My new insurance company will not approve my use of Vytorin, so my physician is prescribing Zetia and what the nurse I think said sounded Cymbystatin, but I'm unable to find this listed. What is the spelling of these two new replacement drugs for me, and what are their side effects? I'll be 79 in March, have asthma and monthly take IVIG infusions for my suppressed immune system. Otherwise I'm in generally good health, taking three low-impact flexibility classes a week. I'm Rosemary.