somatropin (recombinant)

BEERS REMS

Growth failure in children due to Prader-Willi syndrome.
Growth failure in children due to deficiency of growth hormone.
Growth failure in children born small for gestational age who fail to manifest catch-up growth by age 2.
Short stature associated with Turner syndrome.
Idiopathic short stature in children.
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 m-cresol 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: Girls with Turner syndrome (↑ risk for pancreatitis); 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 ⬆ ⬇

Powder for injection (intramix cartridges with preservative): 5 mg/cartridge (green); 12 mg/cartridge (purple)
Powder for injection (Miniquick system without preservative): 0.2 mg/cartridge; 0.4 mg/cartridge; 0.6 mg/cartridge; 0.8 mg/cartridge; 1 mg/cartridge; 1.2 mg/cartridge; 1.4 mg/cartridge; 1.6 mg/cartridge; 1.8 mg/cartridge; 2 mg/cartridge
Powder for injection (GoQuick prefilled pen with preservative): 5 mg/pen; 5.3 mg/pen; 12 mg/pen

Route/Dosage ⬆ ⬇

SC (Children ): Growth hormone inadequacy: 0.16–0.24 mg/kg/wk divided in 6–7 daily doses. Prader-Willi syndrome: 0.24 mg/kg/wk divided into 6–7 daily doses.Children SGA at birth: 0.48 mg/kg/wk divided into 6–7 daily doses.Turner syndrome: 0.33 mg/kg/wk divided into 6–7 daily doses. Idiopathic short stature: 0.47 mg/kg/wk divided into 6–7 daily doses.
SC (Adults ): 0.04 mg/kg/wk initially divided in 6–7 daily doses 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 (max dose = 0.08 mg/kg/wk).

US Brand Names ⬆ ⬇

Genotropin, Genotropin MiniQuick

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 (80%).

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 ⬆ ⬇

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. Parents should also be advised to report persistent severe abdominal pain (may be a symptom of pancreatitis) and 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 ⬇