somatropin (recombinant)

BEERS REMS

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.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity to growth hormone or phenol preservative;
Closure of epiphyses;
Active neoplasia;
Acute critical illness secondary to complications of open heart surgery, abdominal surgery or trauma, or those with acute 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);
OB: Pregnancy.

Use Cautiously in:

Growth hormone deficiency due to intracranial lesion;
Pituitary hormone deficiency or hypoadrenalism;
Diabetes (may cause insulin resistance);
Thyroid dysfunction;
Lactation: Safety not established in breastfeeding;
Pedi: Childhood cancer survivors (↑ risk of intracranial tumors);
Geri: Appears on Beers list. ↑ risk of edema, arthralgia, carpal tunnel syndrome, gynecomastia, and impaired fasting glucose in older adults. Avoid use in older adults, except for confirmed growth hormone deficiency due to an established etiology.

Adv. Reactions/Side Effects ⬆ ⬇

CV: edema of the hands and feet

Endo: hyperglycemia, hypothyroidism, insulin resistance

GI: PANCREATITIS

Local: pain at injection site, local lipoatrophy or lipodystrophy

MS: arthralgia

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

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

Availability ⬆ ⬇

Solution for injection (prefilled pens): 5 mg/1.5 mL (orange); 10 mg/1.5 mL (blue); 15 mg/1.5 mL (green); 30 mg/3 mL (purple)

Route/Dosage ⬆ ⬇

Adult Growth Hormone Deficiency

SC (Adults ): 0.004 mg/kg/day, may ↑ 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 every 1–2 mo until clinical response achieved.

Pediatric Growth Hormone Deficiency

SC (Children ): 0.024–0.034 mg/kg/day given 6–7 times weekly.

Short Stature Associated with Noonan or Turner Syndrome

SC (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 Age

SC (Children ): Up to 0.067 mg/kg/day may be used.

US Brand Names ⬆ ⬇

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.

Classifications ⬆ ⬇

Therapeutic Classification: hormones

Pharmacologic Classification: growth hormones

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed.

Distribution: Localize to highly perfused organs (liver, kidneys).

Metabolism/Excretion: Broken down in renal cells to amino acids that are recirculated; some liver metabolism.

Half-Life: 3.8 hr.

Canadian Brand Names ⬆ ⬇

Norditropin Nordiflex

Time/Action Profile ⬆ ⬇

(growth)

ROUTE	ONSET	PEAK	DURATION
SUBQ	within 3 mo	unknown	12–48 hr

Patient/Family Teaching ⬆ ⬇

Instruct patient and parents on correct procedure for reconstituting medication, site selection, technique for SUBQ 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. Advise parents to report signs and symptoms of pancreatitis (persistent severe abdominal pain) and hypersensitivity reactions (rash, facial swelling, difficulty breathing) immediately to health care professional.
Rep: Advise patients of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
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.

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Indications ⬇