Abstract

We evaluated the efficacy of a depot preparation of growth hormone (GH) in a 15% gelatin solution (GH-gel) in the treatment of 15 growth hormone-deficient children. The studies were designed to see if prolonging absorption of GH to achieve lower more physiological concentrations of GH in plasma would decrease the frequency of injection, reduce the amount of GH needed for effective therapeutic response, and improve the response to long-term treatment. We found that after a single dose of GH-gel the plasma concentrations of GH were lower than those achieved after the standard aqueous preparation. The preparation was efficacious in promoting growth and our 1st study of 6 patients suggested that GH-gel given twice a week had a growth response equal to that of the three-times a week aqueous schedule. However both schedules resulted in the frequently observed decreased growth rate during the second treatment year. Our 2nd study, attempting to ameliorate this waning effect by using the GH-gel preparation twice a week in a weight-adjusted dose during the entire second year did not resolve the problem. Thus, GH in depot gel results in more physiological plasma concentrations of GH and may be beneficial in reducing the quantity of hormone needed and the injection frequency but it does not offer a solution to the waning response to the long-term administration of GH.