Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043352 (xerostomia)
 4,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a single-blind comparative study of the cases of 30 moderately hypertensive patients, clonidine hydrochloride and prazosin hydrochloride had similar effectiveness in lowering blood pressure. Neither agent had significant effects on the renin-aldosterone axis. Addition of polythiazide to prazosin and chlorthalidone to clonidine notably increased the antihypertensive effect of both drugs. Serum cholesterol levels were observed to decrease when prazosin and clonidine were given and to rise when the diuretics were added to the regimen. The patients treated with clonidine were troubled by side effects, particularly drowsiness and dry mouth. Prazosin was better tolerated, with side effects tending to diminish with time. The "first-dose" effect was seen in two patients given prazosin, but it did not limit treatment. Both diuretics induced notable hypokalemia.
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PMID:Prazosin and clonidine for moderately severe hypertension. 36 88

Among the newer antihypertensive agents are the beta-blocking drugs, such as propranolol. These agents are useful as second-step drugs to be used if diuretic therapy alone is not effective. In mild to moderately severe hypertension, propranolol, in does of up to 480 mg/day in combination with a thiazide diuretic, has been found to be effective in over 80% of patients on long-term therapy. This degree of response is essentially similar to that noted with a combination of reserpine and a diuretic agent. Although some observers believe that propranolol produces many fewer side effects than the other step 2 drugs (reserpine and alpha-methyldopa), there are some patients who do experience restlessness, insomnia, and depression. Clonidine may be substituted for another step 2 drug, is of moderate potency, but may not be tolerated by a large number of patients because of the severe dry mouth and drowsiness that it produces. Prazosin appears to be a suitable substitute for hydralazine as an effective vasodialator if thiazides plus propranolol or thiazides plus reserpine or alpha-methyldopa are not effective. In some instances, it many be an acceptable second-step drug because of its alpha-adrenoreceptor-blocking properties. The angiotensin II competitive inhibitors or converting enzyme inhibitors may in the future have some place in the management of hypertension.
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PMID:Propranolol and newer antihypertensive drugs in the management of hypertension. 42 60

Central and peripheral alpha-adrenoceptors play an important role in cardiovascular regulation, and selective alpha 1-adrenoceptor antagonists and alpha 2-adrenoceptor agonists have an established place in the therapy of hypertension. Prazosin is a selective alpha 1-antagonist that is both effective in lowering blood pressure and well tolerated. However, the more recently developed alpha 1-antagonists doxazosin and terazosin offer the advantage of having longer half-lives, allowing once daily administration. Clonidine is a centrally acting alpha 2-agonist whose clinical use has often been limited by the dose dependent side effects of dry mouth and sedation, and the belief that it should be given three times per day. However, recent studies have shown that it has substantial antihypertensive efficacy with minimal side effects at low doses, and that half-life is long enough to allow twice daily administration. An improved understanding of the pharmacodynamics and pharmacokinetics of drugs acting on alpha-adrenoceptors allows a more rational approach to their clinical application.
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PMID:Comparison of pharmacokinetics and pharmacodynamics of adrenoceptor agonists and antagonists as antihypertensive agents. 245 58