The IV Bisphosphonates are IV Boniva, Reclast and Zometa. Reclast and Zometa are actually the same drug in different doses for different purposes. Reclast is the one used for Osteoporosis. These are all given by a shot into a vein (IV).
IV Bisphosphonates were developed to be less irritating and to be more reliable than Oral Bisphosphonates. They completely avoid the esophagus and stomach, so heartburn and reflux disease are not an issue. They also avoid the possibility of poor absorption from the stomach. If you take an IV Bisphosphonate, you know that you have the medicine on board and that you are protecting your bones.
IV Boniva is given every 3 months. It is 3 times as much drug as the oral Boniva dose. Reclast is given once every year. It is 12 times as much drug as a monthly dose. These higher doses mean that you must have normal kidney function for these drugs to be safe.
A blood test called Creatinine is used to calculate kidney function or “GFR”. The GFR (Glomerular Filtration Rate) depends on patient size as well as the Creatinine blood test, especially in older individuals. An alternate method involves collecting all of your urine for 24 hours.
Reclast requires a GFR of at least 35. IV Boniva requires a GFR of at least 30. As long as your kidneys are functioning this well, the drugs are safe. Many individuals over 90 and some who are younger no longer have kidney function this good. They may not be able to use IV bisphosphonates. They may need to consider Prolia.
Remember that none of these medications can work without enough Calcium and Vitamin D.
Also IV Boniva, Reclast and Prolia can be dangerous without enough Calcium and Vitamin D.
Jay Ginther, MD
2008 / Revised April 2011