Short answer: Evista (raloxifene) is an estrogen agonist/antagonist taken as 60 mg once a day, approved for postmenopausal osteoporosis and to lower invasive breast cancer risk in some women.1 Fosamax (alendronate) is a bisphosphonate taken 70 mg once a week with a strict empty-stomach routine.2 Evista has a boxed warning on blood clots and stroke death. Neither label reports a trial against the other.
| Evista (raloxifene) | Fosamax (alendronate) | |
|---|---|---|
| Drug type | Estrogen agonist/antagonist1 | Bisphosphonate2 |
| Approved for | Treat and prevent postmenopausal osteoporosis; lower invasive breast cancer risk in postmenopausal women with osteoporosis or at high risk1 | Postmenopausal osteoporosis (treat and prevent); men; steroid-induced osteoporosis; Paget's disease2 |
| Dose | 60 mg once a day, any time, with or without food1 | 70 mg once a week (or 10 mg daily), on waking, plain water, 30 minutes before food, upright2 |
| Side effects in label trials | Hot flashes 9.7% vs 6.4%; leg cramps 7.0% vs 3.7%; joint pain 15.5% vs 14.0%1 | Abdominal pain 6.6% vs 4.8%; musculoskeletal pain 4.1% vs 2.5%2 |
| Boxed warning | Blood clots, and death from stroke in women with heart disease or at higher risk1 | None2 |
| Missed dose | Take when remembered unless the next dose is near; never two at once1 | Take the next morning; then back to the usual day2 |
They are different kinds of drug. Evista acts on estrogen receptors, which is why its label also covers lowering invasive breast cancer risk and why it carries a boxed warning on blood clots in the legs and lungs and on stroke death in women with heart disease. It is stopped at least 72 hours before long immobilization.1 Fosamax binds to bone; its key warnings are esophagus irritation, low calcium, jaw bone death and unusual thigh fractures.2
Evista is approved only for postmenopausal women; Fosamax is also approved for men, steroid-induced osteoporosis and Paget's disease.12 These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
Your prescriber weighs these against your own history. More detail: Evista side effects, Fosamax side effects, the Evista and Fosamax dosing schedules, and the Evista and Fosamax missed-dose pages.