I just started taking Fosamax for osteoporosis. My doctor told me to avoid eating before taking the drug and to remain sitting up for 30 minutes after taking it. Why is this important?

Fosamax is the trade name for a group of drugs called bisphosphonates. These drugs keep bone cells from being absorbed by the body or destroyed. They are used to prevent and treat bone diseases such as Paget’s disease, bone cancer, and osteoporosis.

Bisphosphonates taken in pill form have a low absorption rate. This means that much of the drug passes through the body without being used. Absorption of Fosamax is even less when there is food or liquid in the stomach. Taking the drug without food and water helps ensure its proper use.

Bisphosphonates can also cause intestinal upset and ulcers. To avoid inflammation and ulcer, patients are advised to sit or stand after taking oral bisphosphonates. This helps the drug pass through the stomach more quickly.

See your doctor if you follow all of these instructions and still have problems. Nausea, vomiting, taste disorders, diarrhea, and constipation can be helped with a change in drug or dosage.