Evista: Uses, Dosage & Side Effects

What Is Evista and What Is It Used For?

Evista contains the active substance raloxifene hydrochloride, a second-generation selective estrogen receptor modulator (SERM). SERMs are a class of compounds that interact with intracellular estrogen receptors in target organs as estrogen agonists or antagonists, depending on the specific tissue. Raloxifene was specifically designed to provide the skeletal benefits of estrogen in postmenopausal women while avoiding the potentially harmful estrogenic effects on the breast and uterus that are associated with traditional hormone replacement therapy (HRT).

The loss of estrogen production after menopause is the primary driver of postmenopausal osteoporosis, a condition characterized by progressive loss of bone mineral density (BMD), deterioration of bone microarchitecture, and increased susceptibility to fractures. During the first 5 to 10 years after menopause, women can lose up to 20% of their bone density, with the vertebral bodies of the spine and the proximal femur (hip) being particularly vulnerable. Osteoporosis is often called a “silent disease” because bone loss occurs without symptoms until a fracture occurs. Vertebral compression fractures, hip fractures, and wrist fractures are the most common osteoporotic fractures, and they carry significant morbidity, mortality, and healthcare costs worldwide.

Raloxifene exerts its tissue-selective effects through a unique molecular mechanism. When raloxifene binds to the estrogen receptor (ER), it induces a conformational change in the receptor that is different from the conformation induced by estradiol (the body's primary estrogen). This altered conformation affects which coactivator and corepressor proteins are recruited to the receptor-DNA complex, ultimately determining whether gene transcription is activated or suppressed in a given tissue. In bone tissue, raloxifene acts as an estrogen agonist, activating estrogen-responsive genes that promote osteoblast (bone-forming cell) activity and inhibit osteoclast (bone-resorbing cell) function. This results in decreased bone turnover, increased bone mineral density, and preservation of bone structural integrity. In breast tissue and the uterine endometrium, raloxifene acts as an estrogen antagonist, blocking the proliferative effects of estrogen on these tissues.

The clinical efficacy of Evista in osteoporosis has been established through several large-scale, randomized, double-blind, placebo-controlled clinical trials. The most important of these is the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, a landmark study that enrolled 7,705 postmenopausal women with osteoporosis across 180 clinical centers in 25 countries. The MORE trial demonstrated that raloxifene 60 mg daily significantly reduced the risk of new vertebral fractures by 30% in women with prevalent vertebral fractures and by 50% in women without prevalent fractures, compared with placebo, over a median treatment period of 36 months. These fracture risk reductions were accompanied by significant increases in BMD at the lumbar spine (2.6% increase) and femoral neck (2.1% increase) compared with placebo.

In addition to its skeletal benefits, the MORE trial revealed an unexpected but clinically important finding: raloxifene significantly reduced the incidence of invasive breast cancer in postmenopausal women. Women treated with raloxifene 60 mg daily had a 72% reduction in the risk of invasive breast cancer compared with the placebo group over 4 years of follow-up. This breast cancer risk reduction was subsequently confirmed and extended in the Raloxifene Use for The Heart (RUTH) trial, a large cardiovascular outcomes study involving 10,101 postmenopausal women at increased risk for major coronary events. The RUTH trial demonstrated a 44% reduction in invasive breast cancer incidence with raloxifene over a median follow-up of 5.6 years, while showing no increase in coronary heart disease events.

Evista was first approved by the U.S. Food and Drug Administration (FDA) in December 1997 for the prevention of osteoporosis in postmenopausal women, and its indication was subsequently expanded to include treatment of osteoporosis. The European Medicines Agency (EMA) granted marketing authorization for Evista in the European Union in 1998. In 2007, the FDA additionally approved raloxifene for the reduction of risk of invasive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk for invasive breast cancer. Evista is currently approved and marketed in more than 70 countries worldwide.

What Should You Know Before Taking Evista?

