Standard Dosage for Pediatric Growth Hormone Deficiency
Genotropin (somatropin) dosage for children with growth hormone deficiency (GHD) starts at 0.16 to 0.24 mg/kg body weight per week, divided into daily subcutaneous injections. Providers adjust based on growth response, typically targeting 0.3 mg/kg/week maximum, not exceeding 1 mg/day.[1][2]
Dosage for Other Pediatric Conditions
- Turner Syndrome: 0.045 to 0.05 mg/kg/day.
- Prader-Willi Syndrome (PWS): 0.24 mg/kg/week, divided into 6 to 7 doses.
- Idiopathic Short Stature (ISS): Up to 0.47 mg/kg/week, divided daily.
- Small for Gestational Age (SGA): 0.48 mg/kg/week until height reaches genetic potential.[1][3]
Doses use specific Genotropin devices like MiniQuick or GoQuick pens, calibrated by body weight.
How Providers Adjust Doses Over Time
Treatment begins at the lower end, with IGF-1 levels and growth velocity checked every 3-6 months. Increases occur if growth lags (less than 2 cm/year post-1 year). Discontinue if no response after 6-12 months or upon growth plate closure.[2][4]
Factors Influencing Dosage
Younger children or those with higher body weight may need proportional scaling. Monitor for side effects like fluid retention or glucose intolerance, which prompt dose reduction. Always base on individual IGF-1, not exceeding adult norms.[1][3]
Why Exact Dosing Varies by Age and Weight
| Age Group | Typical Starting Dose (mg/kg/week) | Notes |
|-----------|------------------------------------|-------|
| Under 2 years (SGA) | 0.48 | Higher to catch-up growth |
| 2-12 years (GHD) | 0.16-0.28 | Weight-based, daily |
| Pre-pubertal (ISS) | 0.37-0.47 | Up to 0.067 mg/kg/day |
| Pubertal | Lower end, taper | Avoid accelerating closure |
Obesity reduces required dose; renal impairment needs caution.[2]
Common Side Effects at Pediatric Doses
Injection site reactions, headaches, or mild scoliosis occur in 10-20% of children. Rare risks include intracranial hypertension (reduce dose immediately) or slipped capital femoral epiphysis. Long-term cancer risk unproven but monitored.[4][5]
[1]: Genotropin Prescribing Information (Pfizer)
[2]: FDA Label for Genotropin
[3]: Endocrine Society Guidelines on GH Therapy
[4]: Novo Nordisk Growth Hormone Dosing Summary
[5]: Drugs.com Genotropin Dosage Guide