Hypotensive response

Glonidine. Clonidine decreases blood pressure, heart rate, cardiac output, stroke volume, and total peripheral resistance. It activates central a2 adrenoceptors ia the brainstem vasomotor center and produces a prolonged hypotensive response. Clonidine, most efficaciously used concomitantly with a diuretic in long-term treatment, decreases renin and aldosterone secretion. 

Figures 2 and 3 illustrate the constant release of pilocarpiae over the seven day treatment period. An initial burst of dmg iato the eye is seen ia the first few hours. This is temporary and the system drops to the rated value ia approximately six hours. The total amount of dmg released ia this transitory period is less than that normally given ia pilocarpiae ophthalmic solutions. The ocular hypotensive effect of these devices is hiUy developed within 2 hours of placement ia the conjunctival sac, and the hypotensive response is maintained throughout the therapy. This system replaces the need for eyedrops apphed four times per day to control iatraocular pressure.

Cautiously administer the IV injection to avoid a possible hypotensive response. Initial arrhythmia control, under blood pressure and ECG monitoring, may usually be accomplished safely within 30 minutes by either of the 2 methods that follow ... 

Initial dose 1 mg at bedtime is the starting dose for all patients do not exceed as an initial dose. Closely monitor patients to minimize the risk of severe hypotensive response. 

High-risk patients Hypertensive patients at risk of excessive hypotension include those with the following concurrent conditions or characteristics Heart failure, hyponatremia, high-dose diuretic therapy, recent intensive diureses or increase in diuretic dose, renal dialysis, or severe volume or salt depletion of any etiology. Single doses of enalaprilat as low as 0.2 mg have produced excessive hypotension in normotensive patients with these diagnoses. Because of the potential for an extreme hypotensive response in these patients, initiate therapy under very close medical supervision. The... 

Thiazide diuretics are effective antihypertensive agents in black hypertensive patients and studies suggest that they cause a greater decrease in blood pressure in black patients than in whites. The better hypotensive response in black hypertensive patients is probably due to the fact that, in comparison with whites, more black patients have an expanded intracellular volume and low plasma renin activity. In developing countries, in which the majority of black people live, the cost of therapy is important. Thiazide diuretics are because of their low cost important baseline drugs in the treatment of hypertension. 

The hypotensive response to captopril is accompanied by a fall in plasma aldosterone and angiotensin II levels and an increase in plasma renin activity. Serum potassium levels are not affected unless potassium supplements or potassium-sparing diuretics are used concomitantly this can result in severe hyperkalemia. 

Prazosin [P] Increased hypotensive response to first dose of prazosin. 

The Hypotensive Response to A3 Receptor Ligands in the Rat Is Mast Cell Dependent... 

Salzmann R, Fozard JR (1994) The Haemodynamic basis of the hypotensive response to the putative adenosine A3 receptor agonist, N6-2-(4-amino-phenyl)ethyl adenosine (APNEA) in the rat. Drug Dev Res 31 270... 

Bums AT, Davies DR, McLaren AJ, Cerundolo L, Morris PJ, Fuggle SV (1998) Apoptosis in ischemia/reperfusion injury of human renal allografts. Transplantation 66(7) 872-876 Carruthers AM, Fozard JR (1993a) Adenosine A3 receptors mediate hypotension in the angiotensin II-supported circulation of the pithed rat. Br J Pharmacol 109(l) 3-5 Carruthers AM, Fozard JR (1993b) Effect of pertussis toxin treatment on the putative adenosine A i receptor-mediated hypotensive response in the rat. Eur J Pharmacol 250( 1) 185—188... 

When injected intravenously, kinins produce a rapid fall in blood pressure that is due to their arteriolar vasodilator action. The hypotensive response to bradykinin is of very brief duration. Intravenous infusions of the peptide fail to produce a sustained decrease in blood pressure prolonged hypotension can only be produced by progressively increasing the rate of infusion. The rapid reversibility of the hypotensive response to kinins is due primarily to reflex increases in heart rate, myocardial contractility, and cardiac output. In some species, bradykinin produces a biphasic change in blood pressure—an initial hypotensive response followed by an increase above the preinjection level. The increase in blood pressure may be due to a reflex activation of the sympathetic nervous system, but under some conditions, bradykinin can directly release catecholamines from the adrenal medulla and stimulate sympathetic ganglia. Bradykinin also increases blood pressure when injected into the central nervous system, but the physiologic significance of this effect is not clear, since it is unlikely that kinins cross the blood-brain barrier. 

May JA, McLaughlin MA, Sharif NA, Hellberg MR, Dean TR. Evaluation of the ocular hypotensive response of serotonin 5-HT1A and 5-HT2 receptor ligands in conscious ocular hypertensive Cynomolgus monkeys. J Pharmacol Exp Ther... 

When administered three times daily for 3 months, apraclonidine 0.5% has an ocular hypotensive effect comparable with that of timolol 0.5% administered twice daily. Age, race, and iris color do not seem to affect the ocular hypotensive response to apraclonidine. 

Apraclonidine 0.5% can be used for short-term therapy of patients on maximally tolerated medical therapy who require additional reductions in lOP Patients with primary or secondary glaucoma do not appear to differ in either the magnitude or duration of ocular hypotensive response, but patients with developmental or congenital glaucomas tend to respond less satisfectorily. 

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