My father's coumadin prescription

  Dear Doctors:  My father is 73 years old.  He is currectly taking four different medications:  mestinon, lanoxin, coumadin, and atenolol.  He and my family are extremely frustrated because we believe the coumadin prescription is causing him to have stiffness in his joints making it hard for him to walk, stand up from sitting, get in and out of cars...  We think it is the coumadin because whenever he is off of the medication even for a very short period of time, he can move as if he is a vibrant 20 year old.  His doctors laughed when he told them of this.  
  He underwent an MRI and other tests to see if it might be Parkinsons disease but he has no other parkinson-like symptonns.  He is physically fit and has a personal trainer working with him several times a week.  
  Have you ever heard of coumadin having these side effects?  Is there a possibility that it is the interaction between the four drugs together?  Is there another blood thinner he could try that is as effective as coumadin?
  I would appreciate any suggestions you might have.  My family and I feel that we need to become proactive in fighting his situation.
  Thank you.

[Cleveland Clinic, MD]

Dear Betsy,
Thank you for your question. I am sorry to hear of your frustration and you should share your feelings with your father