Doses Of Urapidil Research Articles

Применение урапидила для коррекции артериальной гипертензии при хирургии катаракты

Purpose. Comparative analysis of clinical efficacy of urapidil and droperidol for relief of arterial hypertension (AH) during cataract surgery. Material and methods. The study included 30 patients who underwent relief of intraoperative hypertension with urapidil or droperidol in combination with sedation. According to method of treatment of hypertension, 3 groups of patients were distinguished: 1st group – 10 patients whom were injected only with urapidil, 2nd group – 10 patients whom were injected urapidil against the background of sedation; 3rd group – 10 patients whom received droperidol against the background of sedation. Results. We relieved intraoperative rise in blood pressure and avoided complications associated with it, in all 3 groups. Using of urapidil did not cause side effects from cardiovascular, respiratory and nervous systems. The dose of urapidil was reduced when used in conjunction with sedatives. Droperidol has been shown to be effective in patients with cognitive impairment with signs of arousal. Conclusion. The applied methods of relief of intraoperative AH were effective in all patients. Urapidil for correction of AH in outpatients is justified due to its effectiveness and safety. Droperidol for treatment of AH is preferable for patients with unstable psychoemotional status, agitation. Such patients should be monitored in hospital. Key words: urapidil, ebrantil, droperidol, intraoperative arterial hypertension, ophthalmosurgery.

Effects of stellate ganglion block on the circulation stability of lower extremity tourniquet and endotracheal intubation

Objective To examine the effect of ultrasound-guided stellate ganglion block (SGB) on the tourniquet reaction of the lower limbs. Methods A total of sixty patients undergoing unilateral knee replacement surgery under general anesthesia were divided into 2 groups (n=30): control group and group SGB. The age of patients was 18-75 years old with ASA gradeⅠ,Ⅱ. Before general anesthesia, 1% lidocaine (10 ml) was injected into the right deltoid muscle in control group, but in the right cervical stellate ganglion in group SGB. HR, SBP, BIS and drug doses were recorded at various time points: before induction of anesthesia (T0), before intubation (T1), 1 min after intubation (T2), before tourninquet inflated (T3), tourniquet inflatable 30 min (T4), tourniquet inflation 1 h (T5), tourniquet deflation(T6), tourniquet deflation 3 min (T7) and tourniquet deflation 30 min (T8) after discharge. Results Compared with control group, group SGB showed significantly lower SBP at T2, T5, T6 and T7 (P 0.05). There was no significant difference in the BIS, the doses of propofol, remifentanil, ephedrine and phenylephrine between the two groups, while the dose of urapidil in group SGB was significantly less than control group. Conclusions SGB can reduce the cardiovascular response to the tourniquet and maintain stable perioperative circulation. Key words: Stellate ganglion block; Tourniquet

Efficacy of different doses of urapidil in preventing pituitrin-induced cardiovascular responses in patients undergoing laparoscopic myomectomy

Objective To evaluate the efficacy of different dones of urapidil in preventing pituitrin-induced cardiovascular responses in patients undergoing laparoscopic myomectomy.Methods Sixty ASA Ⅰ or Ⅱ patients,aged 27-41 yr,weighing 55-65 kg,scheduled for elective laparoscopic myomectomy under general anesthesia,were randonly divided into 4 groups (n =15 each):control group (group C) and urapidil 0.3,0.5 and 0.8 mg/kg groups (groups U1-3).Urapidil 0.3,0.5 and 0.8 mg/kg were injected intravenously in U1-3 groups respectively,while normal saline 5 ml was given in group C.The mixture of pituitrin 6 U and normal saline 20 ml was injected into the site of hysteromyoma 5 min later.The operation was then started.BIS value was maintained at 45-55.The occurrence of cardiovascular responses was recorded.Results The incidences of cardiovascular responses were 100％,67％,40％ and 20％ in groups C and U1-3 respectively.The incidence of cardiovascular responses was significantly lower in groups U1-3 than in group C,and in groups U2.3 than in group U1 ( P ＜ 0.01 ).There was no significant difference in the incidence of cordiovascular responses between U2 and U3 groups (P ＞ 0.05).Conclusion Urapidil can prevent pituitrin-induced cardiovascular responses in patients undergoing laparoscopic myomectomy and the optimal dose is 0.5 mg/kg. Key words: Piperazines; Pituitary hormones, posterior; Laparoscopy; Leiomyoma; Gynecologic surgical procedures; Hemodynamics

