| Term | Definition |
|---|
| Phenoxybenzamine | nonselective alpha antagonist prototype, irreversible antagonism, antihypertensive |
| Phenoxybenzamine effect | inhibit alpha receptors, reduce peripheral resistance, reflex tacycardia, some blockade of inhibitor effects on NE release, so increase NE release and stimulation of heart, so increase HR |
| Phenoxybenzamine duration | 14-48 hours |
| Phenoxybenzamine tx | pheocrhomocytoma, and BPH |
| Phenoxybenzamine AE | postural hypotension, nasal stuffiness, ejaculatory failure, and priapism via intracavernosal injection. large, rapid dose causes seizures |
| Phenoxybenzamine drug interaction | with epinephrine, unopposed beta interactions, and decrease necrosis |
| Block alpha and beta | First alpha blocker then beta blocker |
| Phenoxybenzamine drug contraindication | posphodiesterase 5-inhibitors b/c potentiation of hypotensive effects |
| Phentolamine | competitive nonselective alpha antagonist, can dose to response, effects other receptors (inhibit 5HT and agonist for M and H) |
| Phentolamine duration | 5-7 hour half life |
| Phentolamine tx | male dysfunction via direct intracavernous injection |
| Phentolamine AE | tachcardia, arrhythmias, and ischemic effects |
| Phentolamine contraindication | coronary heart dz, arrhythmias, and history of peptic ulcer |
| Parazosin | selective alpha1 antagonist, Quinazoline class, prototype, potent inhibitor of cyclic nucleotide phosphodiesterases, increase cGMP and cause arteriolar relaxation, and may induce apoptosis in epithelia and stromal cells of the prostate, without effecting proliferation |
| Parazosin effect | reduce BP, preload and afterload, and available to inhibit NE release so no tachycardia, lowers LDL and triglycerides, and increases HDL |
| Parazosin first dose effect | cause syncopy, administer before bed |
| Parazosin pk | hepatic is extensive, plasma half life longer in congestive heart failurs, onset is for 7 to 10hrs, does not pass through kidneys |
| Parazosin tx | hypertension, BPH (with 5 alpha-reductase inhibitor) |
| Parazosin AE | postural hypotension, intraoperative floppy iris syndrome, relaxation of iris dilator muscle |
| Tamsulosin | selective alpha1A antagonist, receptor only found in prostate, does not induce apoptosis |
| Tamsulosin pk | substrate of CYP2D6 (genetic variation) and CYP3A4, so effected by inhibitors/promoters of these enzymes |
| Tamsulosin AE | less chance of orthostatic hypotension, but still floppy iris syndrome |
| Propranolol | prototype, nonselective beta antagonist, highly lipophilic, reduced bioavailability |
| Metoprolol | 2nd generation beta1 selective blocker. some lipophilicity, lacks membrane stabilizing effect, and has first pass metabolism, extensive hepatic CYP2D6 metabolism, poor metabolizers have more AEs, urinary excretion |
| esmolol | 2nd generation beta1 selective blocker, very short acting, IV only, used in emergencies, lacks intrinsic sympathomemimetic activity and is membrane stabilizing |
| labetolol | 3rd generation non selective beta blocker, with additional actions, blocks alpha1 receptor, brings down BP fast, IV/oral, each isomer has different effects/metabolic rate |
| Metoprolol tx | hypertension, stable angina, acute MI, chronic heart failure |
| Propranolol tx | hypertension, angina, arrythmias, parkinsonian tremors, akathisia |
| labetolol tx | chronic hypertension and hypertensive emergencies |
| esmolol tx | AE of bradycardia, heart failure, or hypotension necessitate rapid withdrawal of drug |
Combine with other sets
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