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Definition
| At low doses -> Beta effects (vasodilation), at high doses -> alpha effects (vasoconstriction). At the pancreas the beta cells are inhibited via alpha-2 Rs (predominant effect) but enhanced by beta-2 Rs. Metabolites are metanephrine & VMA. NB that weirdly mydriasis doesnt occur. Given parentally, and cause it is broken down so fast in blood it has a short T 1/2. In hyperthyroid pts there is up-regulation of adrenergic receptors, with cocaine there is blocking of reuptake, polar thus no crossing BBB |
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Definition
| Acts mainly on alpha Rs but even then is less potent then Epi |
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Definition
| At low doses acts on D1 Rs in the BV's at the renal (leads to increases GFR and thus Na+ excretion), coronary and mesenteric beds to cause vasodilation via Gs, at high doses has an inotropic effect via beta-1 Rs & also acts on alpha-1 Rs, does not cross BBB |
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Term
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Definition
| Dopamine agonist, used in-pts for short-term use on severe hypertension, given IV continously |
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Term
| Oxymethazoline & Xylomethazoline |
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Definition
| Alpha-agonist, used extensively as a topical nasal decongestant (work by acting on alpha-1 Rs on venous capacitance in nasal tissue thus reducing the nasal mucosa volume!!!) |
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Term
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Definition
| Lack the catechol -OH grp thus longer T 1/2, Alpha-1 R agonist, used for: nasal decongestion, a mydriatic, to terminate supraventricular tachycardia |
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Term
| Phenylephrine & Pseudoephedrine |
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Definition
| oral preps for nasal congestion, usually sound in combo w/ H1-histamine antagonist |
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Definition
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Term
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Definition
| Partial alpha-2 agonist, acts centrally to supress sym outflow, when givin IV it causes an acute raise in BP (acts on alpha-1), this transient rise is not seen when given orally |
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Term
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Definition
| Is taken up by noradrenergic neurons and converted to alpha-methylnorepinephrine which then acts centrally like clonidine, cause of its safety is used to Tx hypertension in pregnancy |
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Definition
| Highly selective alpha-2 agonist given ocularly to Tx IOP via reducing aqueous prod & increasing uveoscleral outflow (HOW???) |
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Term
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Definition
| Beta-agonist, less hyperglycemia than w/ Epi cause of strong beta activation of islet cells, NB that both epi and this Rx are equally effect in releaseing free F.As, used rarely for asthma but more of an emergency stimulant to the heart, usually taken sublingually, is partly broken down by COMT but not by MAO |
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Term
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Definition
| Given as a racemic mixture (having both the - isomer: alpha-1 agonist and a weak beta-1 agonist; & + isomer: alpha-1 antagonist and a potent beta-1 agonist) => this results in a net canceling of the alpha-1 and an increase of beta-1, used to manage acute heart failure via increasing CO w/out increasing heart-rate and additionally doesnt increase the O2 demand thus at an advantage over other sym Rxs. A/Es: bad to use in Atrial fibrillation as it increase AV conduction, tolerance may develop over time |
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Term
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Definition
| Beta-2 agonist, has a resorcinol ring thus is not a substrate for COMT hence longer duration, there are multiple routes in but used parenterally to Tx status asthmaticus. Also used as a bronchodilator & to reduce uterine contractions in premature labour |
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Term
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Definition
| Beta-2 agonist, similar properties to terbutaline, widely used as an inhalent to relieve bronchospasm |
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Term
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Definition
| Beta-2 agonist, duration of 12hrs after inhalation thus not to be used along to Tx bronchospasm |
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Term
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Definition
| Long-acting beta-2 agonist similar to salmeterol |
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Term
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Definition
| Lack the catechol -OH grp thus longer T 1/2, it displaces catecholamines from the vesicles, weakly inhibits MAO, and prevents reuptake, it also has weak post-synaptic activity, it has a central stimulatory effect and this used to Tx depression, narcolepsy & even supress appetite, A/Es: include fatigue & depression after the initial central stimulation |
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Definition
| Analogue of amphetamine, used to Tx ADHD |
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Term
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Definition
| Not used clinically, found in foods like riped cheese and Chianti wine, is a normal metabolite of tyrosine, normally oxidised by MAO (thus contraindicated in pts taking MAO inhibitors as it can lead to a serious vasopressor episode - recall that tyramine like amphetamine displaces stored NE) |
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Term
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Definition
| Lack the catechol -OH grp thus longer T 1/2, taken orally, enters CNS, acts on both adrenergic Rs and releases NE, eliminated unchanged in urine, slower onset thus used prophylactically in Tx-ing chronic asthma. Strangely thus Rx plus an AchEI aids in myasthenia gravis. Furthermore it stimulates CNS mildly and helps with athletic performance, banned from herbal tea cause of CVS probs. Instead used to Tx: asthma, nasal decongestion, raise BP, but now being replaced by newer Rxs w/ less side-effects |
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Term
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Definition
| One of the four ephedrine enantiomers, is an over the counter Rx for decongestion |
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