Is catapres (clonidine) safe to lower bp?

To a degree. All medications are not without risk but this one is often used to lower blood pressures that can be difficult to maintain at appropriate levels or those that need to be lowered from dangerous highs. It can cause rebound hypertension, however, meaning that if you are not taking it consistently it can cause your pressure to go even higher. It is not a common first-line treatment for this reason.