Hello, dey, Just want to reassure your father that dosage has the greatest impact on side effects. My mother has been on 100 mg per day for 25 years, she is 97 (thus, she started on amiodarone at age 72) and has never shown any of the side effects that seem to be constantly trumpeted about. I know that on dosages of 300 - 800 mg there is a much greater chance of negative side effects. But Mom has not had another atrial fib episode in 25 yrs, so it has worked incredibly well and very safely for her. She HAS had the recommended blood tests at check-up ever 6 - 12 months, which is the proper way to do it. Hope this reassures your father that a low dose of 100-200 mg per day might very well work quite well for him, without other issues. Best wishes!