Somavert

— THERAPEUTIC CATEGORIES —
  • Pituitary disorders

Somavert Generic Name & Formulations

General Description

Pegvisomant 10mg, 15mg, 20mg, 25mg, 30mg; per vial; lyophilized pwd for SC inj after reconstitution; contains mannitol.

Pharmacological Class

Growth hormone (GH) receptor antagonist.

How Supplied

Single-dose vial—1 (w. diluent)

Manufacturer

Generic Availability

NO

Mechanism of Action

Pegvisomant selectively binds to growth hormone (GH) receptors on cell surfaces and blocks endogenous GH, thus interfering with GH signal transduction and results in decreased serum concentrations of IGF-1 and other GH-responsive proteins (free IGF-I, IGFBP-3, and IGF-I ALS).

Somavert Indications

Indications

Treatment of acromegaly when response to surgery and/or radiation therapy and/or other medical therapies is inadequate or inappropriate.

Somavert Dosage and Administration

Adult

Give by SC inj into upper arm, upper thigh, buttocks, or abdomen; rotate inj site. Loading dose: 40mg once (under physician supervision). Maintenance therapy: 10mg daily; may adjust dose in increments/decrements of 5mg every 4–6 weeks based on IGF-I levels. Usual range: 10–30mg daily; max 30mg/day.

Children

Not established.

Administration

Administer SC into the thigh, buttocks, upper arm, or abdomen within 6 hours of reconstitution. Rotate inj sites. Loading dose must be given under physician supervision. Avoid doubling up if inj is missed.

Nursing Considerations

Administer SC into the thigh, buttocks, upper arm, or abdomen within 6 hours of reconstitution. Rotate inj sites. Loading dose must be given under physician supervision. Avoid doubling up if inj is missed.

Somavert Contraindications

Not Applicable

Somavert Boxed Warnings

Not Applicable

Somavert Warnings/Precautions

Warnings/Precautions

Monitor tumor growth, IGF-I levels, and for the development of GH deficiency. Obtain baseline ALT, AST, TBIL, ALP; if normal, monitor liver function monthly for first 6 months, then quarterly for next 6 months, then biannually for the next year; if elevated but ≤3×ULN, monitor monthly for ≥1yr, then biannually for the next year; if >3×ULN, do not treat until cause of liver dysfunction determined. Liver dysfunction during therapy: if ≥3×ULN but <5×ULN, monitor liver function weekly; if ≥5×ULN, or transaminase elevations ≥3×ULN associated with increase in TBIL, discontinue immediately, consider reinitiation if liver function normalizes with frequent monitoring; if liver injury occurs, discontinue therapy. Diabetes (monitor and adjust doses). Monitor closely when re-initiating therapy after systemic hypersensitivity reactions. Elderly. Pregnancy. Nursing mothers.

Somavert Pharmacokinetics

Distribution

Mean apparent volume of distribution: 7 L.

Elimination

Half-life: 60–138 hours.

Somavert Interactions

Interactions

May need to reduce dose of insulin, oral hypoglycemics. Antagonized by opioids (higher pegvisomant doses may be needed). May cause falsely elevated GH assays.

Somavert Adverse Reactions

Adverse Reactions

Infection, pain, diarrhea, nausea, elevated LFTs, flu syndrome, inj site reaction; lipohypertrophy, systemic hypersensitivity (eg, anaphylaxis, laryngospasm, angioedema, skin reactions).

Somavert Clinical Trials

See Literature

Somavert Note

Not Applicable

Somavert Patient Counseling

See Literature