Generic Name

Alprolix

Mechanism

• Receptor binding: Alprolix binds to the growth hormone receptor (GHR) on target tissues.
• JAK2/STAT5 signaling: Ligand‑receptor interaction activates JAK2, which phosphorylates STAT5; p‑STAT5 translocates to the nucleus to up‑regulate GH‑responsive genes.
• IGF‑1 induction: Primary downstream effect is stimulation of insulin‑like growth factor‑1 (IGF‑1) production in the liver and local tissues, mediating mitogenic, anabolic, and glucogenic actions.
• Feedback regulation: Reduced serum IGF‑1 attenuates somatostatin release, thus sustaining GH bioavailability.

Pharmacokinetics

• Dose‑response: Linear up to 0.5 mg/kg; steady‑state achieved after 2–3 weeks of daily dosing.

Indications

• Growth hormone deficiency (GHD) in children (age < 18 y) and adults.
• Growth failure in children with Prader‑Willi syndrome.
• Short‑stature due to SHOX deficiency (in prepubertal children).
• Growth failure in children with chronic renal insufficiency and cystic fibrosis (off‑label).

Contraindications:
• Known hypersensitivity to somatropin or any excipient.
• Active malignancy (especially acromegaly, pituitary adenoma).
• Uncontrolled diabetes mellitus.

Warnings:
• Monitor for signs of intracranial hypertension (headache, visual disturbances).
• Watch for glucose intolerance in patients with pre‑existing metabolic disorders.

Dosing

• Children: 0.2–0.3 mg/kg/day, split into 2–3 injections, or 0.3–0.4 mg/kg per week (continuous infusion not used).
• Adults: 0.25–0.5 mg/day, typically once daily.
• Maximum: 1.5 mg/day (≈0.02 mg/kg for patients >90 kg).
• Reconstitution: If pre‑filled, reconstitute with the provided preservative‑free diluent until full suspension. Use a single‑use syringe; discard the vial if unused.
• Injection: Rotate sites (abdomen, upper arm, thigh). Use a 28–30 G needle; depth 5–8 mm.
• Storage: Refrigerate 2–8 °C; do not freeze. Store at room temperature only for 24 h immediately before administration.

Adverse Effects

Common (≤10 %)
• Injection‑site reactions (pain, erythema, induration)
• Headache, fatigue
• Peripheral edema
• Mild hyperglycemia

Serious (≤1 %)
• Intracranial hypertension (headache, papilledema)
• Acute glucose intolerance leading to type 2 DM
• Short‑term increased intracranial pressure in cranial tumors
• Hypersensitivity reactions (anaphylaxis)

Rare (<0.1 %)
• Osteoporosis with long‑term use
• Acromegalic changes with overdose

Monitoring

Endocrine panel (cortisol, TSH, free T4) may be assessed if clinically indicated.

Clinical Pearls

• Injection technique: Tilt the syringe 10–15°, inject smoothly to reduce local reactions; aspirate only if the medication contains preservatives.
• Self‑injection training: Patients and caregivers benefit from a 15‑minute demonstration session; repeat at each refilling visit.
• Dose titration: Increase by 0.05 mg/kg/2 weeks until IGF‑1 approaches mid‑range normal; avoid abrupt upward jumps that risk intracranial hypertension.
• Cold‑storage logistics: Use a portable cooler with a temperature monitor; never thaw and refreeze. Consider patient education about "just‑before‑dose" reconstitution.
• Co‑therapies: Avoid concurrent use of anabolic steroids or growth‑promoting agents without endocrinology supervision; they may confound IGF‑1 interpretation.
• Special populations: In patients with chronic liver disease, adjust dose less aggressively; liver function tests should be monitored for hepatotoxicity.
• Electronic health record integration: Set reminders for IGF‑1 checks 2 weeks post‑dose adjustment to expedite dose optimization.

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• *References available on request. This drug card is designed for quick reference by medical students and practicing clinicians.*