My suggestion is to see a doctor of Alternative Medicine for advice on this. I will tell you if you go the red yeast Rice way the Buy Nature's Plus Herbal Actives Red Yeast Rice -- 600 mg - 120 Vegetarian Capsules.
Red yeast rice isn't an herb, it's a food, though that's a small quibble. By itself, it's not that strong, and is usually used in combination with other things to cut cholesterol, including exercise and dietary changes. As to contraindications, you'll have to research that. None that I know of with what you're taking, but this gets complicated since nobody's really researched actual use of natural remedies in conjunction with meds, meaning it's largely theoretical based on the active ingredients in the different substances. I doubt a naturopath would know, and I know a doctor wouldn't know, so it's something you can google and see what you can learn or contact the American Herbal Products Association and see if they be of help in finding the answer. Personally, I like Solaray's combination of red yeast rice with guggul, an ayurvedic herb also helpful in cutting cholesterol, but without combining it with diet and exercise changes you're unlikely to get the results you want.