Pharmacotherapeutic group: Somatropin is an endocrine hormone with metabolic and growth promoting effects.
Pharmacology: Pharmacodynamics: The major effects of Norditropin NordiLet are stimulation of skeletal and somatic growth and pronounced influence on the body's metabolic processes.
When growth hormone deficiency is treated, a normalisation of body composition takes place resulting in an increase in lean body mass and a decrease in fat mass.
Somatropin exerts most of its actions through IGF-I, which are produced in tissues throughout the body but predominantly by the liver.
More than 90% of IGF-I is bound to binding proteins (IGFBPs) of which IGFBP-3 is the most important.
A lipolytic and protein sparing effect of the hormone becomes of particular importance during stress.
Somatropin also increases bone turnover indicated by an increase in plasma levels of biochemical bone markers. In adults, bone mass is slightly decreased during the initial months of treatment due to more pronounced bone resorption, however, bone mass increases with prolonged treatment.
Pharmacokinetics: I.V. infusion of Norditropin (33 ng/kg/min for 3 hours) to nine growth hormone deficient patients gave the following results: Serum half-time of 21.1±1.7 min, metabolic clearance rate of 2.33±0.58 ml/kg/min and a distribution space of 67.6±14.6 ml/kg.