Recombinant Somatropin
Indications
Recombinant Somatropin is used for:
Children's growth disorders, growth hormone deficiency,Turner syndrome, chronic renal failure, Prader-Willi syndrome, intrauterine growth retardation, severe idiopathic short stature
Adult Dose
Subcutaneous
Growth hormone deficiency
Adult: Initially, 6 mcg/kg daily. May increase gradually according to patient response. Max: 12.5 mcg/kg/day. Reassess 9 mth after starting treatment.
Elderly: Lower doses may be required.
Subcutaneous
HIV-associated wasting or cachexia
Adult: 0.1 mg/kg daily at bedtime. May be taken on alternate days for patients at increased risk of adverse effects. Max: 6 mg/day.
Short bowel syndrome
Adult: 100 mcg/kg/day for 4 wk. Max: 8 mg/day.
Child Dose
Subcutaneous
Growth hormone deficiency
Child: 25-35 mcg/kg daily. Reassess 9 mth after starting treatment.
Turner's syndrome; Growth retardation due to chronic renal insufficiency
Child: 45-50 mcg/kg or 1.4 mg/m2 daily.
Prader-Will syndrome; Growth retardation in children who were born small for gestational age
Child: 35 mcg/kg or 1 mg/m2 daily. Max: 2.7 mg daily.
Children with short stature homeobox-containing (SHOX) deficiency
Child: 50 mcg/kg/day may be used.
Renal Dose
Administration
Contra Indications
Acute critical illness due to heart or abdominal surgery, multiple accidental trauma or respiratory failure; active neoplasms, proliferative or preproliferative diabetic retinopathy; lactation; patients with closed epiphyses. Intracranial lesions. Patients with Prader-Willi syndrome who are severely obese or have severe respiratory impairment.
Precautions
Monitor thyroid function; benign intracranial hypertension. DM; may require dose reduction in insulin. Pregnancy. Discontinue treatment if there is evidence of tumour growth. Monitoring in patients with scoliosis is recommended due to risk of progression of scoliosis.
Pregnancy-Lactation
Pregnancy
Limited available data with somatropin use in pregnant women are insufficient to determine a drug-associated risk of adverse developmental outcomes
In animal reproduction studies, there was no evidence of fetal or neonatal harm when pregnant rats were administered SC somatotropin during organogenesis or during lactation at doses ~10-times higher than the maximal clinical dose of 0.016 mg/kg, based on body surface area
Diluent contains benzyl alcohol, which has been associated with gasping syndrome in neonates; the preservative benzyl alcohol can cause serious adverse events and death when administered intravenously to neonates and infants; if therapy needed during pregnancy, reconstitute with normal saline, use only one dose per vial, and discard reconstituted product after use, or use a benzyl alcohol-free formulation
Lactation
There are no data on presence of somatropin in human milk; limited published literature reports no adverse effects on breastfed infants with maternal administration of somatropin; no decrease in milk production or change in milk content during treatment with somatropin reported; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for somatotropin and any potential adverse effects on breastfed infant from therapy or from underlying maternal condition
Diluent contains benzyl alcohol; if therapy needed during lactation, reconstitute with normal saline, use only one dose per vial, and discard after use or use a benzyl alcohol-free formulation
Interactions
Concomitant corticosteroid therapy may inhibit the effect of somatropin. Gonadotropins, oestrogens, androgens & anabolic agents.
Adverse Effects
Side effects of Recombinant Somatropin :
Hypothyroidism, peripheral oedema; headache; muscle and joint pain; benign intracranial hypertension. Loss of glycaemic control in diabetics.
Mechanism of Action
Somatropin is a synthetic human growth hormone of recombinant DNA origin. It stimulates skeletal and soft tissue growth by promoting cell division, amino acid uptake and protein synthesis. It also possesses both insulin-like and diabetogenic effects.