Sermorelin (Growth Hormone-Releasing Hormone) for Growth Hormone Deficiency
Sermorelin should be administered at a dose of 30 micrograms/kg body weight once daily via subcutaneous injection at bedtime for treating growth hormone deficiency. 1
Mechanism of Action and Indications
- Sermorelin is a 29-amino acid analogue of human growth hormone-releasing hormone (GHRH) that specifically stimulates growth hormone secretion from the anterior pituitary 1
- It is used both diagnostically (to test for growth hormone deficiency) and therapeutically (to treat confirmed growth hormone deficiency) 1
- Sermorelin represents an alternative approach to direct growth hormone replacement by stimulating the body's natural production of growth hormone 1, 2
Dosing Recommendations
Therapeutic Use
- For treatment of growth hormone deficiency: 30 micrograms/kg body weight administered subcutaneously once daily at bedtime 1, 2
- Administration should be consistent and at the same time each day, preferably in the evening to mimic natural growth hormone secretion patterns 2
- Treatment should be continued long-term to achieve optimal growth outcomes, with data showing sustained efficacy for up to 36 months 1
Diagnostic Use
- For diagnosis of growth hormone deficiency: 1 microgram/kg body weight administered intravenously as a single dose 1
- This diagnostic test appears to have fewer false positives than other provocative tests for growth hormone deficiency 1
Monitoring and Follow-up
- Height velocity should be monitored every 3-6 months to assess treatment efficacy 2
- A good response is typically defined as an increase in height velocity of >2 cm/year from baseline 3
- Monitor bone age progression to ensure it does not advance disproportionately to height age 2
- Measure insulin-like growth factor 1 (IGF-1) levels periodically as a surrogate marker for growth hormone response 4
- Monitor glucose metabolism due to potential effects on insulin sensitivity 5
Expected Outcomes
- Mean height velocity typically increases from baseline of approximately 4 cm/year to 7-8 cm/year after 6-12 months of therapy 2
- Approximately 74% of children show a good response to sermorelin therapy within the first 6 months 2
- "Catch-up growth" is observed in the majority of growth hormone-deficient children 1
- Children with delayed bone age and height age tend to respond better to treatment 1
Safety Considerations
- Sermorelin is generally well-tolerated in both single intravenous doses and daily subcutaneous administration 1
- Most common adverse effects include transient facial flushing and pain at the injection site 1
- Monitor for potential effects on glucose metabolism, as growth hormone therapies may affect insulin sensitivity 5
- Unlike direct growth hormone administration, sermorelin has not been associated with excessive generation of IGF-1 2
- No significant adverse changes in general biochemistry or hormonal analyses have been reported 2
Clinical Pearls
- Sermorelin may be particularly beneficial for patients with growth hormone deficiency of hypothalamic origin 1
- Response to sermorelin correlates with previous response to human growth hormone therapy, suggesting similar efficacy patterns 3
- A pretreatment peak serum GH response above 30 mU/L during an intravenous GHRH test may predict a good growth response to sermorelin therapy 3
- The development of anti-GHRH antibodies has been observed in some patients but does not appear to adversely affect growth or GH responses 3
Limitations
- The effect of long-term sermorelin treatment on final adult height has not been fully determined 1
- Direct comparisons with somatropin (recombinant human growth hormone) suggest that sermorelin may produce somewhat smaller increases in height velocity 1
- Optimal dosing regimens may still need further refinement 3