Contraindications

Evista must not be used in several clearly defined clinical situations. The most critical contraindication is active or past history of venous thromboembolic events (VTE), including deep vein thrombosis (DVT), pulmonary embolism (PE), and retinal vein thrombosis. Raloxifene increases the risk of VTE by approximately 1.5 to 3 times compared with placebo, and this risk is highest during the first 4 months of treatment and during periods of immobilization. In the MORE trial, the incidence of DVT was 1.0% in the raloxifene 60 mg group compared with 0.5% in the placebo group over 3 years. In the RUTH trial, VTE events occurred in 3.1% of raloxifene-treated women compared with 2.0% in the placebo group over 5.6 years.

Additional contraindications include: hypersensitivity to raloxifene or any of the excipients in the formulation; pregnancy or possibility of pregnancy (raloxifene is Category X—it may cause fetal harm); breastfeeding; unexplained uterine bleeding that has not been evaluated by a healthcare provider; and severe hepatic impairment, including cholestasis. Raloxifene should also not be used in premenopausal women, as its safety and efficacy have only been established in postmenopausal women.

Warnings and Precautions

Before starting Evista, discuss the following important considerations with your healthcare provider:

• Venous thromboembolism: As described above, raloxifene increases VTE risk. Women with additional risk factors for VTE—such as obesity, varicose veins, history of superficial thrombophlebitis, active smoking, or use of systemic estrogens—should be carefully evaluated before starting treatment. The risks and benefits should be weighed in each individual case.
• Stroke risk: In the RUTH trial, raloxifene was associated with an increased risk of fatal stroke compared with placebo (59 versus 39 events; hazard ratio 1.49). This risk increase was primarily observed in women with established cardiovascular risk factors. Women at increased risk for stroke (e.g., those with a history of stroke or transient ischemic attack, atrial fibrillation, uncontrolled hypertension, or heavy smoking) should discuss the potential stroke risk with their doctor before starting Evista.
• Hepatic impairment: Raloxifene is extensively metabolized in the liver. It has not been adequately studied in patients with moderate hepatic impairment and is contraindicated in severe hepatic impairment. Serum raloxifene concentrations may be elevated in patients with impaired liver function. Liver function should be assessed before starting treatment.
• Renal impairment: Raloxifene should be used with caution in patients with moderate to severe renal impairment. In pharmacokinetic studies, single doses of raloxifene resulted in a 56% higher area under the plasma concentration-time curve (AUC) in patients with mild renal impairment compared with healthy volunteers. The clinical significance of this finding in long-term use is not fully established.
• Triglycerides: Raloxifene has been associated with modest increases in serum triglyceride levels. In clinical trials, serum triglycerides increased by approximately 6–11% compared with placebo. Women with pre-existing hypertriglyceridemia (especially levels greater than 500 mg/dL) should be monitored closely, as substantial triglyceride elevations may increase the risk of pancreatitis.

Pregnancy and Breastfeeding

Evista is strictly contraindicated during pregnancy and in women who may become pregnant. Raloxifene is classified as Pregnancy Category X, meaning that animal studies have shown evidence of fetal toxicity and the risk to the fetus clearly outweighs any potential benefit. In animal reproductive studies, raloxifene caused delays in fetal development, decreased neonatal survival, altered physical development, changes in reproductive tract development, and reduced fertility in offspring. Although Evista is indicated only for postmenopausal women (who cannot become pregnant naturally), any woman of childbearing potential should have a negative pregnancy test before starting treatment, and effective contraception should be used if there is any possibility of pregnancy.

It is not known whether raloxifene is excreted in human breast milk. Given the potential for serious adverse effects on the nursing infant, Evista must not be used during breastfeeding. This contraindication is primarily relevant in the rare clinical scenario where raloxifene might be considered for off-label use in premenopausal women for breast cancer chemoprevention.

