Somatropin
Indications
Somatropin is used for:
Growth hormone deficiency, HIV-associated wasting or cachexia, Short bowel syndrome
Adult Dose
Growth Hormone Deficiency
Weight-based dosing
Not to exceed 0.004 mg/kg/day SC initially for 6 weeks; may increase up to 0.016 mg/kg/day maximum
Nonweight-based dosing
0.2 mg/day (0.15-0.3 mg/day range) SC initially; may increase every 1-2 months by 0.1-0.2 mg/day based on clinical response and/or serum IGF-I levels
Short-bowel Syndrome
0.1 mg/kg/day SC (rotating injection sites to avoid lipodystrophy) for 4 weeks; may increase up to 8 mg/day maximum; treatment exceeding 4 weeks not studied
HIV-associated Wasting or Cachexia
0.1 mg/kg/day SC at bedtime (rotating injection sites to avoid lipodystrophy) up to 6 mg/day;
Alternatively:
>55 kg: 6 mg/day SC
45-55 kg: 5 mg/day SC
35-45 kg: 4 mg/day SC
<35 kg: 0.1 mg/kg/day SC
Elderly: Lower doses may be required.
Child Dose
Growth Hormone Deficiency
0.024-0.034 mg/kg/day SC 6-7 days/week
Small for Gestational Age
Not to exceed 0.067 mg/kg/day SC
Nooman Syndrome With Growth Hormone Deficiency
Not to exceed 0.066 mg/kg/week SC
Turner Syndrome With Growth Hormone Deficiency
Not to exceed 0.067 mg/kg/day SC
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
High doses of corticosteroid may inhibit growth-promoting effects of somatropin.
Adverse Effects
Side effects of Somatropin :
Hypothyroidism, peripheral oedema; headache; muscle and joint pain; benign intracranial hypertension. Loss of glycaemic control in diabetics, New onset type 2 diabetes mellitus, Scoliosis, Hypoglycemia, Seizures, Pancreatitis, Exacerbation of psoriasis, Hematuria, Hematoma, Leukemia, Papilledema, Arthralgia, Hyperlipidemia, Otitis media, Ear disorders, Respiratory Illness, Urinary tract infection.
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.