Speaking as someone who has not taken this combination but is meant to be taking this combination (at 10mg zolpidem and 0.1 clonidine to start with)... I think this is probably safe as long as you lower your doses. The doctor who prescribes these meds to be is confident they're safe together, the pharmacist I spoke with seemed confident they were safe together, and my mother has read things where apparently they just work lovely together for people with certain subtypes of postural orthostatic tachycardia (... though you are probably not taking them for this). If you're someone who has low blood pressure naturally though, you probably shouldn't touch them.