Nutropin

somatropin (recombinant)

(soe-ma-troe-pin) somatropinnutropin,

Nutropin

(trade name),

Nutropin AQ

(trade name)

Classification

Therapeutic: hormones
Pharmacologic: growth hormones
Pregnancy Category: C

Indications

Growth failure in children due to deficiency of growth hormone.Growth failure in children with idiopathic short stature (non-growth-hormone-deficient short stature).Short stature associated with Turner’s syndrome.Growth failure associated with chronic renal insufficiency.Growth hormone deficiency in adults as a result of pituitary disease, hypothalamic disease, surgery, radiation or trauma.

Action

Produce growth (skeletal and cellular).Metabolic actions include:

Increased protein synthesis,

Increased carbohydrate metabolism,

Lipid mobilization,

Retention of sodium, phosphorus, and potassium.

Somatropin has the same amino acid sequence as naturally occurring growth hormone and is produced by recombinant DNA techniques.Growth hormone enhances GI tract mucosal transport of water, electrolytes and nutrients.

Therapeutic effects

Increased skeletal growth in children with growth hormone deficiency.Replacement of somatropin in deficient adults.Increased bone density in adult growth hormone–deficient patients.

Pharmacokinetics

Absorption: Well absorbed.Distribution: Localize to highly perfused organs (liver, kidneys).Metabolism and Excretion: Broken down in renal cells to amino acids that are recirculated; some liver metabolism.Half-life: Subcut—3.8 hr.

Time/action profile (growth)

ROUTE	ONSET	PEAK	DURATION
IM, subcut	within 3 mo	unknown	12–48 hr

Contraindications/Precautions

Contraindicated in: Closure of epiphyses; Active neoplasia; Hypersensitivity to growth hormone or benzyl alcohol preservative; Acute critical illness (therapy should not be initiated) or respiratory failure; Diabetic retinopathy; Prader-Willi syndrome with obesity and respiratory impairment (risk of fatal complications; can be used only if growth hormone deficiency is documented).Use Cautiously in: Growth hormone deficiency due to intracranial lesion; Coexisting adrenocorticotropic hormone (ACTH) deficiency; Diabetes (may cause insulin resistance); Geriatric patients (↑ sensitivity, ↑ risk of adverse reactions; Thyroid dysfunction; Neonates (diluent contains benzyl alcohol and may cause fatal gasping syndrome); Pregnancy or lactation (safety not established).

Adverse Reactions/Side Effects

Cardiovascular

edema of the hands and feet

Endocrinologic

hyperglycemia
hypothyroidism
insulin resistance

Gastrointestinal

pancreatitis (life-threatening)

Local

pain at injection site
local lipoatrophy or lipodystrophy with subcutaneous use

Musculoskeletal

arthralgia

Interactions

Drug-Drug interaction

Excessive corticosteroid use (equivalent to 10–15 mg/m²/day) may ↓ response to growth hormone.

Route/Dosage

Subcutaneous (Children) Growth hormone deficiency or idiopathic short stature—0.3 mg/kg/week divided into daily doses. Pubertal patients with growth hormone deficiency may require up to 0.7 mg/kg/week.Chronic renal insufficiency—0.35 mg/kg/wk given as daily injections. Turner’s syndrome—up to 0.375 mg/kg/wk in 3–7 divided doses.Subcutaneous (Adults) initially 0.006 mg/kg daily; may be increased up to 0.025 mg/kg/day in patients <35 yrs or 0.0125 mg/kg in patients >35 yrs or 0.2 mg/day starting dose (without consideration of body weight) then gradually increase by 0.1–0.2 mg/day q 1–2 mo until clinical response achieved.

Availability

Nutropin

Powder for injection: 5-mg (15 units)/vial, 10-mg (30 units)/vial

Nutropin AQ

Solution for injection (AQ): 10 mg (30 units)/mL in 2-mL vial or 10 mg (30 units)/mL in 2–mL pen cartridge

Nursing implications

Nursing assessment

Growth Failure: Monitor bone age annually and growth rate determinations, height, and weight every 3–6 mo during therapy.
Lab Test Considerations: Monitor thyroid function prior to and during therapy. May decrease T⁴, radioactive iodine uptake, and thyroxine-binding capacity. Hypothyroidism necessitates concurrent thyroid replacement for growth hormone to be effective. Serum inorganic phosphorus, alkaline phosphatase, and parathyroid hormone may ↑ with somatropin therapy.
- Monitor blood glucose periodically during therapy. Diabetic patients may require ↑ insulin dose.
- Monitor for development of neutralizing antibodies if growth rate does not exceed 2.5 cm/6 mo.
- Monitor alkaline phosphatase closely in patients with adult growth hormone deficiency.

Potential Nursing Diagnoses

Disturbed body image (Indications)

Implementation

Rotate injection sites with each injection.
- Nutropin vials: Reconstitute 5-mg vial with 1–5 mL of diluent provided by manufacturer aiming the liquid against glass vial wall. Reconstitute 10–mg vial with 1–10 mL diluent. Do not shake; swirl gently to dissolve. Solution is clear; do not use solutions that are cloudy or contain a precipitate. Stable for 14 days when refrigerated; do not freeze.
- Nutropin AQ vials or pen cartridges: Solution should be clear upon removal from refrigerator. Allow solution to come to room temperature before injection. Do not use if cloudy. Stable when stored in refrigerator for 28 days after initial use.
- Pen cartridges allows for administration of a minimum dose of 0.1 mg to a maximum dose of 4 mg in 0.1 mg increments.
Subcutaneous: Injection volume should not exceed 1 mL.

Patient/Family Teaching

Instruct patient and parents on correct procedure for reconstituting medication, site selection, technique for subcut injection, and disposal of needles and syringes. Review dosage schedule. Parents should report persistent pain or edema at injection site.
Explain rationale for prohibition of use for increasing athletic performance. Administration to persons without growth hormone deficiency or after epiphyseal closure may result in acromegaly (coarsening of facial features; enlarged hands, feet, and internal organs; increased blood glucose; hypertension).
Advise patient and parent to notify health care professional immediately if symptoms of pancreatitis (severe abdominal pain) occur.
Emphasize need for regular follow-up with endocrinologist to ensure appropriate growth rate, to evaluate lab work, and to determine bone age by x-ray exam.
Assure parents and child that these dose forms are synthetic and therefore not capable of transmitting Creutzfeldt-Jakob disease, as was the original somatropin, which was extracted from human cadavers.

Evaluation/Desired Outcomes

Child’s attainment of adult height in growth failure secondary to pituitary growth hormone deficiency. Therapy is limited to period before closure of epiphyseal plates (approximately up to 14–15 yr in girls, 15–16 yr in boys).
Replacement of growth hormone in deficient adults.

Nutropin®

Somatropin Endocrinology A recombinant growth hormone–GH for treating growth failure associated with Turner syndrome, GH inadequacy, and chronic renal insufficiency before kidney transplantation. See Growth hormone.