Pharmacology: Pharmacokinetics: Absorption: The oral mean bioavailability of alendronic acid in women was 0.64% for doses ranging from 5 to 70 mg when administered after an overnight fast and two hours before a standardised breakfast. Bioavailability was decreased similarly to an estimated 0.46% and 0.39% when alendronate was administered one hour or half an hour before a standardised breakfast. In osteoporosis studies, alendronate was effective when administered at least 30 minutes before the first food or beverage of the day.
Distribution: Alendronic acid transiently distributes to soft tissues but is then rapidly redistributed to bone or excreted in the urine.
Biotransformation: There is no evidence that alendronate is metabolised in humans.
Elimination: Alendronic acid, approximately 50% was excreted in the urine within 72 hours and recovered in the faeces.