ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03895.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The prevalence of hypertension increases with age. Multiple physiologic factors are involved in the development of hypertension in the elderly. Alpha1‐adrenergic blocking agents lower blood pressure through a reduction in total peripheral resistance. Prazosin, terazosin, and doxazosin have been shown to be equally effective in reducing blood pressure in older persons. The bioavailability, terminal elimination half‐life, and volume of distribution of prazosin is increased in the elderly. Hybrid drugs, such as ketanserin, urapidil, and indoramin are also effective in lowering blood pressure. Ketanserin seems to have a greater effect on blood pressure reduction in persons older than 60 years of age. Alpha1‐adrenergic blockers may be used safely in patients with diabetes, asthma, and hyperlipi

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03896.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

After the old “Sale of Food and Drugs” Ordinance, Cap. 144 was repealed, the new Food and Drugs Act was enacted in 1971. This new Act has considerable flexibility and gives the Minister extensive authority to make Regulations (for carrying out the purposes and provisions of the Act). The Act controls the manufacture, importation, sale, advertising, labeling, packaging, and distribution of drug samples, and the testing of drugs. The Act also controls raw materials and finished products of drugs at the point of entry into the country, with a single agency coordinating both the inspection and analytical services. Developing countries could ensure the procurement of safe, good quality, and effective drugs and devices with the enactment of a similar Food and Drugs Act only. Rapid assessment of Drug Safety, Quality and Efficacy is done through Guyana's participation in the WHO Certification Scheme on the Quality of Pharmaceutical Products moving in International Commerce. This certification scheme is highly commendable especially to third‐world countries. The Food and Drug Regulations (1977) have several unique features for drug, cosmetic and device control and they allow for a system of centralized control with limited staff to enforce the legislation. In summary, enforcement of legislative control of imported pharmaceuticals and product evaluation can be considered strong points in the drug regulatory and review process in Guyana. A cautious attitude is observed so as to ensure efficacy, safety, and quality of drugs entering the market. This Drug Regulatory and Review Process is recommended for implementation by third‐world countries with outdated drug legi

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03897.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03898.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The pharmacokinetics of isoproterenol (ISO) in infants and children have never been reported. The authors studied ISO pharmacokinetics in two disparate groups of pediatric intensive care unit patients: postoperative cardiac patients (POC, n = 10), and reactive airway disease patients (RAD, n = 9). In all, 44 blood samples were taken at steady‐state from the 19 patients, whereas from 15 patients samples were also taken just before and after discontinuation of ISO infusion. There were 12 male and 7 female patients in the study, and their ages ranged from 2 days to 14 years. The average ISO dosing rate was 0.30 μg/kg/minute for the whole study population, ranging from 0.01 to 5.5 μg/kg/minute. The POC patients received a significantly lower dosing rate than the RAD patients (0.029 ± 0.002 vs 0.50 ± 0.21 μg/kg/minute, P<.0001); the average steady‐state plasma concentrations of ISO were also lower in the POC patients (1.3 ± 0.3 versus 13.9 ± 4.9 ng/mL, P<.0001). The steady‐state plasma concentration, normalized to a dosing rate of .05 ng/kg/minute, was 1.9 ± 0.3 ng/mL for all patients, and the clearance was 42.5 ± 5.0 mg/kg/minute. Postoperative cardiac patients had a significant higher normalized steady‐state plasma concentration and moderately significant lower clearance than did RAD patients (2.1 ± 0.3 versus 1.7 ± 0.4 ng/mL, P<.05 and 33.2 ± 4.9 versus 48.4 ± 7.3, P<.06, respectively). The average plasma half‐life of ISO was 4.2 ± 1.5 minutes, and the volume of distribution was 216 ± 57 mg/kg. This study suggests that the pharmacokinetics of ISO in children is highly variable and may vary with serum concentration. The apparent higher clearance of ISO in the RAD patients may be related to an improved perfusion status relative to the POC patients or to a possible influence of no

