Home Drug Guide Pegvisomant

Drug Guide

Generic Name

Pegvisomant

Brand Names Somavert

Classification

Therapeutic: Antineoplastic, Growth Hormone Receptor Antagonist

Pharmacological: Biologic, Recombinant DNA Protein

FDA Approved Indications

  • Treatment of acromegaly in patients who have failed or are intolerant to other therapies

Mechanism of Action

Pegvisomant is a genetically engineered, pegylated growth hormone (GH) receptor antagonist that blocks the action of GH, thereby decreasing insulin-like growth factor 1 (IGF-1) levels.

Dosage and Administration

Adult: Initial dose: 10 mg subcutaneously once daily. Dose adjustments as needed based on IGF-1 levels, up to 30 mg daily.

Pediatric: Not typically used in pediatric patients.

Geriatric: No specific dosage adjustments, but monitor closely due to potential comorbidities.

Renal Impairment: No specific adjustment; use caution and monitor hepatic function.

Hepatic Impairment: Use with caution; hepatic function should be monitored throughout therapy.

Pharmacokinetics

Absorption: Peak plasma concentrations occur approximately 2-4 hours after subcutaneous injection.

Distribution: Widely distributed with a volume of distribution of approximately 7–10 liters.

Metabolism: Metabolized via proteolytic degradation similar to endogenous proteins.

Excretion: Eliminated primarily through proteolytic degradation; not primarily excreted renally.

Half Life: Approximately 3-6 days depending on dose and patient.

Contraindications

  • Hypersensitivity to pegvisomant or excipients.

Precautions

  • Hepatic impairment: risk of increased liver enzymes and potential hepatotoxicity. Regular liver function tests are recommended.
  • Monitor for signs of hypersensitivity reactions.
  • Use with caution in patients with impaired hepatic function.

Adverse Reactions - Common

  • Liver enzyme elevations (ALT, AST) (Common)
  • Injection site reactions (Common)
  • Headache, nausea (Common)

Adverse Reactions - Serious

  • Hepatotoxicity (Rare, potentially serious)
  • Anaphylaxis, hypersensitivity reactions (Rare)

Drug-Drug Interactions

  • Other hepatotoxic drugs

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor liver function tests before treatment and periodically during therapy. Assess for signs of hypersensitivity.

Diagnoses:

  • Risk for hepatic injury
  • Altered medication efficacy

Implementation: Administer subcutaneously once daily at the same time each day. Educate patient on injection technique.

Evaluation: Regular assessment of IGF-1 levels, liver function tests, and clinical response.

Patient/Family Teaching

  • Instruct on proper injection technique.
  • Report any symptoms of allergic reactions, jaundice, or severe headache.
  • Inform that therapy requires regular blood tests.
  • Advise not to stop medication without consulting healthcare provider.

Special Considerations

Black Box Warnings:

  • Hepatotoxicity, including liver failure, has been reported. Liver function must be monitored regularly.

Genetic Factors: Not specifically indicated.

Lab Test Interference: May affect liver function tests; interpret with caution.

Overdose Management

Signs/Symptoms: Liver enzyme elevations, hypersensitivity reactions.

Treatment: Discontinue pegvisomant and monitor liver function. Supportive care as needed.

Storage and Handling

Storage: Store refrigerated (36°F to 46°F or 2°C to 8°C). Do not freeze.

Stability: Stable for up to 30 days at room temperature, but refrigeration is preferred.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.