The clinical effect of prazosin, an alpha-1-receptor blocking agent, was studied in 31 patients with benign prostatic hypertrophy. The daily dose of 1.5-6 mg of prazosin was given for 2 weeks to 3 months. The efficacy was assessed by using uroflowmetry calculated from maximum flow rate, average flow rate and residual urine volume. The result revealed significant improvement of day time frequency, night time frequency (p<0.05) and maximum and average flow rate (p<0.05). It was suspected that prazosin was the valuable alpha-1-receptor blocker for benign prostatic hypertrophy and worth while to initiate medical treatment before undergoing any surgical intervention or when surgery is contraindicated.
Humans ; Prazosin* ; Prostatic Hyperplasia*

The therapeutic effects of prazosin hydrochloride alone and in combination with diuretic and/or beta-blocker in 41 patients with essential hypertension were evaluated. The results were as follows: 1) Of 28 patients treated with prazosin alone, 18(64.2%) achieved normalization of blood pressure and 7(25.0%) had good response of treatment. 2) Of 16 patients, with inadequate control on initial treatment, treated with prazosin in combination with diuretic and beta-blocker, 14(87.5%) achieved normalization of blood pressure. 3) After therapy with prazosin alone, the mean blood pressure reduced 25/16mmHg(p<0.05/p<0.01). 4) After addition of diuretic or beta-blocker in 6 patients receiving prazosin alone with inadequate response, the mean blood pressure reduced 31/13mmHg(p<0.01/p<0.01). 5) After addition of prazosin in 10 patients receiving diuretic alone or diuretic and beta-blocker but with inadequate control, the mean blood pressure reduced 32/14 mmHg(p<0.01/p<0.01). 6) The side effects were noted in 10 patients(25.0%). The most popular one was dizziness(17.5%), and the next was headache(10.0%).
Blood Pressure ; Humans ; Hypertension* ; Prazosin*

Prazosin, a selective alpha-1-adrenoreceptor blocker, was used in a double-blind fashion to evaluate its efficacy in 20 men with chronic nonbacterial prostatitis who have no improvement with conventional treatments for 4 weeks. When the drug was compared to placebo therapy, obstructive and irritative voiding sympment with conventional treatments for 4 weeks. When the drug was compared to placebo therapy, obstructive and irritative voiding symptoms were improved (p<0.05). No side effects were noted except one who had indigestion.
Dyspepsia ; Humans ; Male ; Prazosin* ; Prostatitis*

Three groups of patients with newely diagnosed hypertension, or with hypertension not optimally controlled by previous treatment, completed a comparative study on the effects of Dihydrochlorothiazide, propranolol, and prazosin on plasma lipids after three months therapy. The drugs showed equipotent antihypertensive effects(P<0.01). Dihydrochlorothiazide administration was associated with a significant elevation of total cholesterol(42%, P<0.05), and triglyceride(8.1%, P<0.01). Changes of HDL-C(5.1%), LDL-C(3.3%), and cholesterol ratio(-4.8%) were not significant. Propranolol administration was associated with significant elevation of total cholesterol(3.8%, P<0.05), triglyceride(14.5%, P<0.005), and LDL-C(5.6%, P<0.005). Reduction of HDL-C(-7.8%, P<0.05) and cholesterol ratio(-14.7%, p<0.005) was also statistically significant. Prazosin administration was associated with significant decrease in total cholesterol(-6.6%, P<0.005), triglycride(-9.6%, P<0.005), and LDL-C(-11.7%, P<0.005), and significant elevation of HDL-C(10.6%,P<0.005) and cholesterol ratio(24.2%, P<0.005) was noted.
Cholesterol ; Humans ; Hydrochlorothiazide* ; Hypertension* ; Plasma ; Prazosin* ; Propranolol*

The antihypertensive effect of Minizide(0.5mg prazosin hydrochloride and 0.25mg polythiazide per tablet)was evaluated in 30 patients with essential hypertension with a dosage of one tablet a day for four weeks. The results were as follows : 1) Of 30 patients treated with Minizide, 21 patients(70.0%) achieved normalization of blood pressure and 5 patients(16.7%) had good response. 2) Mean drop in systolic and diastolic pressure were 29.0mmHg and 15.9mmHg respectively in supine position(P<0.005). 3) Mean drop in systolic and diastolic pressure were 28.5mmHg and 16.2mmhg respectively in sitting position(P<0.005). 4) In 14 patients(46.7%) among 30 patients treated with Minizide adverse reactions developed. The most frequent one was postural dizziness(23.3%). 5) Most adverse reactions were transient and tolerable. However, in three patients(two patients with postural dizziness and one patient with dry mouth) the medication was stopped due to adverse reactions.
Blood Pressure ; Dizziness ; Humans ; Hypertension ; Polythiazide ; Prazosin

