Nonselective blockers (alpha 1, alpha 2)
Phentolamine and phenoxybenzamine
- both used for pheochromocytoma induced BP and hypertensive emergencies
- important to note that phenoxybenzamine is the only irreversible alpha blocker!
mn
- PHEochromocytoma, PHEntolamine, PHEnoxybenzamine
- to remember phenoxybenzamine being the only irreversible alpha blocker, I think of an ox; phenOXybenzamine. An ox is very resistant to moving anywhere you want it to.
Selective blockers
1) alpha-1 selective "-zosin drugs" (prazosin, terazosin, doxazosin)
- high BP, and urinary retention in BPH
mn
- I just think of ppl in a highly stressful situation (ie. burning building, seeing a shark while swimming). They have high BP and when your SANS is acting up, all blood diverts to the vital organs (muscles, brain, heart...no time for urination, defecation, etc)
- when they see the ZOrroSign (for zosine), they are relieved b/c of Zorro to the rescue! Hope you've all seen Zorro!
Side Effects
- phentOlamine, phenOxybenzamine, "-zOsins" cause OrthOstatic hypOtension
(all alpha blockers except alpha 2 b/c they don't vasodilate)
- once you understand the mechanism of these drug classes, the other side effects are easy to understand, so we can go over them during the meeting. But Orthostatic hypotension is a very important one!
2) alpha-2 selective; Mirtazapine
- it fights depression (depression caused by under stimulation of SANS)
mn
- I think of Mr.Tazer zapping a tazer to your head to stimulate the SANS and knock you out of depression
p. 97 in Pharm Recall has mirtazapine.
ReplyDeleteI think the side-effects listed in First Aid are due to its interaction with serotonin receptors, so we might encounter it later in the course.