Yes, an anticoagulant for A-fib and if it is uncontrolled (over 100) they usually use Cardizem until it is controlled.
This question sort of depends upon what type of fibrilation you are experiencing. Often, with atrial fibrilation, one is prescribed a blood thinner to lessen the chances of blood clots, and sometimes an antiarrhythmic is prescribed to lower the frequency of a-fib episodes.
You should speak to your doctor to decide the best course of treatment for you based on your specific situation.