alendronat

Alendronat, or alendronate, is a nitrogen-containing bisphosphonate used to treat and prevent osteoporosis in adults and Paget's disease of bone. It inhibits osteoclast-mediated bone resorption, partly by blocking farnesyl pyrophosphate synthase in the mevalonate pathway, reducing osteoclast activity and survival and increasing bone mineral density over time.

Indications include postmenopausal osteoporosis, osteoporosis in men, glucocorticoid-induced osteoporosis, and Paget's disease.

Administration is oral. Take with a full glass of water first thing in the morning after an overnight fast; do not eat or drink for at least 30 minutes, do not lie down, and remain upright to reduce esophageal irritation. Separate from calcium, antacids, and iron by several hours.

Contraindications include hypocalcemia, esophageal abnormalities, active upper GI disease, inability to remain upright for 30 minutes, and severe renal impairment; pregnancy is discouraged.

Common adverse effects are gastrointestinal symptoms; rare events include esophagitis, osteonecrosis of the jaw, and atypical femoral fractures with long-term use. Adequate vitamin D and calcium are advised.

Interactions: calcium, antacids, and iron reduce absorption; separate dosing.

Pharmacokinetics: low oral bioavailability; localizes in bone with a long skeletal half-life; eliminated by the kidneys.

Brand names include Fosamax; generics are available as alendronate.