Short answer: Ibandronate (the generic of Boniva) and Fosamax (alendronate) are bisphosphonate tablets for osteoporosis.12 Ibandronate is one 150 mg tablet a month with a 60-minute wait before food; Fosamax is 70 mg a week with a 30-minute wait. Ibandronate is approved for postmenopausal women only. Neither label reports a trial against the other.
| Ibandronate (Boniva generic) | Fosamax (alendronate) | |
|---|---|---|
| Approved for | Treat and prevent postmenopausal osteoporosis1 | Postmenopausal osteoporosis (treat and prevent); men; steroid-induced osteoporosis; Paget's disease2 |
| Schedule | 150 mg once a month, same date each month1 | 70 mg once a week (or 10 mg daily)2 |
| Wait before food or drink | At least 60 minutes; upright 60 minutes1 | At least 30 minutes; upright 30 minutes2 |
| Side effects in label trials | Abdominal pain 7.8%, high blood pressure 6.3%, indigestion and joint pain 5.6% each (2-year trial of 150 mg monthly)1 | Abdominal pain 6.6% vs 4.8% on placebo (3-year trials, drug-related)2 |
| Missed dose | Take the next morning if the next dose is more than 7 days away1 | Take the next morning; then back to the usual day2 |
| Boxed warning | None1 | None2 |
Both are swallowed whole with 6 to 8 ounces of plain water on an empty stomach, sitting or standing. The difference is how often and how long you wait: ibandronate once a month with a 60-minute wait, Fosamax once a week with a 30-minute wait.12
The warnings are the same set: esophagus irritation, low calcium, jaw bone death and unusual thigh fractures.12 The ibandronate numbers above come from a trial comparing two doses of ibandronate, not placebo. These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
Your prescriber decides which fits. More detail: ibandronate side effects, Fosamax side effects, the ibandronate and Fosamax dosing schedules, and the Fosamax missed-dose page.