somatropin (recombinant)

BEERS REMS

Growth failure in children due to inadequate secretion of growth hormone.
Growth hormone deficiency in adults as a result of pituitary disease, hypothalamic disease, surgery, radiation, or trauma.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity to growth hormone or benzyl alcohol 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: Neonates (diluent contains benzyl alcohol and may cause fatal gasping syndrome);
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

Derm: exacerbation of pre-existing psoriasis

Endo: hyperglycemia, hypothyroidism, insulin resistance

Local: pain at injection site, local lipoatrophy or lipodystrophy

MS: arthralgia,, musculoskeletal pain,, swelling, stiffness

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 ⬆ ⬇

Powder for injection: 5 mg/vial; 8.8 mg/vial

Route/Dosage ⬆ ⬇

SC (Adults ): initially 0.005 mg/kg/day; may ↑ to 0.01 mg/kg/day after 4 wk.
SC (Children ): 0.06 mg (0.18 unit/kg) 3 times weekly.

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.
Increased bone density in adult growth hormone–deficient patients.

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: SUBQ: 3.8 hr.

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 report signs and symptoms of hypersensitivity reactions (rash, facial swelling, difficulty breathing) immediately to health care professional.
Rep: Advise females 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, evaluate lab work, and determine bone age by x-ray exam.

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Indications ⬇