Hi and welcome to HCM.
I suggest ot to take it until your liver enymes stabilize.it is much more important to protect your liver than to lower your lipids
blood levels. so i am sure you can wait with niaspan bit more. also try to find the cause of elevated liver enymes such as fatty liver
. YOu should treat it by changing dietary and lifestyle habits. Do exercise, avoid alcohol, smoking
, fats, fast food and carbonated drinks. Eat more fruit and vegetables, boiled meat and follow some of hepatoprotective diets. Findings usually improves on such measures. If not, then some medicines can be prescribed.
Wish you good health. Regards