Norditropin

somatropin, recombinant

Genotropin, Humatrope, Norditropin, Nutropin AQ, Nutropin AQ Pen, Nutropin Depot, Omnitrope, Saizen, Serostim, Tev-Tropin, Zomacton (UK), Zorbtive

Pharmacologic class: Posterior pituitary hormone

Therapeutic class: Growth hormone (GH)

Pregnancy risk category B (Genotropin, Saizen, Serostim), C

Action

Stimulates linear and skeletal growth, increases number and size of muscle cells, and influences internal organ size

Availability

Genotropin injection: 1.5 mg (about 4 international units/vial), 5.8 mg (about 15 international units/vial), 13.8 mg (about 41.4 international units/vial)

Humatrope injection: 2 mg (about 6 international units/vial), 5 mg (about 15 international units/vial), 6 mg (about 18 international units/vial), 12 mg (about 36 international units/vial), 24 mg (about 72 international units/vial)

Norditropin injection: 4 mg (12 international units/vial), 8 mg (24 international units/vial)

Norditropin injection cartridge: 5 mg/1.5 ml, 10 mg/1.5 ml, 15 mg/1.5 ml

Nutropin AQ injection: 10 mg

Nutropin AQ Pen injection cartridge: 10 mg

Nutropin Depot: 13.5-mg, 18-mg, and 22.5-mg single-use vials; 13.5-mg, 18-mg, and 22.5-mg kits

Nutropin injection: 5 mg (about 15 international units/vial), 10 mg (about 30 international units/vial)

Saizem injection: 5 g (about 15 international units/vial)

Serostim injection: 5 mg (about 15 international units/vial), 6 mg (about 18 international units/vial)

Tev-Tropin injection: 5 mg

Zorbtive injection: 8.8 mg in 10-ml vial

Indications and dosages

➣ Growth failure in children with inadequate endogenous GH

Children: 0.16 to 0.24 mg/kg (Genotropin) subcutaneously q week in six or seven divided doses. Or 0.18 mg/kg/week (Humatrope) subcutaneously or I.M., divided equally and given on three alternate days six times weekly (or daily, if epiphyseal closure hasn't occurred). Or 0.024 to 0.034 mg/kg (Norditropin) subcutaneously six or seven times each week using NordiPen injection pen. Or 0.3 mg/kg/week (Nutropin AQ, Nutropin AQ Pen, Tev-Tropin) subcutaneously in equally divided daily doses. Or 0.06 mg/kg (Saizen) subcutaneously or I.M. three times weekly.

➣ Endogenous GH replacement in adults with GH deficiency

Adults: 0.04 mg/kg/week (Genotropin) subcutaneously in six or seven divided doses. Or 0.006 mg/kg/day (Humatrope) subcutaneously. Or initially, no more than 0.006 mg/kg/day (Nutropin AQ, Nutropin AQ Pen, Tev-Tropin) subcutaneously; may increase to a maximum of 0.025 mg/kg daily in patients younger than age 35 or 0.0125 mg/kg/day in patients ages 35 and older. Or 0.005 mg/kg/day (Saizen) subcutaneously; may increase to a maximum of 0.01 mg/kg/day after 4 weeks, depending on patient tolerance.

➣ Short stature related to Turner's syndrome

Children: 0.375 mg/kg/week (Humatrope) subcutaneously, divided into equal doses given on 3 alternate days or daily. Or up to 0.375 mg/kg/week (Nutropin AQ, Nutropin AQ Pen) subcutaneously, divided into equal doses given three or seven times weekly.

➣ Idiopathic short stature (non-GH-deficient) in children whose epiphyses haven't closed

Children: Up to 0.37 mg/kg (Humatrope) subcutaneously q week. Divide dosage and give in equal doses six or seven times weekly.

➣ Growth failure in children with Prader-Willi syndrome

Children: 0.24 mg/kg/week (Genotropin) subcutaneously in six or seven divided doses

➣ Infants born small for gestational age

Children: 0.48 mg/kg/week (Genotropin) subcutaneously in six or seven divided doses

➣AIDS wasting or cachexia

Adults and children weighing more than 55 kg (121 lb): 6 mg (Serostim) subcutaneously at bedtime

Adults and children weighing 45 to 55 kg (99 to 121 lb): 5 mg (Serostim) subcutaneously at bedtime

Adults and children weighing 35 to 45 kg (77 to 99 lb): 4 mg (Serostim) subcutaneously at bedtime

Adults and children weighing less than 35 kg (77 lb): 0.1 mg/kg/day (Serostim) subcutaneously at bedtime

➣ Growth failure due to chronic renal insufficiency (up to time of kidney transplantation)

