Posted by ed_uk2010 on February 7, 2012, at 11:08:07
In reply to Re: Adding Parnate and prazosin. » ed_uk2010, posted by SLS on February 6, 2012, at 7:40:25
I just had a look in one of my textbooks. It says 'The alpha-1c designation has been removed due to an unfortunate confusion in the literature'.
It seems that alpha-1a and alpha-1b receptors are both found in the brain, but have a different distribution. The alpha-1d is a novel receptor found in the rat aorta.
Alpha-1a is the major alpha receptor in the prostate, and partially selective antagonists such as tamsulosin are widely used for BPH. Lower affinity for alpha-1b apparently equals fewer hypotensive adverse effects.
I wasn't able to find anything about the subtype selectivity of TCAs at alpha receptors. They are generally described vaguely as alpha-1 antagonists. I suspect they are not very selective.
poster:ed_uk2010
thread:1005781
URL: http://www.dr-bob.org/babble/20120202/msgs/1009561.html