Can growth hormone (GH) be administered every other day in children with the same results?

Growth Hormone Administration Schedule in Children

Daily subcutaneous growth hormone administration is recommended for children rather than every other day dosing, as this is the standard regimen supported by clinical guidelines that has demonstrated optimal growth outcomes. 1

Evidence-Based Recommendations for GH Administration

The European Society for Paediatric Nephrology (ESPN) and other clinical guidelines clearly recommend that growth hormone should be administered at a dose of 0.045-0.05 mg/kg body weight per day via subcutaneous injections in the evening 1. This daily administration schedule has been the standard approach used in all randomized controlled trials that have demonstrated efficacy in improving growth outcomes in children.

Key aspects of the recommended administration protocol:

• Frequency: Daily subcutaneous injections
• Dosage: 0.045-0.05 mg/kg body weight per day
• Timing: Evening injections (to mimic physiological circadian rhythm of GH secretion)
• Administration site: Should be changed daily to avoid lipoatrophy

Rationale Against Every Other Day Administration

There are several important reasons why daily administration is preferred over every other day dosing:

1. Pharmacokinetics: GH has a relatively short half-life of 2-3 hours with peak levels (Tmax) occurring 3-6 hours after subcutaneous injection 1

2. Physiological mimicry: Daily evening administration better mimics the natural pulsatile secretion pattern of endogenous growth hormone

3. Evidence base: All randomized controlled trials demonstrating efficacy have used daily administration protocols 1

4. Established efficacy: The expected increase in final height after 2-5 years of daily GH treatment amounts to approximately 7.2 cm 1

Monitoring and Response Assessment

When administering GH therapy, regular monitoring is essential:

• Clinic visits every 3-6 months (more frequently for young patients)
• Monitor stature, height velocity, pubertal development, and skeletal maturation
• An adequate growth response is defined as height velocity during the first year of GH treatment greater than 2 cm per year over baseline 1

Potential Considerations for Alternative Dosing

While daily administration remains the standard, it's worth noting:

1. Research from 1983 showed that switching from 2-3 weekly intramuscular injections to daily subcutaneous injections significantly improved growth response in GH-deficient children 2

2. More recently, long-acting GH formulations (weekly administration) have been developed to potentially improve adherence, with some showing comparable or even superior efficacy to daily injections in specific patient populations 3, 4

3. Patient adherence can be a challenge with daily injections, though studies suggest this is less problematic in pediatric populations with growth disorders due to tangible effects and parental supervision 5

Conclusion

Based on the most recent and highest quality evidence, daily subcutaneous administration of growth hormone remains the standard of care for children requiring GH therapy. Every other day administration is not supported by current clinical guidelines or research evidence and may result in suboptimal growth outcomes due to the pharmacokinetic properties of GH.