No problems. ACEI's are great drugs in combating HTN and if you know the MOA than you should know they do alot more than just reduce BP (ACEI's provide a cardioprotective effect), they play a big part in the entire neurohormonal control of HTN, as well as provide beneficial effects on blood vessels via bradykinin etc. (may be related to the dry cough experienced in some). ACEI's can also cause hyperkalemia, and so can AAS so be aware of this. But all in all I feel ACEI's one to be one of the superior drugs in treating HTN. You wouldn't want to use clonidine (Catapres, I think this is what you meant) for HTN, it is useful but too many negative sides and is not practical in uncomplicated HTN. I don't know what catapril is, but if you are thinking of Captopril...it is also an ACEI, but with a much shorter half-life than Altace and requires 2-3 x daily dosing instead of one with Altace. All in all, if I had to choose 1 drug for primary uncomplicated HTN: ACEI's or Beta-blockers (both w/wo thiazide diuretic) are IMO optimal. There are many drugs out there ,and no doubt all work great to some extent, but both the beta-blockers and ACEI's have proven cardioprotective effects in conjunction with good antihypertensive effects, and if tolerable are great choices.