Prazosin applications

Prazosin was the first example of a selective O -blocker. Its main application is hypertension, usually in combination with a -blocker and/or a diuretic. Orthostatic hypotension readily occurs as a result of venous dilatation. The problem may be avoided by a gradual increase of the dosage. The drug has a short duration of action and must be administered 2-3 times daily in order to achieve adequate control of blood pressure. 

Similar conclusions could be derived from an investigation of antihypertensive clonidine analogs, with respect to their peripheral hypertensive side effects. For a series of clonidine-related imidazolines, log Papp values were determined in -octanol/buffer at pH 7.4, central antihypertensive activities C2s (molar doses that cause a 25% blood pressure decrease, intravenous application) in anesthesized rats, peripheral hypertensive activities C o (molar doses that cause a 60-mm Hg blood pressure increase, intravenous application) in pithed rats (i.e., rats without central nervous system control), binding affinities IC50ai to ai receptors (replacement of prazosin), and binding affinities IC50+ 10 a2 receptors (replacement of clonidine) [86,87],... 

For the same class of compounds Timmermans determined log Papp values (n-octanol/buffer, pH = 7.4), binding affinities to oti adrenoceptors, ICsoOti (displacement of the oti antagonist prazosin), binding affinities to a2 adrenoceptors, IC5(,a2 (displacement of the 2 agonist clonidine), antihypertensive activities (mediated by a central mechanism) in anesthetized normotensive rats (ED2s%, i v. application), and hypertensive activities (mediated by peripheral a stimulation which, in the absence of central nervous system regulation, causes blood vessel contraction) in... 

An example of the application of LC-MS and UPLC-MS in vitro and in vivo metabolism studies is the study of the metabolism of prazosin (antihypertensive agent being investigated for the treatment of posttraumatic stress disorder). The in vivo metabolism of prazosin in rat was first reported in 1977,[28] metabolites were characterized, though at... 

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