PEBC: What You Need to Know: Bisphosphonates

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)