Term
| phenoxybenzamine (Dibenzyline) |
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Definition
| long-acting non-selective non-competitive alpha-adrenergic blocker; helps prevent severe catecholamine-induced hypertensive episodes that occur in preoperative pheochromocytoma patients (massive release of Epi & NE from tumor cannot overcome its irreversible blockade); also blocks extrasynaptically-located alpha-2 receptors in vascular smooth muscles |
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Term
| Common Side Effects of Alpha-adrenergic Blockers |
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Definition
| nasal congestion, difficulty ejaculating, reflex tachycardia, systemic fluid retention, orthostatic hypotensive symptoms |
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Term
| Side Effects of phenoxybenzamine (Dibenzyline) |
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Definition
| drug that inhibits histamine, serotonin, & ACh receptors; causes miosis (pupils constrict), sedation, drowsiness, vomiting, lethargy; shock & circulatory failure |
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Term
| phentolamine (generic, OraVerse) |
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Definition
| short-acting competitive (reversible) alpha-adrenergic blocker (both alpha-1 & -2); used in diagnosis of pheochromocytoma; used during surgical removal of pheochromocytoma tumor; used to reverse excess acute systemic vasoconstriction & related hypertension produced by IV overdose of NE; used to prevent local dermal tissue necrosis that can occur accidentally at sites of injection of non-specific alpha-agonists; new form of drug used to reverse oral soft tissue anesthesia & related functional deficits resulting from intraoral submucosal injection of a local anesthetic preparation containing a vasoconstrictor (like Epi) |
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Term
| Side Effects of phentolamine (generic, OraVerse) |
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Definition
| drug that causes nausea, vomiting, diarrhea, increased GI motility (bad for ulcers), also may stimulate various non-adrenergic receptors |
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Term
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Definition
| test used to diagnose pheochromocytoma; a marked short-term fall in BP after adminstration of 5 mg suggests presence of pheochromocytoma; normally, 5 mg does not cause such a fall in BP in normal persons |
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Term
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Definition
| prototype selective alpha-1-adrenergic receptor blocker; used in long-term treatment of mild-moderate primary hypertension (usually given with diuretic); used to relax smooth muscle of bladder neck & prostatic urethra, relieving obstructive urinary symptoms of BPH (benign prostatic hyperplasia) |
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Term
| Side Effects of prazosin (Minipress), terazosin (Hytrin), and doxazosin (Cardura) |
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Definition
| drug causes orthostatic hypotension with syncope, usually during 1st day of use ("First Dose Phenomenon"); some salt & water retention; some tachycardia but not much |
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Term
| terazosin (Hytrin) and doxazosin (Cardura) |
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Definition
| newer alpha-1-receptor blockers with much longer half-lives than previous med; treatment of long-term mild-moderate primary hypertension; relaxes smooth muscle of bladder neck and prostatic urethra, relieving obstructive urinary symptoms of BPH |
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Term
| tamsulosin (Flomax) and silodosin (Rapaflo) |
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Definition
| selective alpha-1A-receptor blockers; drugs of choice to treat BPH because they are more specific and have less systemic vascular actions or side effects |
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Term
| Side Effects of tamsulosin (Flomax) and silodosin (Rapaflo) |
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Definition
| less systemic vascular actions or side effects than other BPH meds; still causes abnormal ejaculation due to inhibition of alpha-1A receptors on vas deferens |
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Term
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Definition
| non-receptor subtype-selective alpha-1 blocker; used to treat BPH; able to be uroselective due to accumulation of drug in prostatic tissue |
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