Safety Profiles, Pharmacokinetics, and Changes in Bone Turnover Markers After Twice-Weekly Subcutaneous Administration of Teriparatide in Healthy Japanese Postmenopausal Women: A Single-Blind Randomized Study.

Once-weekly injection of 56.5-μg teriparatide formulation is a potent therapeutic agent for osteoporosis treatment. However, this treatment has an issue of difficulty in continuing the treatment by its adverse side effects including nausea, vomiting, and headaches. To reduce these adverse side effects, we conducted a randomized, single-blind, placebo-controlled study to examine the pharmacokinetics, changes in bone turnover markers, and safety profiles of twice-weekly 28.2-μg teriparatide injections. Different dosing intervals of the twice-weekly 28.2-μg injections were also studied. A total of 100 healthy Japanese postmenopausal women were enrolled in this multiple-dosing study. The systemic exposure of teriparatide acetate in the twice-weekly 28.2-μg injection was half that of the once-weekly 56.5-μg injection. Changes in bone turnover markers in the twice-weekly 28.2-μg injection were comparable to those in the once-weekly 56.5-μg injection. Incidences of adverse events including nausea, vomiting, and headaches were lower in the twice-weekly 28.2-μg injections than those in the once-weekly 56.5-μg injection. Findings were similar in the twice-weekly 28.2-μg injections regardless of the dosing interval. Thus, the new dosing regimen using twice-weekly 28.2-μg injections maintained comparable efficacy to the once-weekly 56.5-μg injections; however, it improved the safety profile and contributed to better continuity of care with teriparatide.