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03899.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The fatty acid composition of plasma triglycerides, phospholipids, and cholesterol esters have been studied during gemfibrozil (G)‐induced lipid‐lowering treatment in six patients with hypertriglyceridemia. Gemfibrozil caused significant plasma triglyceride reductions from 776 ± 573 to 226 ± 82 mg/dL (P<.001). Gemfibrozil therapy also caused significant changes in the plasma lipid fatty acid composition, mainly by increasing palmitoleic acid (16:1) in triglycerides (2.1–5.6%) and cholesterol esters (2.2–3.7%), concomitant with the significant decrease in the content of the linoleic acid (18:2) in phospholipids (20.1–16.0%) and triglycerides (18.0–15.2%). The ratio of unsaturated fatty acids (20:3 + 20:4/18:2) was increased in the phospholipid fraction. These findings support a G effect on the desaturation of fatty acids in patients with hypertriglyceridemia. Because fatty acid composition was significantly altered by G, those biologic systems dependent on the pattern of fatty acids may be modified in clinical i

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03900.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Angiotensin‐Converting enzyme (ACE) inhibitors have been designed to block the renin‐angiotensin system and can represent an effective therapeutic approach in those settings where such a system is active, such as myocardial infarction. In a randomized placebo‐controlled study, 10 patients with acute myocardial infarction allocated to treatment with increasing doses of zofenopril calcium and 10 patients allocated to placebo were studied in hospital, within 24 hours from symptoms, during 11 sampling periods to assess the time course of ACE inhibition and renin‐angiotensin‐aldosterone blockade. Zofenopril administration was followed by a dose‐dependent inhibition of in vitro ACE activity (7.5 mg, 65%; 15 mg, 89%; 30 mg, 94.5%) and a progressive increase in plasma active renin. Conversely, plasma aldosterone decreased during the first 3 days of treatment and then returned toward baseline values, as did blood pressure, despite a persistent inhibition of ACE. The present data suggest the existence of an interesting dissociation between the time‐course of ACE inhibition and that of blockade of the renin‐angiotensin system in patients with acute myocardial infarction. This discrepancy could arise from the combination of an only partial in vivo ACE inhibition and the compensatory increase in plasma renin that occurs during treatment with ACE inhibitors. A better understanding of this relationship would seem to be useful in addressing the correct use of ACE inhibitors in patients with acute my

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03901.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Nisoldipine is a new calcium‐channel blocker of the dihydropyridine subclass, with a chemical structure similar to nifedipine. It has been used in clinical trials to assess its efficacy and safety in patients with hypertension, angina pectoris, and congestive heart failure. Similar to other dihydropyridines, nisoldipine is a potent peripheral and coronary dilator. The most optimal dosage regimen has not been established in clinical trials. The drug appears to have a favorable side‐effect prof

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03902.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Enoxacin is a quinolone antibacterial agent currently being developed for oral and intravenous treatment of bacterial infections. Ten healthy subjects received a single 400‐mg intravenous dose of enoxacin alone, with 300 mg (four times daily) oral Cimetidine and with 150 mg (twice daily) oral ranitidine. Serial blood and urine samples were collected over a 48‐hour period. Plasma and urine enoxacin concentrations were determined using a validated high‐performance liquid chromatographic method. Mean enoxacin plasma concentrations were higher after administration of enoxacin with Cimetidine than those measured after enoxacin alone or enoxacin with ranitidine. Cimetidine coadministration reduced enoxacin renal clearance by 26% and systemic clearance by 20%, and resulted in a 30% increase in elimination half‐life. In contrast, concurrent ranitidine therapy did not significantly alter the pharmacokinetics of intravenous e

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03903.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The safety and pharmacokinetic properties of DQ‐2556, a new parenteral cephalosporin, were evaluated using healthy volunteers after 5‐minute intravenous infusion of doses of 250, 500, 1000, or 2000 mg and a 1‐hour infusion of 2000 mg, and an intramuscular dose of 500 mg. The half‐lives of DQ‐2556 ranged from 1.64 to 2.15 hours. The peak serum concentrations and area under the curve values were linearly correlated to the doses. The mean urinary recoveries were 80.0 to 85.5% of a dose within 24 hours. Salivary concentrations of the drug were low. There was no accumulation of DQ‐2556 after 9 administrations every 12 hours. DQ‐2556 was w

ISSN:0091-2700    

DOI:10.1002/j.1552-4604.1993.tb03904.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY