The absorption of the 
bisphosphonates is reduced by food.    
   Recommendations on the timing of 
administration of 
bisphosphonates in relation to food and other drugs vary. Alendronate and risedronate should be given at least 30 minutes before the first food of the day. Clodronate should be given at least 1 hour before or after food, ibandronate should be given with water on an empty stomach at least one hour before the first food of the day, and etidronate and tiludronate should be given on an empty stomach at least 2 hours before or after food.