Term
Centrally Acting Sympatholytics
(Methyldopa, Clonidine) |
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Definition
| Reduce sympathetic outflow while maintaining baroreceptor action. |
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Term
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Definition
Metabolite replaces norepi in vesicles. Acts by stimulating central alpha adenoreceptors, reducing TPR.
Primarily used during pregnancy.
Action persists after drug leaves circulation.
Causes sedation and possibly lactation in men and women. |
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Term
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Definition
Binds medullary alpha receptors. alpha2>alpha1. Reduces sympathetic and increases parasympatheitic tone. Reduces heart rate and TPR.
Dry mouth and sedation common.
Withdrawal can cause hypertensive crisis. |
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Term
Adrenergic Neuron-blocking Agents
(Guanethidine, Reserpine) |
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Definition
| Prevent release of norepi from postganglionic sympathetic neurons. |
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Term
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Definition
Replaces norepi in postganglionic vesicles, preventing norepi release. Action inhibitied by cocaine, amphetamines, and tricyclic antidepressants.
Postural and exercise hypotension. |
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Term
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Definition
Blocks uptake of biogenic amines into vesicles. Affects NE, DA, and 5-HT throughout body.
Sedation, depression, parkinsonian symptoms. Rarely used. |
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Term
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Definition
Nonselective beta blockade. Decreases CO. Inhibits beta1 induced renin production.
Withdrawal syndrome possible.
This drug has been largely replaced by metoprolol and atenolol. |
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Term
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Definition
Cardioselective beta blockers. Beta1 selectivity.
Less bronchial constriction than propanolol. |
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Term
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Definition
Nonselective beta blocker.
Excreted in urine. |
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Term
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Definition
Partial beta agonist. Greater agonist activity at beta2 receptors.
Good for patients with bradyarrhythmias or PVD. |
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Term
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Definition
Beta and alpha antagonists.
Reduce systemic vascular resistance without reducing CO or heart rate.
Good for HTN with pheo. and hypertensive emergencies. |
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Term
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Definition
Selective beta1 antagonist.
IV only.
Used for operative and postoperative HTN and sometimes hypertensive emergencies. |
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Term
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Definition
Selective alpha1 blocker. Reduces TPR without reflex tachycardia. Selectivity allows NE to feedback inhibit itself via alpha2 receptors.
Beneficial effects with prostatic hyperplasia. |
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Term
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Definition
| Primarily relax arteriolar smooth muscle. Leave baroreceptor action intact, so less postural hypotension. |
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Term
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Definition
Arteriolar dilator.
Metabolized by hepatic acetylation, so can cause lupus-like syndrome in slow acetylators.
May cause reflex tachycardia. |
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Term
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Definition
Arteriolar dilator. Acts by opening K channels, stabilizing resting potential.
Must be combined with beta blocker and loop diuretic.
Topical form is Rogaine. |
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Term
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Definition
Parenteral venous and arteriolar dilator.
Increases CO in patients with heart failure due to decreased afterload.
Used in emergencies.
Sensitive to light.
Cyanide is a metabolite and can accumulate. |
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Term
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Definition
Long acting IV arteriolar dilator.
Opens K channels.
Extensively binds albumin, so use smaller dose in patients with renal failure. |
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Term
Calcium Channel Blockers
(Amlodipine, felodipine, nicardipine, nifedipine, verapamil, clevidipine) |
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Definition
Arteriolar dilators.
Inhibit Ca influx into smooth muscle cells.
May cause reflex tachycardia, so CO is preserved. |
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Term
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Definition
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Term
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Definition
Loop diuretic.
Used with severe HTN, renal insufficiency, heart failure, and when other drugs with Na retaining properties are used. |
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Term
Ace inhibitors
(Enalapril, Captopril, Lisinopril, Quinapril) |
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Definition
Inhibit conversion of AT1 to AT2.
Decrease TPR and Na retention.
Prodrugs converted to active agents by hepatic hydrolysis.
No reflex tach.
May cause dry cough due to bradykinin increase.
Contraindicated during pregnancy. |
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Term
Angiotensin Receptor Blockers
(Losartan, Valsartan, Candasartan) |
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Definition
Block AT1 receptor.
No effect on bradykinin, so no cough.
Greater blockade of AT effects because there are more enzymes that convert AT1 to AT2 than just ACE.
Contraindicated in pregnancy. |
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Term
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Definition
| Binds proteolytic site on renin, preventing conversion of angiotensinogen to AT1. |
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