Scelective α-1 AGONISTS: (PPM)
Alpha receptor agonist and antagonist the alpha receptor agonist and antagonist may be alpha one selective alpha two selective non-selective alpha one alpha two and non-selective alpha beta receptors now selective alpha 1 agonist mnemonics is ppm parts per million phenylephrine pseudoephedrine and methoxamine the alpha one agonists what are the uses they are
Used in hypotension hemostasis and nasal congestion so what are the effects of alpha 1 agonists alpha 1 agonists like phenylephrine primarily act on vascular smooth muscle causing vasoconstriction so they increase the blood pressure they increase the peripheral vascular resistance increase various return increase arterial and diastolic blood pressure but they
Cause reflex body cardia they increase the glycogenolysis and decrease the renin release so alpha one agonist stimulation will cause vasoconstriction increased peripheral resistance in increase in blood pressure increased glycogenolysis the only function that is decreased by alpha-1 agonist is that of the run-in release selective alpha-1 antagonist or alpha
One blockers what do they do they decrease the peripheral resistance and decrease the blood pressure opposite to that of alpha one agonist and they do this by dilating both the resistance and the capacitance vessel arteries and veins so what are the example of alpha one antagonist pneumonics is dpt doxazosin processing and terrazycin processing is the alpha one
Antagonist that decreases the blood pressure by dilating both resistance and capacitance vessels as i already told so what’s the side effect of processing there is a first dose postural hypotension that may cause myocardial infarction and stroke and this other side effect is nasal stiffness processing is also used in vasospastic burgers disease causing both
Dilatation now alpha 2 agonists and antagonists selective alpha 2 agonists the inhibited sympathetic center in the brain stem so they are sympatholytics so alpha two agonists examples are clonidine catapress alpha methyl dopa alderman recirpine and guanificient so we just did the alpha two receptor stimulation action that they decrease everything decreased blood
Pressure lipolysis insulin secretion for example so alpha 2 receptor stimulation will suppress the release of noradrenaline so they decrease the peripheral resistance and decrease the blood pressure they are used in the treatment of number one hypertension and number two they are also used in adhd attention deficit hyperactivity disorders the centrally acting
Alpha 2 agonists are used in autonomic neuropathy that occur due to baroreceptor denervation alpha 2 agonists cause meiosis so they are used in glaucoma remember alpha 1 causes pupillary dilatation whereas alpha 2 stimulation or agonists cause meiosis so used in glaucoma alpha 2 agonists on withdrawal they may produce rebound hypertension because normally they
Produced hypotension so they are used in hypertension but withdrawal of alpha 2 agonists chronology may cause rebound hypertension selective alpha 2 antagonist example is yoimbin and mirtazipine yohimbine is used in postural hypotension now non-selective alpha 1 and alpha 2 blockers formula is ppt parts per trillion or ppt centrolamine regin phenoxybenzamine which
Has a slow prolonged duration of action phenoxybenzamine slow prolonged duration of action and number three is throlazoline priscoline so the alpha 1 and 2 blockers combined non-selective alpha 1 and for 2 blockers are phentolamine phenoxy benzamine and thorazoline priscaline the non-selective alpha-1 and alpha-2 blockers are primarily used in few chromosytoma
Now non-selective alpha beta blockers they block both alpha and beta receptors examples are labita load and carbide law
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Alpha agonists and antagonists By USMLE exam gym