Hot Flashes and Menopausal Symptoms

Unlike traditional hormone replacement therapy, Evista does not relieve and may actually worsen vasomotor symptoms (hot flashes and night sweats). In the MORE trial, the incidence of hot flashes was approximately 24.6% in the raloxifene 60 mg group compared with 18.3% in the placebo group. This is an important consideration for women who are experiencing significant menopausal symptoms, as raloxifene would not provide symptomatic relief and might increase their discomfort. Women for whom hot flashes are a significant quality-of-life concern should discuss alternative treatment options with their healthcare provider.

Driving and Operating Machinery

Evista is not expected to affect the ability to drive or operate machinery. No specific studies on driving ability have been performed with raloxifene. Based on its pharmacological profile and the side effects observed in clinical trials, raloxifene does not cause sedation, dizziness, or impairment of cognitive function that would interfere with driving or operating machinery. However, individual responses to medication can vary, and patients should exercise appropriate caution.

How Does Evista Interact with Other Drugs?

Raloxifene is extensively metabolized through glucuronidation in the gut wall and liver, primarily by uridine diphosphate-glucuronosyltransferase (UGT) enzymes. Unlike many oral medications, raloxifene does not undergo significant cytochrome P450 (CYP) enzyme-mediated metabolism. This means that classic CYP-mediated drug interactions are generally not a concern with raloxifene. However, the glucuronidation pathway and the drug's binding to plasma proteins create specific interaction risks that are clinically relevant.

Raloxifene is more than 95% bound to plasma proteins, including albumin and alpha-1 acid glycoprotein. It does not, however, appear to interact with the binding of other highly protein-bound drugs such as warfarin, phenytoin, or tamoxifen in clinical studies, although interactions at the pharmacodynamic level may occur with some of these agents.

Major Interactions

The most clinically significant interaction is between raloxifene and cholestyramine (and by extension, other bile acid sequestrants such as colestipol and colesevelam). Cholestyramine reduces the absorption and enterohepatic cycling of raloxifene by approximately 60%, which substantially diminishes the drug's therapeutic effect. Raloxifene undergoes significant enterohepatic recirculation—after oral administration, it is absorbed, conjugated to glucuronides in the gut wall and liver, excreted in bile, hydrolyzed back to raloxifene by gut bacteria, and reabsorbed. Bile acid sequestrants interrupt this recycling process by binding to the glucuronide conjugates in the gut, preventing their reabsorption. If both medications are absolutely necessary, they should be separated by at least 4 to 6 hours, although avoidance of concomitant use is preferred.

The interaction between raloxifene and warfarin is also clinically important. In clinical studies, raloxifene has been shown to produce a modest (approximately 10%) decrease in prothrombin time when given concomitantly with warfarin. While this effect is relatively small, the narrow therapeutic index of warfarin means that even modest changes in anticoagulant activity can have clinically meaningful consequences. The international normalized ratio (INR) should be monitored closely when raloxifene therapy is initiated, changed, or discontinued in patients taking warfarin or other vitamin K antagonists.

Minor Interactions

Ampicillin reduces the peak plasma concentration of raloxifene by approximately 28%, likely by altering intestinal bacteria involved in the enterohepatic recycling of raloxifene glucuronides. However, the overall extent of absorption (as measured by AUC) is not significantly affected, and this interaction is not considered clinically significant. No dosage adjustment is required when raloxifene is taken with ampicillin or other antibiotics.

Raloxifene does not affect the pharmacokinetics of methylprednisolone given as a single intravenous dose. Additionally, population pharmacokinetic analyses from clinical trials have shown that commonly co-administered medications—including calcium supplements, acetaminophen (paracetamol), nonsteroidal anti-inflammatory drugs (NSAIDs), oral hypoglycemics, proton pump inhibitors, and H2-receptor antagonists—do not significantly affect raloxifene plasma concentrations.

What Is the Correct Dosage of Evista?

