I Have Been On Niacin 1,000 Mg Daily And 20

I have been on niacin 1,000 mg daily and 20 mg of crestor daily for 2 years. My doctor took me off the niacin and increased my crestor to 40 mg. My Ldl went up and we discussed putting me back on niacin and 20 mg crestor. He wanted me to start with 50 mg niacin for 3 weeks and then increase to 1000. When I picked up the samples, I noticed they are Ranolazine 500mg, not niacin. In the literature provided it doesn't mention anything about the flushing niacin causes so I am suspicious that this new drug is not what I need. Are Ranolazine and Niacin the same drug? Do they cause the same side effects? Are the interchangeable?