26.2 Growth Hormones and Suppressants

Growth Hormone Therapy

Growth hormone therapy uses recombinant human growth hormone (rhGH) to treat growth disorders in both children and adults. For pediatric patients, the goal is achieving normal adult height. For adults with growth hormone deficiency, therapy improves body composition, bone density, and overall quality of life. Nurses are central to this process: administering injections, tracking growth, monitoring for adverse effects, and educating patients on long-term adherence.

Key Characteristics and Actions of Growth Hormone Drugs

Somatropin is the most commonly prescribed form of rhGH. It works by binding to growth hormone receptors throughout the body, which triggers several downstream effects:

• Growth stimulation in bones and soft tissues
• Increased protein synthesis, supporting tissue repair and muscle development
• Lipolysis (breakdown of stored fat)
• Hepatic glucose production, which is why blood glucose monitoring matters during therapy

Somatropin is administered via subcutaneous injection, and dosing is individualized based on patient response and IGF-1 levels (insulin-like growth factor 1, the main mediator of growth hormone's effects in tissues).

In children, growth hormone therapy is used to normalize height in conditions such as Turner syndrome, Prader-Willi syndrome, Noonan syndrome, and idiopathic short stature. In adults, it treats adult-onset growth hormone deficiency, improving body composition, bone density, and cardiovascular risk factors.

Indications, Side Effects, and Contraindications

Indications:

• Pediatric growth hormone deficiency
• Turner syndrome, Prader-Willi syndrome, Noonan syndrome
• Idiopathic short stature
• Adult-onset growth hormone deficiency

Common side effects:

• Headache, muscle pain, joint pain
• Peripheral edema
• Carpal tunnel syndrome
• Insulin resistance (this is a direct consequence of growth hormone's effect on glucose metabolism)

Rare but serious side effects:

• Benign intracranial hypertension (pseudotumor cerebri): presents with severe headache, visual changes, and nausea. Report these symptoms immediately.
• Slipped capital femoral epiphysis: watch for new hip or knee pain, especially in pediatric patients. A child who develops a limp during therapy needs prompt evaluation.
• Scoliosis progression: particularly relevant in patients with pre-existing curvature

Contraindications:

• Active malignancy
• Acute critical illness (e.g., post-cardiac surgery, acute respiratory failure)
• Severe obesity with severe respiratory impairment (especially important in Prader-Willi syndrome patients)
• Active proliferative or severe non-proliferative diabetic retinopathy
• Hypersensitivity to somatropin or any formulation component

Nursing Considerations

1. Assess baseline growth and development: measure height, weight, and body proportions before initiating therapy and at regular intervals.
2. Monitor IGF-1 levels: dosage adjustments aim to keep IGF-1 within the normal range for the patient's age and sex. Levels above normal increase the risk of adverse effects.
3. Administer via subcutaneous injection: rotate injection sites (abdomen, thighs, upper arms) to prevent lipoatrophy or lipohypertrophy at repeated sites.
4. Monitor for side effects: ask about headaches, edema, and joint pain at each visit. Be alert for signs of benign intracranial hypertension (headache with visual changes and nausea).
5. Track blood glucose levels: growth hormone increases insulin resistance, so glucose monitoring is especially important in patients with diabetes risk factors or pre-existing glucose intolerance.
6. Collaborate with the multidisciplinary team: endocrinologists typically guide dosing decisions, but nurses are often the first to identify changes in growth patterns or emerging side effects.

Patient Education Points

• Adherence matters: growth hormone therapy requires consistent daily injections over months to years. Results are gradual, and missing doses slows progress.
• Injection technique: use a new needle for each injection, rotate sites, and allow refrigerated medication to reach room temperature before injecting. Proper storage (refrigerated, not frozen) preserves drug potency.
• When to call the provider: report persistent headaches, vision changes, new hip or knee pain, or swelling that doesn't resolve.
• Follow-up visits are not optional: regular appointments track growth velocity, IGF-1 levels, and treatment response. These visits guide dosage adjustments.
• Lifestyle support: a balanced diet and regular physical activity complement therapy. Adequate sleep also supports natural growth hormone release.
• Inform all healthcare providers about growth hormone therapy, as it can interact with glucocorticoids, thyroid hormones, and other medications. It may also affect perioperative management.
• Emotional support: growth disorders can affect self-esteem, especially in adolescents. Connect families with support groups or counseling resources when appropriate.