Adults (Postmenopausal Women)

The duration of treatment with Evista should be individualized based on the patient's fracture risk, response to therapy, and ongoing benefit-risk assessment. In clinical trials, the efficacy and safety of raloxifene have been demonstrated over treatment periods of up to 8 years (the original 4-year MORE trial plus a 4-year extension study, known as CORE). Current clinical guidelines generally recommend that osteoporosis treatment be continued for at least 3 to 5 years, with reassessment of the need for ongoing therapy at regular intervals. Unlike bisphosphonates, there is no concern about prolonged skeletal half-life with raloxifene, meaning that the drug does not accumulate in bone and its effects are reversible upon discontinuation.

Children and Adolescents

Evista is not indicated for use in children, adolescents, or premenopausal women. The safety and efficacy of raloxifene have not been established in pediatric populations. Osteoporosis treatment in children and adolescents (e.g., secondary to glucocorticoid use or genetic conditions such as osteogenesis imperfecta) requires different therapeutic approaches, and healthcare providers should consider age-appropriate alternatives such as bisphosphonates with appropriate pediatric dosing.

Elderly Patients

No dose adjustment is required for elderly postmenopausal women taking Evista. In clinical trials, the majority of participants were 65 years of age or older, and raloxifene demonstrated consistent efficacy in reducing vertebral fracture risk across all age subgroups studied (up to age 80). The pharmacokinetics of raloxifene are not significantly altered by age alone. However, elderly patients may have additional risk factors for venous thromboembolism (such as decreased mobility, concurrent medications, and comorbid conditions), and the benefit-risk assessment should be carefully considered in this population.

Missed Dose

If you miss a dose of Evista, take it as soon as you remember on the same day. If it is already the next day, skip the missed dose and take the next dose at your usual time. Do not take a double dose to make up for a missed dose. The long elimination half-life of raloxifene (approximately 27.7 hours) means that a single missed dose is unlikely to significantly affect the overall therapeutic effect. However, consistent daily adherence is important for optimal long-term bone protection. Setting a daily alarm or associating the tablet with a regular daily activity (such as breakfast or brushing teeth) can help improve adherence.

Overdose

There is limited clinical experience with raloxifene overdose. In clinical trials, doses up to 600 mg/day (10 times the recommended dose) were administered for 8 weeks without dose-limiting adverse effects. In a post-marketing surveillance study, an adult ingested 1,500 mg of raloxifene and recovered without sequelae. There is no specific antidote for raloxifene overdose. Treatment should be supportive and symptomatic. Symptoms that might be expected based on the pharmacological profile include leg cramps, dizziness, hot flashes, nausea, and vomiting. In the event of a suspected overdose, contact your local poison control center or emergency department immediately.

What Are the Side Effects of Evista?

Like all medicines, Evista can cause side effects, although not everybody gets them. The safety profile of raloxifene has been extensively characterized through large clinical trials involving more than 25,000 postmenopausal women, with follow-up periods extending up to 8 years. The overall discontinuation rate due to adverse events in clinical trials was similar between the raloxifene and placebo groups, indicating that the medication is generally well tolerated. The side effects below are categorized by frequency according to the standard medical classification system.

The most clinically important adverse effect of Evista is the increased risk of venous thromboembolism (VTE). In the MORE trial, the incidence of VTE (DVT and PE combined) was approximately 1.0% in the raloxifene group compared with 0.3% in the placebo group over 40 months. In the RUTH trial, VTE occurred in 3.1% of raloxifene-treated women compared with 2.0% in the placebo group over 5.6 years. The absolute risk is relatively low, but women with additional VTE risk factors should be carefully assessed before starting treatment. Warning signs of VTE include sudden pain, swelling, or warmth in one leg (DVT), or sudden shortness of breath, chest pain, or coughing up blood (PE), and require immediate medical attention.

