Oval white tablet imprinted 20 on one side and a four-pointed star on the other side is 20 mg Bextra, a nonsteroidal anti-inflammatory drug used to treat arthritis.
Bextra was taken off the US market on April 7, 2005, due to the possibility of increased risks for heart attacks and strokes. It's in the same class of drugs as Vioxx which was also withdrawn from the market in late 2004.
I'm not a pharmacist or a medical doctor. This message is not medical advice nor is it an offer to provide medical advice. All drug identifications should be validated by a licensed MD or pharmacist.