Children: Up to 0.35 mg/kg/weekly (Nutropin AQ, Nutropin AQ Pen) subcutaneously, divided into daily doses

➣ Short bowel syndrome in patients receiving specialized nutritional support

Adults: 0.1 mg/kg/day subcutaneously (Zorbtive), to a maximum of 8 mg/day for no more than 4 weeks

Contraindications

• Hypersensitivity to drug, benzyl alcohol, glycerin, or metacresol (with some diluents)

• Active neoplasia

• Acute, critical illness after open-heart surgery, acute respiratory failure, or multiple trauma

• Children with closed epiphyses

• Neonates (Zorbtive)

Precautions

Use cautiously in:

• hypothyroidism

• diabetes mellitus.

Administration

• Reconstitute by injecting supplied diluent through rubber top of vial and aiming liquid stream at side of vial. Swirl vial gently to mix; don't shake.

• Inspect reconstituted solution. Don't use if it has visible particles or is cloudy.

• Keep diluted drug refrigerated; use within 14 days.

• When using prefilled cartridges, follow manufacturer's instructions carefully.

• Know that patients receiving Zorbtive for short bowel syndrome may receive specialized nutritional support as needed.

Adverse reactions

CNS: headache, weakness

CV: mild and transient edema

GU: hypercalciuria

Hematologic: leukemia

Metabolic: fluid retention, mild hyperglycemia, hypothyroidism, ketosis

Musculoskeletal: localized muscle pain, tissue swelling, joint pain

Skin: rash, urticaria

Other: pain, inflammation at injection site

Interactions

Drug-drug. Androgens, thyroid hormone: epiphyseal closure

Corticotrophin, corticosteroids: inhibited growth response (with long-term use)

Drug-diagnostic tests. Alkaline phosphatase, glucose, inorganic phosphorus, parathyroid hormone: increased levels

Patient monitoring

• Monitor patient's height, X-rays, blood chemistry results, blood glucose level, and thyroid function studies.

See Watch for signs and symptoms of leukemia.

Patient teaching

• Advise patient and parents that regular check-ups and blood tests are needed to detect adverse reactions.

• Teach parents how to reconstitute and administer drug. Stress importance of following manufacturer's instructions carefully when using prefilled cartridges.

• Teach parents about proper handling and disposal of syringes, needles, and cartridges.

• As appropriate, review all significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.

somatropin (recombinant)

(soe-ma-troe-pin) somatropinnorditropen,

Norditropin

(trade name)

Classification

Therapeutic: hormones
Pharmacologic: growth hormones
Pregnancy Category: C

Indications

Growth failure in children due to deficiency of growth hormone.Children with short stature associated with Noonan syndrome or Turner syndrome.Children with short stature born small for gestational age with no catch-up growth by age 2–4 yr.Growth hormone deficiency in adults as a result of pituitary disease, hypothalamic disease, surgery, radiation, trauma, or childhood onset.

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.

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 phenol 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; Obstetric / 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

Adult Growth Hormone DeficiencySubcutaneous (Adults) 0.004 mg/kg/day, may be ↑ to 0.016 mg/kg/day after 6 wk or 0.2 mg/day starting dose (without consideration of body weight), then gradually ↑ by 0.1–0.2 mg/day q 1–2 mo until clinical response achieved.Pediatric Growth Hormone DeficiencySubcutaneous (Children) 0.024–0.034 mg/kg/day given 6–7 times weekly.Short Stature Associated with Noonan or Turner SyndromeSubcutaneous (Children) Noonan syndrome–Up to 0.066 mg/kg/day may be used; Turner syndrome–Up to 0.067 mg/kg/day may be used.Short Stature Born Small for Gestational AgeSubcutaneous (Children) Up to 0.067 mg/kg/day may be used.

Availability

Prefilled pens for injection (Nordiflex): 30 mg/3 mL (purple) Prefilled pens for injection (FlexPro): 5 mg/1.5 mL (orange), 10 mg/1.5 mL (blue), 15 mg/1.5 mL (green)

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.
- Nordiflex and FlexPro prefilled pens contain multiple doses. After initial injection, use within 4 wk if stored in refrigerator or within 3 wk if stored at room temperature.

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 dose 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).
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.
Advise parents to monitor blood glucose closely in children with diabetes mellitus. Parents should also be advised to report persistent severe abdominal pain; may be a symptom of pancreatitis.
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.

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.

Norditropin®

Somatropin Endocrinology A recombinant DNA product used for long-term treatment of children with growth failure due to inadequate endogenous pituitary GH. See Growth hormone.

Norditropin

A brand name for SOMATOTROPIN.