Home Drug Guide Ado-trastuzumab Emtansine

Drug Guide

Generic Name

Ado-trastuzumab Emtansine

Brand Names Kadcyla

Classification

Therapeutic: Antineoplastic agent (antibody-drug conjugate)

Pharmacological: HER2-targeted antibody-drug conjugate

FDA Approved Indications

  • Treatment of HER2-positive breast cancer that has either received prior trastuzumab-based therapy and is locally advanced or metastatic
  • Adjuvant therapy of HER2-positive early breast cancer (approved in some regions)

Mechanism of Action

Ado-trastuzumab Emtansine combines trastuzumab, an anti-HER2 monoclonal antibody, with emtansine (DM1), a cytotoxic agent. It binds to HER2-expressing cancer cells, is internalized, and releases DM1, which inhibits microtubule assembly, leading to cell cycle arrest and apoptosis.

Dosage and Administration

Adult: Approximate dose: 3.6 mg/kg IV every 3 weeks, administered as an infusion over 30-90 minutes.

Pediatric: Not indicated.

Geriatric: No specific dosage adjustment; use with caution and monitor response.

Renal Impairment: Limited data, use caution; no specific recommendations.

Hepatic Impairment: Use with caution; adjust dose as needed, especially in severe impairment.

Pharmacokinetics

Absorption: administered intravenously; bioavailability is complete.

Distribution: Widely distributed; volume of distribution approximately 4.5 L.

Metabolism: Metabolized by proteolytic degradation into amino acids; DM1 is released intracellularly.

Excretion: Primarily via feces; minimal renal excretion.

Half Life: Approximately 4 days.

Contraindications

  • Hypersensitivity to ado-trastuzumab emtansine or its components

Precautions

  • Monitor for cardiotoxicity, hepatotoxicity, and infusion reactions.
  • Use in pregnancy and lactation only if clearly needed; potential risk to fetus and infant.

Adverse Reactions - Common

  • Nausea (Common)
  • Fatigue (Common)
  • Musculoskeletal pain (Common)
  • Neutropenia (Common)

Adverse Reactions - Serious

  • Hepatotoxicity (ALT/AST elevations, hepatic failure) (Serious)
  • Severe and fatal infusion-related reactions (Serious)
  • Left ventricular systolic dysfunction (cardiotoxicity) (Serious)
  • Peripheral neuropathy (Serious)

Drug-Drug Interactions

  • Other cardiotoxic agents, hepatotoxic drugs, or drugs affecting blood counts.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor cardiac function (LVEF) prior to and during treatment, complete blood counts, and liver function tests.

Diagnoses:

  • Risk for cardiotoxicity
  • Risk for neutropenia or infection
  • Risk for hepatotoxicity

Implementation: Administer IV infusion as scheduled, monitor for infusion reactions, monitor blood counts and liver function, educate patient on signs of toxicity.

Evaluation: Assess efficacy (tumor response), monitor adverse effects, adjust treatment as necessary.

Patient/Family Teaching

  • Report signs of allergic reactions, new or worsening symptoms, chest pain, or signs of infection.
  • Keep appointments for cardiac and blood tests.
  • Inform about possible side effects and when to seek medical attention.

Special Considerations

Black Box Warnings:

  • Hepatotoxicity, embryofetal toxicity, cardiomyopathy, and infusion reactions.
  • Monitor LVEF regularly.
  • Pregnancy risk: use contraception during and for at least 7 months after treatment.

Genetic Factors: No specific genetic considerations.

Lab Test Interference: May alter liver function tests and blood counts.

Overdose Management

Signs/Symptoms: Severe myelosuppression, anaphylaxis, cardiomyopathy.

Treatment: Supportive care, stop drug, monitor vital signs, treat symptoms accordingly.

Storage and Handling

Storage: Store in a refrigerator at 2-8°C. Do not freeze.

Stability: Stable for 28 days at 2-8°C after reconstitution.

🛡️ 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.