Hypocalcemic effects of rectal and intramuscular administration of synthetic salmon calcitonin

• Published in: International journal of clinical pharmacology, therapy, and toxicology Vol. 29; no. 8; p. 329
• Main Authors: Pagani, G, Pagani, M D, Gianola, D, Pedroncelli, A, Cortesi, L, Gherardi, F, Gualteroni, L, Tengattini, F, Montini, M
• Format: Journal Article
• Language: English
• Published: Germany 01-08-1991
• Subjects: Administration, Rectal; Adult; Biological Availability; Calcitonin - administration & dosage; Calcitonin - pharmacokinetics; Calcitonin - pharmacology; Calcium - blood; Female; Humans; Injections, Intravenous; Male
• ISSN: 0174-4879

To assess the acute biological activity of a new rectal form of synthetic salmon calcitonin (SMC), 10 healthy subjects were randomly assigned, according to a crossover design, to single doses of either 50 IU SMC intramuscularly or 100 IU SMC rectally. Ionized and total calcium were measured as SMC bioactivity indicators in blood samples collected during a 6-hour period after the administration of the drug. In all the subjects, rectal administration of 100 IU of SMC induced falls in both plasma total calcium and whole blood ionized calcium: similar levels were observed after intramuscular injection of 50 IU of SMC. The pharmacodynamic bioavailabilities for total and ionized calcium of the 100 IU suppository and the 50 IU intramuscularly were 106% and 60%. The total and ionized calcium AUCs were the same after i.m. injection and suppository. We conclude that, in normal subjects, synthetic salmon calcitonin administered by the rectal route at the dose of 100 IU is effective and has the same biological effects as 50 IU of SMC given intramuscularly. Therefore, this new rectal form may be a useful alternative to parenteral injection.