It is sometimes necessary to split tablets into halves or quarters.

A pill-splitter is a simple and inexpensive device to split medicinal pills or tablets, comprising some means of holding the tablet in place, a blade, and usually a compartment in which to store the unused part.

Also, do not split extended-release tablets unless they have a score line and your doctor or pharmacist tells you to do so.

"The decision on whether to split tablets should be between the patient, physician and pharmacist," said Susan Winckler, vice president for policy at the pharmaceutical association in Washington.

A 2002 research study financed in part by the Veterans Affairs Medical Center in Asheville, N.C., found that when elderly patients split tablets, doses deviated 9 percent to 37 percent from those intended.