Ketamine, a dissociative anesthetic, produces an increase in heart rate and blood pressure, but the precise mechanism of the cardiovascular stimulating affects of ketamine is not understood clearly. Clonidine, an antihypertensive agent, is an alpha-2 agonist that appears to act primarily on the CNS, where it apparently produces a decrease in the sympathetic outflow from the brain. Prazosin is antihypertensive agent that appears to evert its vasodilator action through the blockade of postsynaptic alpha-1 receptors. In order to investigate the effects of clonidine and prazosin on the heart rate and blood pressure increased by ketamine, ketamine was administered intravenously following administration of clonidine or prazosin in conscious patients. The results were as follows : 1) Intravenous ketamine (2 mg/kg) produced significant increases in heart rate and blood pressure by as much as 25%. 2) Intravenous clonidine (1.25 ug/kg) produced a decrease in the heart rate by 5 beats per minute and decreased blood pressure significantly. 3) In the clonidine pretreated group (1.25 ug/kg, lV), intravenous ketamine (2 mg/kg/kg, lV) produced significant increases in the heart rate and blood pressure without attenuation with clonidine 4) In the prasosin pretreated group (2 mg/kg~70 kg, PO), ketamine (2 mg/kg, lV) produced increases the in heart rate and blood pressure without attenuation with prasosin. From the above results, it was inferred that the action site of the cardiovascular stimulating effect of ketamine isn't a postsynaptic alpha-1 receptor and is different from the action site of clonidine.
Blood Pressure* ; Brain ; Clonidine* ; Heart Rate* ; Heart* ; Humans ; Ketamine* ; Prazosin*

We evaluated 41 patients with symptomatic benign prostatic hypertrophy who were treated with prazosin alone more than 3 months. Among them, 21 patients( 51.2%) showed improvement of both symptom score and maximal flow rate. There was the similar effectiveness on the patients with acute urinary retention as on the patients without retention. The pretreated prostate volume and prostate specific antigen were not statistically different between the responders and nonresponders.After with drawl of the medication, almost all patients immediately complained of the symptoms worsened again. So, we concluded that the d-blocker can be used as a first-line therapy in selected patients with symptomatic benign prostatic hypertrophy with temporal effect.
Humans ; Prazosin* ; Prostate ; Prostate-Specific Antigen ; Prostatic Hyperplasia ; Urinary Retention

Sixteen patients with prostatodynia underwent clinical studies including urodynamic study, MMPI, and endoscopy. As a control group, another 19 patients with nonbacterial prostatitis and 16 normal man of 20-40 years of age also underwent urodynamic study. The most characteristic urodynamic findings in patients with prostatodynia was a significant increase in maximum urethral closing pressure as compared to control group (mean, 140.9 : 92.1 : 84.1 cmH20). In prostatodynia group, peak urinary flow rate was also significantly decreased as compared to the control group (mean, 12.0: 17.8 : 23.9cc / sec). 11 of 16 patients with prostatodynia was found to have functional outlet obstruction, probably at sympathetically innervated urethral sphincter. And they were treated with minipress and diazepam, of whom 7 showed significant improvement both symptomatically and urodynamically. On MMPI 7patients with prostatodynia showed significant underlying psychiatric disorders, and were treated by psychiatric treatment, of whom 4 showed significant clinical improvement. 2 patients with prostatodynia showed vermontanal pseudopolyp suggestive of prostatitis, were treated with long term TMF-SMX administration, and showed significant improvement. It is suggested that prostatodynia may develop from urethral sphincter overactivity and underlying psychiatric disorders, and that at least some cases with prostatodynia are in fact prostatitis. Uroflowmetry, urethral pressure profile, MMPI study and repeated EPS study may be of help in deciding the treatment plan of prostatodynia.
Diazepam ; Endoscopy ; Humans ; MMPI ; Prazosin ; Prostatitis ; Urethra ; Urodynamics*

The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Blood Pressure ; Inflation, Economic ; Intracranial Pressure* ; Piperoxan ; Prazosin ; Rabbits

The author attempted to clarify the nature of alpha-adrenoceptors in relation to the pressor response to the increased intracranial pressure(ICP) in urethane-anesthetized rabbits, using the epidural balloon method. 1) The blood pressure increased in parallel with the raised ICP which was made by gradual inflation of the balloon. 2) B-HT 920, an alpha2-agonist, which elicited depressor and bradycardiac responses in normal rabbits inhibited markedly the pressor response to the raised ICP. 3) Piperoxan, an alpha2-antagonist, potentiated the pressor response to the raised ICP. 4) Piperoxan antagonized the depressor and bradycardiac responses by B-HT 920 as well as the inhibitory effect of B-HT 920 on the pressor response to the raised ICP. 5) The pressor response to the raised ICP were not affected at all by prazosin, an alpha1-antagonist. 6) Neither the depressor and bradycardiac responses by B-HT 920 itself nor the inhibitory effect of B-HT 920 on the pressor response to the raised ICP were significantly affected by prazosin. It is inferred from these observations that the central alpha-adrenoceptors play an important role in producing the pressor response to the raised ICP and that the receptors involved here seems to be of alpha2-type.
Blood Pressure ; Inflation, Economic ; Intracranial Pressure* ; Piperoxan ; Prazosin ; Rabbits