Adult Dosing
Growth hormone deficiency
- Start 0.33 mg/day (0.1 mL of reconstituted solution) SC for 6 days/wk. If needed, gradually increase the dose to a max of 0.66 mg/day after 4 weeks
- Alt: Start 0.2 mg/day (0.15-0.30 mg/day range) SC; may increase the dose by increments of 0.1-0.2 mg/day q1-2 months if required
Notes:
- Thighs are recommended as the preferred injection sites and the injection site should be rotated to avoid lipoatrophy
- Consider a lower starting dose and smaller dose titration in elderly patients
- 1 mg of somatropin is equivalent to approximately 3 IU
Pediatric Dosing
Growth hormone deficiency
- Recommended dose: 0.17-0.3 mg/kg/wk SC, divided equally and given daily or 6 days/wk
Growth failure associated with Turner syndrome
- Recommended dose: 0.375 mg/kg/wk SC, divided equally and given daily or 6 days/wk
Notes:
- Thighs are recommended as the preferred injection sites and the injection site should be rotated to avoid lipoatrophy
- 1 mg of somatropin is equivalent to approximately 3 IU
[Outline]
See Supplemental Patient Information
- Water for injection can be used as a diluent for reconstitution in case of patients with a known sensitivity to metacresol (diluent)
- Somatropin therapy increases the mortality in patients with acute critical illness due to complications following open heart surgery, abdominal surgery, acute respiratory failure, or those with multiple accidental trauma. The potential benefit of treatment continuation with somatropin in patients experiencing acute critical illnesses should be weighed against the potential risk
- Fatalities have been reported following therapy initiation in pediatric patients with Prader-Willi Syndrome who had one or more of the following risk factors: severe obesity, history of upper airway obstruction or sleep apnea, or unidentified respiratory infection
- Evaluate the patients with Prader-Willi syndrome for signs of upper airway obstruction and sleep apnea before treatment initiation with somatropin and interrupt therapy if these symptoms develop during treatment
- Somatropin is contraindicated for long-term treatment of pediatric patients who have growth failure due to genetically confirmed Prader-Willi syndrome
- Therapy should be directed by physicians who are well trained in the diagnosis and management of pediatric patients with growth hormone deficiency and Turner syndrome, or adults with childhood-onset or adult-onset growth hormone deficiency
- Somatropin therapy may decrease insulin sensitivity, especially at higher doses in susceptible patients; periodically monitor glucose levels in all patients treated with somatropin, particularly in those with risk factors for diabetes mellitus
- Patients with preexisting tumors or GHD secondary to an intracranial lesion should be monitored routinely for progression or recurrence of the underlying disease process
- Intracranial hypertension (IH) with papilledema, visual changes, headache, and other signs have been reported with somatropin therapy; perform funduscopic examination before initiating treatment to exclude preexisting papilledema, and periodically during the course of somatropin therapy
- Discontinue treatment if papilledema is observed by funduscopy and restart at a lower dose after IH-associated signs and symptoms have resolved
- Patients with Turner syndrome, chronic renal insufficiency, and Prader-Willi syndrome may be at increased risk for the development of IH
- Closely monitor patients with hypopituitarism (multiple pituitary hormone deficiencies), during somatropin treatment
- Evaluate thyroid function tests in patients with an inherently increased risk of developing autoimmune thyroid disease and primary hypothyroidism, prior to somatropin treatment and periodically thereafter. Start thyroid hormone replacement therapy or appropriately adjust the dose when indicated
- Patients should be monitored carefully for any malignant transformation of skin lesions
- Rotate the injection site of somatropin as it can cause tissue atrophy if administered subcutaneously at the same site over a long period of time
- Pediatric patients with the onset of a limp or complaints of hip or knee pain during somatropin therapy should be carefully evaluated, as slipped capital femoral epiphysis may occur more frequently in patients with endocrine disorders or in patients undergoing rapid growth
- Patients with a history of scoliosis who are treated with somatropin should be monitored for progression of scoliosis as somatropin increases growth rate. Scoliosis is commonly seen in untreated patients with Prader-Willi syndrome; hence, physicians should be alert to these abnormalities
- Therapy may be associated with increased risk of ear and hearing disorders. Therefore, patients with Turner syndrome should be evaluated carefully for otitis media and other ear disorders
- Closely monitor patients with Turner syndrome for cardiovascular disorders as they are at increased risk for these conditions
- Fluid retention may occur in adult patients during somatropin replacement therapy
- Serum levels of inorganic phosphorus, alkaline phosphatase, parathyroid hormone, and IGF-1 may increase during somatropin therapy
Caution: Use cautiously in
Supplemental Patient Information
- Inform patients and caregivers about the potential benefits and risks associated with somatropin therapy
- Recommend a puncture-resistant container for the disposal of used syringes and needles
Pregnancy Category:B
Breastfeeding: Safety unknown. Limited data indicate that exogenous somatropin is not expected to cause any adverse effects in breastfed infants. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 16 February 2011). Manufacturer advises caution.
