Why do oral bisphosphonates have such inconvenient dosing instructions?
Bisphosphonates are very poorly absorbed when given orally by tablet. Even if dosed properly, only 1% to 3% of the medication in the tablet is able to be absorbed and to enter the body. The remainder binds to stomach contents and does not get absorbed. It is for this reason that dosing must be 30 to 60 minutes before breakfast and with only plain water. The first food or drink of the day other than water must be delayed for at least 30 minutes in order to permit absorption. Other dosing schedules lower the effectiveness of the medications. You should drink at least 8 ounces of water when you take the tablet to be sure it goes into the stomach and that there is enough water to disperse the medication. After dosing, you should not lie down for 60 minutes to ensure that the medication does not wash back and cause heartburn symptoms.
