have not used quantitative measurements to evaluate the effects of therapy on disease resolution. The results available thus far suggest that nafarelin, buserelin, and histrelin offer modest degrees of efficacy, similar to that of danazol, in the management of patients with ovarian endometriotic cysts. Gonadotropin-releasing hormone agonists appear to be most efficacious when endometriomas are less than 1 cm in size.