Effect of three different doses of urapidil on blood glucose concentrations in the streptozotocin diabetic rat

Diabetes mellitus associated with hypertension often causes perioperative complications. The alpha1-adrenoceptor antagonist/5-hydroxytryptamine-1A receptor agonist urapidil is an approved drug used in hypertension and hypertensive emergencies. 5-Hydroxytryptamine-1A (5-HT1A) receptor agonists impair glucose metabolism. To evaluate a possible dose-dependent hyperglycaemic effect of urapidil due to its 5-HT1A receptor agonistic properties, the effect of three doses of urapidil on hyperglycaemia in the streptozotocin diabetic rat was investigated. Male Wistar-Kyoto rats were made diabetic by streptozotocin and randomly allocated to the following daily treatments for 7 days (n = 6 each): urapidil 6 mg kg(-1), urapidil 20 mg kg(-1), urapidil 60 mg kg(-1), insulin 4 IU kg(-1) subcutaneously. One diabetic group and one non-diabetic healthy group served as controls. Treatment for 7 days with urapidil 20 mg kg(-1) and urapidil 60 mg kg(-1) reduced mean glucose concentrations significantly (urapidil-20: 15.6 +/- 1.1 mmol L(-1), P = 0.023; urapidil-60: 15.8 +/- 0.8 mmol L(-1), P = 0.04) compared with diabetic controls (20.9 +/- 0.8 mmol L(-1)), whereas those after urapidil 6 mg kg(-1) were similar to diabetic controls. Insulin treatment normalized blood glucose concentrations. The alpha1-adrenoceptor antagonist/5-HT1A receptor agonist urapidil has no hyperglycaemic effect on experimental diabetes mellitus, even in high doses, despite its 5-HT1A receptor agonistic properties.

Effect of three different doses of urapidil on blood glucose concentrations in the streptozotocin diabetic rat

Effect of three different doses of urapidil on blood glucose concentrations in the streptozotocin diabetic rat

Influence of alpha 1-adrenoceptor blockade and/or 5-HT1A agonism on blood pressure and heart rate at rest and during exercise in hypertensive dogs.

1. Antihypertensive effects resulting from alpha 1-adrenoceptor blockade and stimulation of central nervous 5-HT1A receptors were compared with the effects arising from stimulation of 5-HT1A receptors alone during arterial hypertension. 2. Urapidil and 5-methyl-urapidil were less effective in decreasing arterial blood pressure than the lowest dose of the selective 5-HT1A receptor agonist, flesinoxan. After the higher dose of urapidil, a certain dampening of barareceptor reflex was found which was also seen with flesinoxan. 3. Flesinoxan was the only drug which did not reduce the exercise-induced increase in systolic arterial blood pressure. 4. Stimulation of 5-HT1A receptors alone, which is assumed to occur with flesinoxan, exerted antihypertensive activity only at low doses, without inducing reflex tachycardia at rest. 5. Only the combined effects of alpha 1-adrenoceptor blockade and 5-HT1A receptor stimulation, as assumed to occur with urapidil and 5-methyl-urapidil, lead to both a decrease in arterial blood pressure at rest and during exercise.

