Generic Name

Evista

Mechanism

• Selective ER agonism/antagonism:
• Acts as an estrogen agonist in bone, stimulating osteoblast-mediated bone formation and inhibiting osteoclast activity → ↑ bone mineral density (BMD).
• Functions as an estrogen antagonist in breast and uterine tissue → ↓ risk of estrogen‑dependent malignancies; minimal stimulation of the endometrium.
• Downstream effects:
• Decreases serum osteocalcin, reduces bone turnover markers.
• Lowers serum estradiol‑induced proliferation in mammary epithelium.

Pharmacokinetics

• Absorption: Oral; ~45 % bioavailability; peak plasma concentration (Tmax) ≈ 2 h.
• Distribution: Highly protein‑bound (95 % to serum albumin).
• Metabolism: Primarily hepatic via CYP3A4; metabolites are inactive.
• Elimination: Renal excretion of metabolites; terminal half‑life ≈ 25 h.
• Drug interactions:
• Co‑administration with potent CYP3A4 inhibitors (Ketoconazole, Itraconazole) ↑ plasma levels.
• No significant interaction with warfarin or H₂‑blockers.

Indications

• Osteoporosis prevention in postmenopausal women with low BMD (T‑score ≤ –1.0).
• Treatment of established postmenopausal osteoporosis (T‑score ≤ –2.5).
• Breast cancer risk reduction in postmenopausal women with elevated 10‑year risk (e.g., Gail model > 3 % or Ashes‑BRCAPRO).
• Research: Used in studies of bone loss and arterial calcification.

Contraindications

• Contraindications:
• Known or suspected estrogen‑dependent breast cancer or endometrial cancer.
• Active venous thromboembolism (VTE) or severe hypercoagulable states.
• Untreated severe hepatic disease.
• Warnings:
• Thromboembolic events: Deep vein thrombosis, pulmonary embolism; rare but serious.
• Hot flashes: May be precipitated; not a contraindication but requires monitoring.
• Cataract progression: Occasionally noted; baseline ophthalmologic evaluation for high‑risk patients.

Dosing

• Administration with food: Improves absorption; however, consistent timing is key.
• Missed dose: Take as soon as remembered; skip if near next dose.

Adverse Effects

• Common (≥ 2 % incidence)
• Hot flashes (28 %).
• Leg cramps (9 %).
• Joint pain (9 %).
• Abdominal pain (7 %).
• Myalgia (5 %).
• Insomnia (5 %).
• Serious (≥ 1 % incidence)
• Venous thromboembolism (~1 %); circumstances: immobility, recent surgery, smoking.
• Severe hypersensitivity reactions (rare).
• Cerebral thromboembolism (rare).

Monitoring

• Baseline:
• Bone mineral density (DXA) at femoral neck and lumbar spine.
• Complete blood count (CBC) & basic metabolic panel (BMP).
• Coagulation profile if indicated (e.g., prolonged use in high‑risk patients).
• Periodic:
• DXA every 1–2 years to assess treatment response.
• Monitor for signs/symptoms of VTE (leg swelling, dyspnea, chest pain).
• Lifestyle: Encourage calcium (≥ 1000 mg/day) and vitamin D (600 IU/day) supplementation; maintain weight‑bearing exercise.

Clinical Pearls

• Simultaneous calcium/vitamin D is essential; raloxifene alone will not offset calcium deficiency.
• Contraindication check: A simple triple‑negative “VTE screen” (history of DVT/PE, recent surgery, smoking) can help prevent serious thrombotic events.
• Adherence strategy: Set a nightly routine—taking Evista with a glass of water and a light snack can improve compliance.
• Risk‑benefit ratio: In postmenopausal women with low BMD (T‑score ≤ –1.0) but increased breast cancer risk, raloxifene is often preferable to estrogen/combined hormone therapy because of its net estrogenic benefits to bone and anti‑estrogenic protection to breast/uterus.
• Drug interactions: A shoulder‑check for CYP3A4 inhibitors before initiating therapy is advised to avoid elevated drug exposures.
• Switching: If patient tolerates raloxifene poorly, estrogen therapy alone may produce more hot flashes but preserves bone density; switching should occur only after a multidisciplinary discussion.

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• *For further detailed guidance, refer to the latest FDA prescribing information and clinical practice guidelines on osteoporosis and breast cancer chemoprophylaxis.*