The oral absorption of
bisphosphonates is significantly reduced (90% reduction with clodronate) by aluminium/magnesium hydroxide. Other polyvalent cations, such as zinc, are expected to interact similarly.
Bisphosphonates should be prevented from coming into contact with
zinc. Recommendations on the timing of
administration of
bisphosphonates in relation to food and other drugs varies. Alendronate and risedronate should be taken at least 30 minutes before taking the first food or drink of the day, clodronate should probably be taken at least 1 hour before or after zinc, ibandronate should be taken 1 hour before zinc, and etidronate and tiludronate should be taken at least 2 hours apart from
zinc.