🧾 Description:
Trastuzumab is a monoclonal antibody used primarily in the treatment of HER2-positive cancers, especially:
- Breast cancer
- Gastric (stomach) cancer
It targets the HER2/neu receptor, which is overexpressed in some cancer cells, helping to inhibit their growth.
⚙️ Mechanism of Action:
Trastuzumab binds to the extracellular domain of the HER2 receptor (human epidermal growth factor receptor 2), inhibiting:
- Cell proliferation
- Survival signals
- DNA repair of cancer cells
It also mediates antibody-dependent cellular cytotoxicity (ADCC).
💊 Dosage & Administration:
- Form: Lyophilized powder for injection (to be reconstituted)
- Strength: 440 mg vial + 50 mL of bacteriostatic water for injection (BWFI) with benzyl alcohol
- Route: Intravenous infusion (not IV push or bolus)
Typical Dosing:
- Loading dose: 8 mg/kg IV over 90 minutes
- Maintenance: 6 mg/kg IV every 3 weeks over 30–90 minutes
Note: Subcutaneous (SC) formulations also exist with fixed doses (e.g., 600 mg).
🤒 Common Side Effects:
- Fever, chills, nausea
- Diarrhea
- Fatigue
- Infusion-related reactions
- Headache
- Rash
- Cardiotoxicity (especially ↓ LVEF)
🚨 Precautions:
- Cardiac monitoring (especially LVEF) is required
- Caution in pregnancy (Category D – known fetal risk)
- Infusion reactions are common — premedication may be needed
- Not interchangeable with biosimilars unless specifically approved
🔄 Interactions:
- Risk of cardiotoxicity increases when combined with anthracyclines (e.g., doxorubicin)
- May interact with other HER2-targeted therapies (e.g., pertuzumab)
📦 Storage:
- Store refrigerated at 2°C to 8°C (36°F to 46°F)
- Do not freeze
- After reconstitution:
- Stable for 28 days at 2–8°C
- Do not shake
🧍♂️ Patient Advice:
🧾 Description:
Trastuzumab is a monoclonal antibody used primarily in the treatment of HER2-positive cancers, especially:
- Breast cancer
- Gastric (stomach) cancer
It targets the HER2/neu receptor, which is overexpressed in some cancer cells, helping to inhibit their growth.
🚨 Precautions:
- Cardiac monitoring (especially LVEF) is required
- Caution in pregnancy (Category D – known fetal risk)
- Infusion reactions are common — premedication may be needed
- Not interchangeable with biosimilars unless specifically approved
📦 Storage:
- Store refrigerated at 2°C to 8°C (36°F to 46°F)
- Do not freeze
- After reconstitution:
- Stable for 28 days at 2–8°C
- Do not shake
🧍♂️ Patient Advice:
- Report symptoms like shortness of breath, chest pain, dizziness, or swelling
- Attend all cardiac checkups
- Women of childbearing potential should use effective contraception during and at least 7 months after therapy
- Inform your healthcare provider if pregnant or breastfeeding