🔴 Red Flag (Important) Information
Administered as an IM injection only (gluteal muscle, both sides) — never IV.
Hepatic impairment: Avoid in severe liver disease; dose caution in mild–moderate impairment.
Monitor for thromboembolism and liver toxicity — increased risk with advanced disease or comorbidities.
Contains benzyl alcohol and ethanol — use caution in patients with hepatic disease, epilepsy, or alcoholism.
Avoid anticoagulants where possible — increased bleeding risk.
Not for premenopausal women, pregnancy, or breastfeeding.
🔹 1. Basic Information
Generic name: Fulvestrant
Brand name: Fulvestrant Mylan
Drug class: Estrogen receptor antagonist (Selective Estrogen Receptor Degrader, SERD)
Formulation: Solution for intramuscular injection
Strength: 250 mg/5 mL (pre-filled syringe)
Mechanism of Action:
Binds competitively to estrogen receptors → blocks estrogen activity → accelerates receptor degradation → inhibits estrogen-driven tumour growth.
🔹 2. Indications
Breast Cancer
Advanced or metastatic hormone receptor–positive breast cancer in postmenopausal women.
Often used after disease progression on anti-estrogen therapy (e.g. tamoxifen or aromatase inhibitors).
May be used as monotherapy or in combination with CDK4/6 inhibitors (e.g. palbociclib, abemaciclib).
🔹 3. Dosing & Administration
Dose: 500 mg IM (2 × 250 mg injections, one in each buttock).
Schedule:
Initial dose: Day 1.
Second dose: Day 15.
Maintenance: Every 4 weeks thereafter.
Route: Deep intramuscular injection (gluteal region).
Administration time: 1–2 minutes per injection.
Do not administer intravenously.
Supervision: Must be given by trained healthcare professional.
🔹 4. Dose Modifications
Hepatic impairment:
Mild–moderate: Use with caution.
Severe: Contraindicated.
Renal impairment: No adjustment required.
Overdose: Supportive management; no specific antidote.
🔹 5. Co-medications
Use cautiously with anticoagulants (e.g. warfarin, heparin) — ↑ bleeding risk.
Avoid estrogen-containing therapies.
May interfere with estradiol immunoassays → falsely elevated estradiol levels.
🔹 6. Contraindications
Hypersensitivity to fulvestrant or formulation excipients.
Severe hepatic impairment.
Pregnancy and breastfeeding.
Paediatric use (<18 years).
🔹 7. Monitoring Requirements
Baseline and periodic:
Liver function tests (ALT, AST, bilirubin).
Clinical assessment for thromboembolism.
Injection site reactions (pain, inflammation).
Signs of hypersensitivity or angioedema.
Bone health (osteoporosis risk).
In combination therapy: Monitor CBC and ECG as appropriate.
🔹 8. Side Effects & Management
| Frequency | Adverse Effect | Management |
|---|---|---|
| Very common (>10%) | Hot flushes, nausea, fatigue, headache, arthralgia, injection site pain | Symptomatic treatment |
| Common (1–10%) | Elevated LFTs, diarrhoea, anorexia, rash, back pain, vaginal bleeding, venous thromboembolism | Monitor LFTs, manage VTE appropriately |
| Uncommon (<1%) | Hypersensitivity, peripheral neuropathy, sciatica, muscle pain | Supportive care |
| Rare / Serious | Anaphylaxis, hepatitis, liver failure, thrombocytopenia | Discontinue; urgent medical attention |
🔹 9. Use in Special Populations
Hepatic impairment: Contraindicated in severe; caution in mild–moderate.
Renal impairment: No dose adjustment.
Elderly: No adjustment required.
Pregnancy/Lactation: Contraindicated.
Paediatrics: Not indicated.
🔹 10. Duration of Use / When to Stop the Drug
Continue until:
Disease progression, or
Unacceptable toxicity.
Stop if:
Severe hepatic toxicity.
Life-threatening hypersensitivity reaction.
Recurrent venous thromboembolism or anaphylaxis.
| Trade Name | Faslodex |
|---|---|
| Drug Class | Estrogen Receptor Antagonists |
| Cost | |
| Company | |
|---|---|
| Drug Rep | Admin |
| Indications | Breast Cancer |
| Dosage |