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Definition
| Alkyates irreversibly to alpha (slightly more to 1) Rs, chemically close to nitrogen mustards, also blocks H1, M and serotonin Rs & inhibits NE reuptake, used to be used to Tx hypertension but not anymore, now used to Tx chronic pheochromocytoma or just before operation, a beta blocker may be given after this alpha blocker (given in this order so as to ???). NB the concept of Epi Reversal, which basically says that in the presence of an alpha blocker like Phenoxybenzamine, only the beta effects of Epi occur leading to this phenomenon. |
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Definition
| Reversibly blocks both alpha-1 & 2, causes postural hypotension, blocks serotonin Rs and is an agonist to M, H1/2 Rs, can cause arrhythmias & cause anginal pain (contraindicated in pts with decreased coronary perfusion), used to prevent or control hypertension in pheochromocytoma pts (helps Dx it via the phentolamine test). Strangle indicated for the prevention of dermal necrosis after inadverent extravasation of NE. Used in stimulant OD (cocaine, amphetamine, ephedrine), also an adjunct for cocaine-induced acute coronary syndrome to REVERSE CORONARY ARTERY VASOCONSTRICTION (?). Used in hypertensive crisis caused by rapid withdrawal of sympatholytic antihypertensive Rxs (eg. clonidine). Importantly its used in hypertensive crisis caused by interaction btw MAOI and tyramine (or other sympathomimetic amines) |
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Definition
| Prototype alpha 1 blocker, relaxes both arterial and venous SM thus reflex tachycardia doesnt occur, may also act on CNS to supress sym outflow, it also interestingly decreases LDL & TAGs, while increasing HDL, approved for Tx-ing hypertension (but not Rx of choice), gives "first dose effect" |
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Definition
| Analog of prazosin, longer T 1/2, approved for Tx-ing hypertension & BPH |
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Definition
| Is a subselective alpha-1 blocker (alpha-1A, which predominates in the genitourinary SM) thus not giving you orthostatic hypertension as it happens in prazosin other nonsubtype alpha-1 blockers. => approved for BPH & little effect on BP |
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Definition
| Alpha-2 Blocker, thus more insulin, used in the past to Tx erectile dysfunction but now replaced by the 5-phosphodiesterase inhibitors. NB that this can abruptly reverse the antihypertensive effects of an alpha-2 agonist (such as clonidine) thus a serious Rx interaction |
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Definition
| Prototype for beta blockers, slows heart rate and contractility (this effect is modest until sym system is activated), will cause reflexive vasoconstriction in normotensive pts, in hypertensive pts it will lower both systolic and diastolic in a few days (besides the effect on the heart it also produces these effects via blocking renin release vi beta-1), no postural or exercise-induced hypotension as alpha Rs are unaffected, contraindicated in asthmatic pts, decreases glycogenolysis & glucagon secretion thus closely monitor type 1 diabetics as they may have pronounced hypoglycemia after insulin injection (NB that the normal hypoglycemic tachycardia is masked; also insulin release is only rarely impaired), aids with migraines & hyperthyroidism (?), cause it decreases O2 requirement of the heart it can be used to chronically manage stable angina (not for acute management) this allows them to tolerate moderate excercise as seen in EKG, NB however not indicated in variant angina, aids w/ post MI if given immediately can reduce the size and help w/ recovery, also given prophylactically for the 2nd MI (MOA???), thus also decreases sudden arrhythmic death after MI (NB that if withdrawn to fast will induce an arrhythmia, worsen angina or hypertension cause of the up-regulation of beta Rs). Interestingly it used for performance anxiety. Beta-3 activate hormone-sensitive lipase thus increasing free F.As. Via unknown MOA TAGs are elevated & HDL are decreased w/ no change of LDLs, it has a low liposolubility however it still has some bad CNS effects |
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Definition
| Long duration thus used for long-term management of angina pectoris and hypertension too |
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Definition
| Decreases IOP via blocking beta-2 (secretes aqeuous humour) w/out affecting focus of eye or pupil size as cholinergics do, used to Tx hypertension, prophylaxis for migraines |
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Term
| Atenolol, Metoprolol, Esmolol |
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Definition
| Decrease BP and increase exercise tolerance in angina, better for pts w/ pulmonary impairment, useful in diabetic pts who take insulin or oral hypoglycemics, is ultra short acting as it has an ester bond that is rapidly broken down by the RBC's esterase to a metabolite w/ less affinity thus given IV continously, has a T 1/2 of 10 mins |
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Term
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Definition
| Competitive alpha-1 & beta blocker, useful in Tx hypertension of pheochromocytoma & hypertensive emergencies, can also be used to Tx hypertension that is accompanied by tachycardia (not bradycardia as a pure alpha blocker would be best), A/Es: it has shown hepatic injury in a limited no. of pts |
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Definition
| alpha-1 & non-subtype selective beta blocker, has antioxidant properties, used to Tx hypertension & congestive heart failure |
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| Partial agonist (ISA) for beta Rs, used in hypertension, cause of its reduced effect may be beneficial to pts w/ diminished cardiac reserve (???) or a propensity for bradycardia, also have a lesser effect on lipid and carb metabolism thus a valuable Tx plan for diabetics, however clinical significance of ISA is still uncertain (???) |
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Term
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Definition
| Acts presynaptically to inhibit NE syn., competitive inhibitor of tyrosine hydroxylase thus blocking the syn of dopamine and thus the others, this is used as an adjuvant to phenoxybenzamine (alpha-blocker) in management of malignant pheochromocytoma or used preoperatively |
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Definition
| Acts presynaptically to inhibit NE storage & release via irreversibly damaging VMAT thus no dopamine gets in to the vesicle to make NE, slow onset but long axn, in the past was used to Tx hypertension |
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Definition
| Acts presynaptically to inhibit NE storage & release via being transported into the nerve by NET/ uptake 1 and once inside would displace NE from the vesicles, in a second but more unknown MOA it prevents action potentials from releasing NE, strangle the A/Es are orthostatic hypotension & male sexual dysfunction, its too polar to enter the CNS, was used in the past to Tx hypertension |
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Term
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Definition
| Inhibits NE reuptake, most potent at blocking dopamine transporters (DAT) but at higher conc. will block SERT & NET, this allows monoamines to accumulate in the synaptic space, in the CNS it prevents Dopamine reuptake into pleasure centers in the limbic system thus inducing intense euphoria, additionally blocks voltage-gated sodium channels thus used as a local anesthetic |
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Term
| MAOIs (phenelzine or moclobemide - Tx depression; Selegiline - Tx Parkinsons) |
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Definition
| Prevent deamination of catecholamines thus they build up in the synaptic cleft |
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Term
| TCAs (imipramine & amitriptyline) |
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Definition
| Inhibit NET & SERT thus allow NE and 5-HT to accumulate in the synaptic cleft |
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