Warfarin Sodium Had a mitral valve replacement with pigs valve in September 2008. Told I needed it and would feel much better. Two weeks later had Atrial Fibrilation and was put on warfarin together with bisoprolol (beta blocker). Was cardioverted in December but am still on Warfarin 7-8mg to keep my INR at between 2-3. I experience such awful side effects, that seeing thig site proved that it was not all in my head. Symptoms, hair loss, bleeding gums, painful legs, weight gain, fatigue, headaches, blurred vision, tender skin, depression etc. etc. I feel depressed and wish I hadn't bothered with the operation, as I feel worse that before!