Antihypertensive drugs vasodilator

Another quinazoline, prazosin (1040), is now a widely used antihypertensive drug, acting by vasodilation (77MI21300, B-81MI21301) its preparation is outlined in the patent literature (72NEP7206067). 

Balazs, T. (1981). Cardiotoxicity of adrenergic bronchodililator and vasodilating antihypertensive drugs. In Cardiac Toxicology, Vol. II (Balazs, T., Ed.). CRC Press Boca Raton, FL, pp. 61-73. 

Minoxidil is a peripheral vasodilator that directly relaxes vascular smooth musculature, thus, lowering systolic and diastolic pressure. Its action is linked to the activation of calcium channels. Open calcium channels cause hyperpolarization of smooth muscle cells, which in turn, reduces the flow of calcium ions into the cell, which is necessary for supporting vascular tonicity. However, when taking minoxidil, tachycardia, elevated renin secretion, and water and sodium ion retention all appear simultaneously with hypotension. Because of potentially serious side effects, it is used only for severe hypertension that does not respond to treatment with other drugs, and absolutely in combination with two other antihypertensive drugs. A synonym of this drug is loniten. 

The p-blockers are quite popular antihypertensive drugs. They are well tolerated, and serious side effects are seldom observed. When used alone over several weeks, p-blockers produce a signihcant reduction in blood pressure in approximately 30% of patients with mild to moderate hypertension. Thus, -blockers can be employed as a first step in the management of high blood pressure. However, they are often used in conjunction with a diuretic when therapy with a single agent is not satisfactory. The combination of a p-blocker, thiazide diuretic, and vasodilator provides signihcant control of moderate to severe hypertension in approximately 80% of patients. 

Vasodilators work best in combination with other antihypertensive drugs that oppose the compensatory cardiovascular responses. (See Resistant Hypertension Polypharmacy.)... 

Systemic heat Large whirlpool Hubbard tank Decreased muscle/joint stiffness in large areas of the body Opioid and nonopioid analgesics skeletal muscle relaxants Severe hypotension may occur if systemic hot whirlpool is administered to patients taking peripheral vasodilators and some antihypertensive drugs (eg., alpha-1 antagonists, nitrates, direct-acting vasodilators, calcium channel blockers)... 

Phenothiazine neuroleptics (e.g. chlorpromazine, thioridazine) + vasodilators and antihypertensive drugs —> increased hypotensive effects due to increased peripheral vasodilation. 

Hydralazine was one of the first orally active antihypertensive drugs marketed in the United States. Its structure is shown in Figure 12.4. Initially, the drug was used infrequently because of its propensity to produce reflex tachycardia and tachyphylaxis. However, with a better understanding of the compensatory cardiovascular responses that accompany use of arteriolar vasodilators (the drug has little or no effect on venous smooth muscle), hydralazine was combined with sympatholytic agents and diuretics with greater therapeutic success. 

GLYCOPROTEIN lib/ Ilia INHIBITORS ANTIHYPERTENSIVES AND HEART FAILURE DRUGS-VASODILATOR ANTIHYPERTENSIVES t risk of bleeding when eptifibatide ortirofiban is co-administered with iloprost Uncertain at present Closely monitor effects watch for signs of excess bleeding... 

THIAZIDES ANTIHYPERTENSIVES AND HEART FAILURE DRUGS-VASODILATOR ANTIHYPERTENSIVES Risk of hyperglycaemia when diazoxide is co administered with thiazides Additive effect both drugs have a hyperglycaemic effect Monitor blood glucose closely, particularly with diabetes... 

AZOLES - ITRACONAZOLE ANTI HYPERTENSIVES AND HEART FAILURE DRUGS -VASODILATOR ANTIHYPERTENSIVES - bosentan Azole antifungals t bosentan levels Azoles inhibit CYP3A4 and CYP2C9 Monitor LFTs closely... 

Antihypertensive drugs may alter catecholamine concentrations (particularly those that induce a reflex increase in sympathetic activity, e.g. vasodilators). False-positive results in tests can then occur and in the past patients have undergone unnecessary operations. ... 

NSAIDs inhibited the effects of aU antihypertensive drug categories. However, in patients taking beta-block-ers and vasodilators, NSAIDs produced a greater increase in supine mean blood pressure than in patients taking diuretics, but only the pooled inhibitory effect of NSAIDs on the effects of beta-blockers achieved statistical significance. When the data were analysed by tjrpe of NS AID the meta-analysis showed that aU NSAIDs increased supine blood pressure, and that piroxicam, indometacin, and ibuprofen produced the most marked increases. However, only piroxicam had a statistically significant effect with respect to placebo. Aspirin,... 

Quinethazone and Metolazone (685) are used in medicine as diuretics <63AF660>. Another quinazoline, Prazosin (686) is a vasodilator which is used as an antihypertensive drug <77MI 602-01 >. 

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