Hi Sophia68,
As far as I understand Revlimid can cause thrombosis - blood cloths - and your dad's doctor is perhaps trying to prevent that.
"Venous thromboembolic events (predominantly deep venous thrombosis and pulmonary embolism) have occurred in patients with MM treated with lenalidomide combination therapy and patients with MDS treated with lenalidomide monotherapy."
http://www.revlimid.com/hcp/hcp-home.aspx
Kind regards
Birgitta-A
72 yo, MDS Interm-1 dx 2006, tx dependent since dx, Thalidomide and Prednisone since June 2010 with good effect, Neupogen for low white blood cells and Exjade for iron overload.