Growth Hormone Therapy Side Effects
Growth hormone therapy is generally safe with rare but serious side effects including intracranial hypertension, slipped capital femoral epiphysis, and glucose metabolism alterations that require systematic monitoring every 3-6 months. 1, 2
Serious Side Effects Requiring Immediate Evaluation
Intracranial Hypertension
- Baseline fundoscopy must be performed before starting GH therapy 1, 2
- Occurs rarely but most commonly within the first 8-12 weeks of treatment 3
- Immediate evaluation is mandatory if persistent headache or vomiting develops 1, 2
- More common in children with growth hormone deficiency, Turner syndrome, or renal insufficiency 3
- GH therapy must be discontinued if intracranial hypertension occurs 2
Slipped Capital Femoral Epiphysis
- Any limping or complaints of hip or knee pain require immediate investigation 3
- Risk factors include childhood obesity and GH treatment itself 4
- Can occur both before and during GH therapy in susceptible populations 3
- Treatment must be stopped if this complication develops 2
Metabolic Side Effects
Glucose Metabolism Alterations
- Increased insulin secretion and hyperinsulinemia may occur during therapy 1, 2
- Close monitoring is essential, particularly in patients with obesity or diabetes risk factors 1
- Glucose intolerance can develop and requires regular surveillance 5
- Monitor serum glucose at every 3-6 month clinic visit 1, 2
Secondary Hyperparathyroidism
- May be unmasked or exacerbated by increased longitudinal bone growth 1
- Direct stimulatory effects on parathyroid gland or subtle effects on calcium/phosphate homeostasis 2
- Pre-existing renal osteodystrophy requires careful monitoring 1
- GH therapy should not be started if parathyroid hormone >500 pg/ml 4
- Persistent severe secondary hyperparathyroidism mandates treatment discontinuation 2
Common but Less Serious Side Effects
Injection Site Reactions
- Lipoatrophy at injection sites can occur 1, 2
- Prevented by rotating injection sites daily 1, 2
- Unlike adults, peripheral edema and carpal tunnel syndrome are rare in children 3
Musculoskeletal Effects
- Worsening of pre-existing scoliosis may occur 5
- Requires monitoring of skeletal maturation at regular intervals 1, 2
Absolute Contraindications
GH therapy must not be initiated in the following situations: 4
- Known hypersensitivity to GH or excipients 4, 1
- Active malignancy 4, 1
- Closed epiphyses 4
- Acute critical illness 4
- Proliferative or severe non-proliferative diabetic retinopathy 4
- Uncontrolled diabetes mellitus 1
- Pre-existing papilledema 1
- During the first year after renal transplantation 4
Required Monitoring Protocol
Clinic visits every 3-6 months must include: 1, 2
- Growth parameters and pubertal development 1, 2
- Skeletal maturation assessment 1, 2
- Thyroid hormone levels 1, 2
- Serum glucose 1, 2
- Calcium, phosphate, and bicarbonate 1
- Parathyroid hormone levels 1, 2
- Renal function 1
- Fundoscopy if any symptoms of intracranial hypertension 2
- Polysomnography before and 6-10 weeks after starting treatment in at-risk populations 2
Long-Term Safety Considerations
- Long-term registry data supports overall safety with similar adverse effects between GH-treated and control populations 1
- Both reference GH products and biosimilars have comparable safety profiles 1, 2
- Most children with GH deficiency do not have permanent deficiency and will not require adult treatment 6
- Increased risk for intracranial tumors has been reported in teenagers and young adults previously treated with cranial radiation 5
When to Stop Treatment
Discontinue GH therapy when: 2