Posted by Ueli (195.162.170.200) on January 05, 2001 at 20:56:54:
In Reply to: Questions ???? posted by Tami on January 05, 2001 at 18:58:06:
Hi Tami,
High blood pressure is often caused by constricted blood vessels. By relaxing the smooth muscles around, the vessels return them to 'normal' size and the BP drops.
As our vessels are (in general) not over-constricted, the lowering of BP is no concern for clusterheads.
However, the reduction of Ca++ in the smooth muscles has another effect: It makes them sluggish to respond to input signals. This feature is what makes Verapamil useful to prevent CH attacks: The wrong signal to expand the vessels is largely ignored, and the positive feedback loop (that would otherwise lead to the rapid raise of an attack) is broken.
Beta blockers are often useful to prevent migraines, but hardly make a dent for CH. But calcium channel blockers are the preventative of first choice for CH.
PFNAD's
Ueli