GH therapy in adult GH deficiency: a review of treatment schedules and the evidence for low starting doses.

Recombinant human growth hormone (GH) has been licensed for use in adult patients with GH deficiency (GHD) for over 15 years. Early weight- and surface area-based dosing regimens were effective but resulted in supraphysiological levels of insulin-like growth factor-I (IGF-I) and increased incidence of side effects. Current practice has moved towards individualized regimens, starting with low GH doses and gradually titrating the dose according to the level of serum IGF-I to achieve an optimal dose. Here we present the evidence supporting the dosing recommendations of current guidelines and consider factors affecting dose responsiveness and parameters of treatment response. The published data discussed here lend support for the use of low GH dosing regimens in adult GHD. The range of doses defined as 'low dose' in the studies discussed here (~1-4 mg/week) is in accordance with those recommended in current guidelines and encompasses the dose range recommended by product labels.