Hot flashes are the most common reason patients discontinue Evista. They tend to be most pronounced during the first 6 months of therapy and generally improve over time. In clinical trials, about 24.6% of raloxifene-treated women reported hot flashes compared with 18.3% in the placebo group. The mechanism is related to raloxifene's partial antagonist activity at estrogen receptors in the thermoregulatory center of the hypothalamus. Hot flashes are more common in women who experienced significant menopausal vasomotor symptoms before starting treatment.

Leg cramps are another frequently reported side effect, occurring in approximately 5.9% to 9.2% of raloxifene-treated women compared with 3.7% to 6.0% in placebo groups. The mechanism is not fully understood but may relate to raloxifene's effects on calcium homeostasis or vascular smooth muscle. Leg cramps are usually mild to moderate in severity and can often be managed with stretching exercises, adequate hydration, and ensuring sufficient magnesium and potassium intake.

Importantly, Evista has a favorable safety profile compared with traditional hormone replacement therapy regarding certain outcomes. Unlike combined estrogen-progestin HRT, raloxifene does not cause breast tenderness, uterine bleeding, or endometrial hyperplasia. It does not increase the risk of endometrial cancer. The MORE trial and its extension studies demonstrated a significant reduction in the incidence of invasive breast cancer with raloxifene treatment. Additionally, raloxifene has beneficial effects on several cardiovascular risk markers, including reductions in total cholesterol and LDL cholesterol, without significantly affecting HDL cholesterol or triglyceride levels (although modest triglyceride increases have been reported in some patients).

How Should You Store Evista?

Proper storage of Evista is important to ensure the medication remains effective and safe throughout its shelf life. The following storage guidelines should be followed:

• Temperature: Store at room temperature, not above 25°C (77°F). Do not freeze. Brief exposure to temperatures up to 30°C (86°F) during transportation is acceptable but should be minimized.
• Light protection: Keep the tablets in their original blister packaging until ready to use, as raloxifene may be sensitive to prolonged light exposure.
• Moisture: Store in a dry place. Do not store in the bathroom or other areas with high humidity, as moisture can degrade the film coating and the active ingredient.
• Children: Keep out of reach and sight of children. Store in a secure location to prevent accidental ingestion.
• Expiration date: Do not use Evista after the expiration date (EXP) printed on the blister pack and carton. The expiration date refers to the last day of that month.

Do not dispose of unused or expired medications in household waste or down the drain. Return unused or expired tablets to your pharmacist or local waste disposal facility for safe disposal. This helps protect the environment from pharmaceutical contamination. If you notice any change in the appearance of the tablets (such as discoloration, crumbling, or unusual odor), do not take them and consult your pharmacist.

What Does Evista Contain?

Active ingredient: Each film-coated tablet contains raloxifene hydrochloride 60 mg, which is equivalent to approximately 56 mg of raloxifene free base. Raloxifene hydrochloride has the molecular formula C₂₈H₂₇NO₄S·HCl and a molecular weight of 510.05 g/mol. It is a white to pale yellow solid that is slightly soluble in water.

Inactive ingredients (excipients): The tablet core contains povidone, polysorbate 80, lactose monohydrate, lactose anhydrous, crospovidone, magnesium stearate, and purified water (removed during manufacturing). The film coating consists of a pre-formulated coating material containing carnauba wax and other film-forming agents that give the tablet its characteristic smooth, white to off-white appearance.

Important note for patients with lactose intolerance: Evista tablets contain lactose (both monohydrate and anhydrous forms). Patients with rare hereditary problems of galactose intolerance, total lactase deficiency, or glucose-galactose malabsorption should not take this medicine. The amount of lactose per tablet is relatively small, but patients with severe lactose intolerance should discuss this with their healthcare provider.

Tablet description: Evista 60 mg tablets are white to off-white, oval-shaped, film-coated tablets. They are debossed with “LILLY” on one side and “4165” on the other. The tablets are packaged in PVC/aluminum blister packs, available in pack sizes of 14, 28, 84, or 336 tablets (not all pack sizes may be marketed in all countries).