Question about GHB and Hypertension

Why do they say not use GHB if you have hypertension or severe hypertension? Do they mean if you are going to be using GHB heavily? Because GHB slows heart rate (bradycardia) and lowers blood pressure, so why shouldn't you use it if you are hypertensive? Anyone care to comment. The only reason I can think of is if using GHB heavily can result in negative withdrawal symptoms like high blood pressure, tachycardia, and shaking. Anyone else comment?

Thanks