Anterior Pituitary Hormones - Endocrinal Drug

ENDOCRINAL DRUG

Anterior Pituitary Hormones

Human Growth Hormone

It is used in the treatment of growth hormone-deficient chil-dren. Today, recombinant DNA technology is used to produce growth hormone (recombinant somatropin, somatrem, etc.).The usual mode of administration is subcutaneous injection, though it can also be given intramuscularly. Somatropin is a biosynthetic polypeptide hormone with an amino acid sequence identical to that of human growth hormone. Somatrem is a poly- peptide hormone derived from recombinant DNA technology. It has the identical sequence of 191 amino acids constituting pituitary-derived human growth hormone and an additional The commercial preparation is administered after reconstitu- tion with bacteriostatic water for injection, containing benzyl alcohol as an antimicrobial preservative. Benzyl alcohol has been associated with toxicity in newborns.

Recombinant growth hormone is used in adults to treat growth failure caused by growth hormone deficiency of either childhood- or adult-onset aetiology, chronic renal insufficiency in childhood, and Prader-Willi syndrome; for long-term treat- ment of short stature associated with Turner’s syndrome; and to treat AIDS-associated cachexia or weight loss.

Adverse Effects

·              Pain at the injection site.

·              Local lipoatrophy (subcutaneous injection).

·              Predisposition to diabetes mellitus, pancreatitis, hypo- and

·              hyperglycaemia.

·              Peripheral oedema.

·              Hypothyroidism.

·              Intracranial hypertension: Benign intracranial hypertension with papilloedema (visual changes, headache, nausea and vomiting) has been reported in several patients treated with growth hormone products. Symptoms usually occurred within the first 8 weeks of therapy and resolved upon discontinuation of the therapy, or a reduction of the growth hormone dose.

·              Carpal tunnel syndrome.

·              Gynaecomastia.

·              Increased alkaline phosphatase.

·              Local reactions at injection site including pain, numbness, redness, and swelling have occurred with somatropin and somatrem. Hyperglycaemia may occur with an acute over-dose. Symptoms of gigantism and/or acromegaly may be observed following long-term overdosage.

Prolactin

Prolactin is synthesised and secreted not only by the pituitary, but also by decidual cells in the terminal luteal phase of the menstrual cycle. It has no therapeutic value. On the other hand, excessive secretion of prolactin (hyperprolactinaemia) can cause problems such as galactorrhoea, amenorrhoea, and infertility in women, and impotence, gynaecomastia, and infer-tility in men. Causes of hyperprolactinaemia include disorders of hypothalamus or pituitary, renal failure, primary hypothy-roidism, and the use of dopaminergic antagonists.

Gonadotrophic Hormones (Glycoprotein Hormones)

These include luteinising hormone (LH), follicle stimulating hormone (FSH), and chorionic gonadotropin (CG). They are used in the treament of infertility and cryptorchidism. CG is helpful in the diagnosis of pregnancy, since the plasma and urine concentrations go up during this period.

Adverse effects include hyperstimulation of ovaries, increased tendency to abortion, and precocious puberty when CG therapy is undertaken in young boys for the treatment of cryptorchidism.