Drugs online research references
Br J Clin Pharmacol. 1986;21 Suppl 1:27S-31S.
Clinical pharmacological studies with doxazosin.
Elliott HL, Meredith PA, Vincent J, Reid JL.
The clinical pharmacology of doxazosin is reviewed from studies in normotensive young (21-39 years) and elderly (62-89 years) subjects following oral (2 mg) and intravenous (1 mg) administration. In young subjects the mean bioavailability was 65% and the mean terminal elimination half-lives were 9.5 and 10.5 h following acute intravenous and oral administration respectively. These parameters were similar in the elderly with bioavailability of 69% and half-lives of 8.8 and 11.9 h. The apparent volume of distribution and clearance were significantly higher in elderly (1.7 1 kg-1 and 140 ml min-1) than in young subjects (1.01 kg-1 and 83 ml min-1). In both groups blood pressure reductions were most marked in the standing position and the maximum effect did not occur until 5-6 h, even after intravenous administration. The blood pressure reduction produced by doxazosin was associated in the young with a significant increase in heart rate to 108 beats min-1 (placebo, 82 beats min-1) but this increase was significantly attenuated in the elderly at 91 beats min-1 (placebo, 77 beats min-1). Pressor response studies in the young subjects confirmed the alpha 1-adrenoceptor antagonist activity of doxazosin with significant rightward shifts of the dose-response curves for the selective alpha 1-adrenoceptor agonist phenylephrine. Using the technique of concentration-effect analysis, both the degree of alpha 1-adrenoceptor antagonism and the hypotensive effect can be correlated with the concentration of doxazosin in the 'effect compartment'.(ABSTRACT TRUNCATED AT 250 WORDS)
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2871854&dopt=Abstract
Br J Clin Pharmacol. 1986;21 Suppl 1:9S-17S.
The alpha 1-adrenoceptor antagonist profile of doxazosin: preclinical pharmacology.
Alabaster VA, Davey MJ.
The antihypertensive efficacy of the new alpha 1-adrenoceptor antagonist doxazosin is described, and its selectivity for alpha 1-adrenoceptors is reported from both in vivo and in vitro studies. Groups of beagle dogs with chronic perinephritic hypertension were given doxazosin orally, and systolic blood pressure was recorded indirectly from an exteriorized carotid loop. Dogs given doxazosin 0.5 mg kg-1 daily for 10 days showed consistent daily falls in systolic pressure in addition to a progressive reduction in daily pre-dose pressures. A clear indication of antihypertensive action in excess of 24 h post dose was evident. Heart rate changes were minimal. In pentobarbitone anaesthetized dogs pretreated with desimipramine, doxazosin 10-500 micrograms kg-1 i.v. reduced responses of the nictitating membrane to electrical stimulation of the vagosympathetic-depressor nerve trunk (an alpha 1-adrenoceptor response) but had no effect on the chronotropic response of the heart to electrical stimulation of the ansa subclavia. In contrast, the prejunctional alpha 2-adrenoceptor antagonist activity of yohimbine 10-100 micrograms kg-1 i.v. was manifest as a marked dose-related increase in both the heart rate and nictitating membrane responses. The lack of effect of doxazosin on postjunctional alpha 2-adrenoceptors in vivo was demonstrated in the anaesthetized cat. Doxazosin at 50 and 100 micrograms kg-1 i.v. inhibited pressor responses to injected phenylephrine (an alpha 1-adrenoceptor agonist) but had no effect on pressor responses to either alpha-methylnoradrenaline (an alpha 2-adrenoceptor agonist) or angiotensin II.(ABSTRACT TRUNCATED AT 250 WORDS)
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2871857&dopt=Abstract
Cardiology. 1986;73(3):164-74.
Clinical pharmacology and therapeutic role of prazosin and related alpha-adrenoceptor antagonists.
Reid JL, Vincent J.
Prazosin is a quinazoline derivative, which lowers blood pressure by selective alpha-1-receptor antagonism. It has been found that, for similar decreases in blood pressure, prazosin causes less reflex tachycardia than non-selective alpha blockers or direct vasodilators, and that it is as efficacious as other conventional antihypertensive agents (alpha-methyldopa, hydralazine, beta blockers, etc.) in controlling severe hypertension. Prazosin causes a dose-related decrease in blood pressure in humans; twice-daily dosing is sufficient for 24-hour blood pressure control. Prazosin in combination with other drugs has also been shown to control blood pressure effectively, and it has been associated with relatively few side effects. Other agents with selective alpha-1-receptor-blocking activity are under investigation: these include doxazosin, trimazosin, terazosin, and alfuzosin.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2872958&dopt=Abstract
online pharmacies ||
Hair Million herbal formula for hair loss and hair growth ||
Amoxicillin ||
Tramadol ||
Paxil ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Zithromax ||
online pharmacy ||
Antibiotics and prescription medications online literature ||
Antibiotics