Examples:
alendronate (oral), risedronate (oral), zoledronic acid (intravenous infusion)
*note: etidronate has been discontinued in Canada
Indication: Osteoporosis in men and women
Flexible Dosing:
Once daily: risedronate, alendronate
Once weekly: risedronate, alendronate
Once monthly: risedronate
Yearly (or every 2 years): zoledronic acid
Administration:
-oral bisphosphonates have very poor absorption
-oral: on an empty stomach 30 minutes with a full glass of water prior to the first meal of the day (due to reduced absorption with food or other drinks)
-space apart from other medications
-do not lie down for 30 minutes to avoid esophageal irritation
*except risedronate delayed-release formulation which is taken with food
Adverse Effects:
-esophageal irritation
-GI upset: nausea, diarrhea, dyspepsia, abdominal pain
-muscle aches, joint pains
-rare: atypical fractures of femur
-rare: osteonecrosis of the jaw: more common if cancer, invasive dental surgery or IV bisphosphonates
-rare: hypocalcemia: make sure to supplement with calcium and vitamin D
-caution in renal disease
Drug Interactions:
-make sure to space oral bisphosphonates away from other medications due to reduced absorption
-proton-pump inhibitors and H2-receptor antagonists: associated with more fractures (may be a confounding factor because they can reduce calcium absorption)