Growth hormone or somatotropin - Use and antagonists
Use
Growth hormone extracted from human pituitary glands is not marketed any more because it was at the origin of transmission of Creutzfeldt-Jakob disease. Now, only growth hormone obtained by recombinant DNA technique is available. It is administered by parenteral route.
Growth hormone is used in the treatment of delayed growth caused by growth hormone deficiency and some other causes, including the intra-uterine growth retardation not corrected spontaneously during the first 3 or 4 years after birth. Growth hormone should be prescribed by physicians experienced in endocrinology. If other hormonal deficiencies exist parallel to that of growth hormone, their correction is necessary.
Growth hormone was proposed as a protein anabolic in the elderly. However it was shown recently that growth hormone administered to seriously affected patients increased their mortality.
In a study of short duration growth hormone reduced the manifestations of Crohn's disease.
Growth hormone and IGF-1 are used in an illicit and dangerous way by body-building people to increase their muscular mass and by sportsmen to improve their performances. There is no documented evidence that this practice improves the performances of athletes who are in perfect health.
Among the adverse effects of growth hormone, one can quote development of antibodies, benign intracranial hypertension, lipoatrophias at the sites of injection, insulin resistance and a possible carcinogenicity.
Antagonists
To reduce the consequences of a hypersecretion of growth hormone as seen in acromegalic patients one can inhibit its secretion by dopaminergic or somatostatinomimetic drugs or inhibit the effects of growth hormone by inhibiting its receptors.
Pegvisomant, a structural analogue of growth hormone, inhibits its receptors to which it binds with high affinity. Pegvisomant (Somavert*) has a long duration of action because it is gradually released from a polyethylene glycol polymer. It is administered by subcutaneous route. Parallel to its clinical effects it reduces the levels of IGF-1.
Other antagonists of growth hormone and of IGF-1 are under development. It would be desirable to obtain orally active non-peptide antagonists.
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