My Husband Has Been Taking Warfarin For 7 Years, Due

My husband has been taking Warfarin for 7 years, due to atrium fibrillation and is having trouble keeping his INR levels at the correct level. Have heard there are other drugs better than Warfarin. Are you able to give me the names of these and side affects related to them please? My husband also loves the outdoors and the sunshine so the drug would have to allow him to continue enjoying the sunshine.Thankyou, Gay