Involvement of 5-HT1A Receptors in Blood Pressure Reduction by 8-OH-DPAT and Urapidil in Cats

This study investigated the effects of (-)-pindolol, a putative 5-HT1A receptor antagonist, upon the central hypotensive action of the antihypertensive drug urapidil and of the purported 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) in cats. Chloralose/urethane-anesthetized cats were thoracotomized and artificially ventilated. Blood pressure was monitored in the iliac artery, and the drugs were injected into the vertebral artery. Urapidil (1-300 nmol/kg) or 8-OH-DPAT (0.01-1 nmol/kg) dose-dependently reduced blood pressure. (-)-Pindolol (30 and 100 nmol/kg) shifted the dose-response curves of both drugs significantly and in a similar manner to the right. Doses of urapidil of 30 nmol/kg or higher also reduced the elevation of blood pressure following the intravenous injection of the alpha 1-adrenoceptor agonist cirazoline whereas 8-OH-DPAT was ineffective. Yet, the hypotensive response to the directly acting vasodilator nitroglycerin remained unchanged after urapidil. The results support the hypothesis that the centrally mediated component of the antihypertensive action of urapidil is due to stimulation of 5-HT1A receptors in the brainstem. Peripheral alpha 1-adrenoceptor blockade comes into play with higher doses of the drug administered via the vertebral artery.

Clinical pharmacology of urapidil

Animal investigations suggest that the mechanism of the antihypertensive effect of urapidil may be complex. Suggestions have included an alpha 1-blocking action, a weak beta 1-blocking effect, an interaction with a serotonin receptor and a central depression of sympathetic tone. Peripheral alpha 1-blocking activity has been demonstrated in man, and a shift to the right in the dose-response curve to phenylephrine has been found after administration of urapidil, while responses to angiotensin are not affected. Evidence for beta 1-blocking activity is marginal, but urapidil does not inhibit the exercise-induced increase in the heart rate, and there is only some suggestion of a possible inhibition of isoprenaline-induced tachycardia. Possible central activity may be deduced from the observation that while lower single doses reduce blood pressure and increase the heart rate, with higher doses the hypotensive effect continues but the tachycardia no longer occurs. However, lower doses of urapidil lead to an increase in noradrenaline levels, while changes in renin are less constant, but there has been a report that a high dose reduced vanillylmandelic acid excretion. Urapidil reduces peripheral resistance along with arterial pressure, and cardiac output is increased. In spite of a reduced arterial pressure, renal blood flow is maintained, presumably due to dilation of renal vessels. Urapidil is well absorbed orally with a bioavailability of about 70% and a tmax at about 4 h after a sustained release capsule. It is metabolized in the liver with a t1/2 of 4.7 h. In conclusion there is evidence that urapidil is an alpha 1-blocking drug in man.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypotensive Effect of Urapidil: CNS Site and Relative Contribution

The purposes of our study were to determine the contribution of the CNS to the hypotensive effect of urapidil in the cat and the specific brain site of action of this agent. For the first purpose, urapidil was studied on preganglionic sympathetic nerve activity, arterial pressure, and heart rate. Three systemic bolus doses of urapidil were administered (0.22, 0.44, and 1.3 mg/kg). All three doses lowered arterial pressure, and the highest dose produced a significant decrease in sympathetic nerve discharge in five of six animals studied. The lower two doses had no significant effect on sympathetic activity, and none of the doses altered heart rate. These results suggest that a high i.v. dose of urapidil is required to evoke hypotension by an action in the central nervous system (CNS). For the second purpose, urapidil was applied bilaterally to the intermediate area of the ventral surface of the medulla in doses of 25 and 50 micrograms. These doses caused decreases in arterial pressure of -6.1 +/- 2.2 (p less than 0.05) and -21.0 +/- 5.9 (p less than 0.05) mm Hg, respectively, but no change in heart rate. In addition, respiratory stimulation also occurred with the higher dose as respiratory minute volume increased by 81 +/- 14 ml/min (p less than 0.05). The highest dose of urapidil had no effect on arterial pressure when applied to other chemosensitive areas of the ventral surface of the brain. Comparative studies with prazosin (10 micrograms applied bilaterally to the intermediate area) indicated no hypotensive effect of this alpha 1-adrenoceptor blocking agent.(ABSTRACT TRUNCATED AT 250 WORDS)