ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Nicardipine is the first intravenously administered dihydropyridine calcium channel blocker. Its primary physiologic action includes vasodilatation with limited effects on the inotropic and dromotropic function of the myocardium. Several previous reports document its use in adult patients for pharmacologic control of blood pressure. The current report describes the use of nicardipine to control mean arterial pressure (MAP) in nine infants and children after cardiothoracic surgical procedures. The patients ranged in age from 6 days to 9 years (mean, 3.3 ± 4.1 years) and in weight from 4.1 to 49 kg (mean, 15.3 ± 14.4). The surgical procedures included aortic coarctation repair (three), repair of tetralogy of Fallot (two), arterial switch for transposition of the great vessels (two), pulmonary valvotomy (one), and aortic valvotomy (one). The target systolic blood pressure was 90 mm Hg in patients younger than 4 years of age and ≤110 mm Hg in patients 5 years of age or older. The nicardipine infusion was started at 5 &mgr;g/kg/min in all patients. The target blood pressure was achieved within 15 minutes in eight of nine patients. One patient required an initial infusion rate of 10 &mgr;g/kg/min to achieve the target blood pressure. The maintenance infusion rate varied from 2.5 to 5.5 mcg/k/min (mean 3.0 ± 1.1). The duration of the infusion varied from 30 to 42 hours (mean, 37.4 ± 4.2). In the nine patients, nicardipine was infused for a total of 337 hours. No adverse effects such as excessive hypotension were noted. Nicardipine is an effective agent for controlling MAP after cardiothoracic surgical procedures in infants and children.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

We investigated the effect of the oral binder–activated charcoal on the excretion of diethylcarbamazine. Six healthy volunteers were given 150 mg diethylcarbamazine with 350 mL water each. One and 2 weeks later, they received 150 mg diethylcarbamazine plus 7.5 and 15 g activated charcoal, respectively, in 350 mL water as a charcoal slurry. Urinary levels of diethylcarbamazine were measured spectrophotometrically from 1 to 72 hours after ingestion in three different periods. Treatment with activated charcoal led to 5.4% urinary recovery of diethylcarbamazine, decreased excretion rate, and a much lower plateau indicator of reduced absorption. Activated charcoal reduces the absorption and urinary excretion rate of diethylcarbamazine by adsorbing it in the gastrointestinal tract.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Systemic vasculitis is a predominant clinical symptom in Henoch-Schönlein purpura (HSP), and some studies suggested that decreased blood fibrinolytic activity, as well as blood platelets, is of importance in the development of cutaneous vasculitis. Although patients with HSP have normal blood coagulation, little is known about the fibrinolytic system. On the other hand, it is known that the focus of Σ-aminocaproic acid (EACA) activity in vivo is probably the blood platelet–vessel wall interaction or a vascular component alone. The aim of this study was, therefore, to investigate blood coagulation and fibrinolytic system as well as the effect of hydrocortisone (H) plus EACA therapy (Group I) on plasma antithrombin-III (AT-III), &agr;1-proteinase inhibitor (&agr;1-PI), &agr;2-antiplasmin (&agr;2-A), &agr;2-macroglobulin (&agr;2-M) activity, fibrinogen and plasminogen concentrations in plasma, euglobulin clot lysis time (ELT), and disappearance rate of cutaneous vasculitis in 14 children with HSP aged 7.6 ± 3.1 (SD) years. Ten patients (8.6 ± 2.5 years old) were treated with H alone (Group II), and 8 healthy, age-matched children served as controls. Plasma proteinase inhibitor activity was estimated with the kinetic method using Boehringer chromozyme tests before administration of H (9.2 ± 3.3 mg/kg/d, i.v.) plus EACA (140 ± 52 mg/kg/d, p.o.) for 5.93 ± 2.05 days, and 24 hours after the last dose of EACA, as well as before and after treatment with H alone (8.25 ± 1.74 mg/kg/24 h, i.v.) for 7.1 ± 1.2 days. It was found that patients with HSP had the initial fibrinogen and plasminogen plasma concentrations significantly increased compared with the controls (Group I: 3.93 ± 1.3 g/L and 124 ± 38%; Group II: 4.24 ± 0.89 g/L and 134 ± 42% vs. 2.96 ± 0.34 g/L, and 90 ± 14%, respectively). Also, there was a marked decrease of the initial plasma &agr;2-A activity in Group II compared with the controls (0.69 ± 0.29 vs. 0.94 ± 0.11 IU/mL, respectively, t = 2.33,P< .045). Both treatment regimens significantly improved fibrinolysis, which manifested as a shortening of ELT, but the mean values of this parameter remained within normal range. After treatment with H plus EACA, the skin lesions started to disappear significantly faster compared with the H alone regimen (2.28 ± 0.45 days vs. 4.12 ± 1.05, t = 4.41,P< .0023). In four of six patients receiving H plus EACA therapy, an approximately 20% decrease of systolic and diastolic arterial blood pressure lasting for 5 to 7 hours after administration of EACA was observed. These results may suggest that children with HSP have impaired plasma fibrinolytic activity and that an increased release of plasminogen activator inhibitor-1 (PAI-1) might be, at least in part, responsible for this phenomenon. Concomitant use of H (∼10 mg/kg/d) plus EACA (∼100 mg/kg/d) for a few days opens new therapeutic possibilities in some children with HSP.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Control of hyperphosphatemia in renal failure is often difficult to achieve. Although calcium-containing phosphate binders have become the preferred phosphate binders, many patients require the addition of an aluminum-containing phosphate binder (APB). Enhanced aluminum absorption has been noted when APBs are administered with citrate-containing products such as citrate/citric acid solution (CCA). Alternative phosphate binders such as calcium acetate may also increase aluminum absorption. This study investigated the effect of CCAs on aluminum absorption when aluminum antacids (APBs) were administered concurrently and 2 hours apart. The effects of the alternative alkalinizing agent sodium bicarbonate and the alternate phosphate binding agent calcium acetate on aluminum absorption were also studied. During five 2-day phases, ten normal volunteers randomly received three times daily with standardized meals aluminum hydroxide alone and concurrently with NaHCO3, calcium acetate, CCA, or with CCA 2 hours postprandially. Twenty-four hour urines were collected on the second day of each phase and aluminum excretion was determined using inductively coupled plasma emission spectroscopy. Urine aluminum excretion was statistically significantly (P< .005) elevated in subjects receiving Al(OH)3and CCA both with meals, 269.3 ± 146.3 &mgr;g/d, and 2 hours after meals, 303.3 ± 142.9 &mgr;g/d, compared with 79.2 ± 52.0 &mgr;g/d during treatment with Al(OH)3alone. Administration of CCA 2 hours after APB does not permit the safe use of these agents concurrently. Concomitant administration of sodium bicarbonate and calcium acetate with APBs appears to be safe, as aluminum absorption was not affected.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The purpose of this investigation was to evaluate the effects of dopamine on heart rate (HR), systolic blood pressure (SBP), aldosterone, plasma renin activity (PRA), bradykinin, prolactin, corticotropin (ACTH), urinary output (UO), and urinary sodium (UNa) stratified by race. Sixteen healthy age-and weight-matched Caucasian and African American male subjects participated in this single-blind, three-phase study. The three phases included the following treatments and assessments: (i) 90-minute infusion of D5W 100 mL/h and control piggyback (control period); (ii) 90-minute infusion D5W 100 mL/h and 3 &mgr;g/kg/min dopamine (dopamine phase); (iii) assessments repeated 24 hours after dopamine administration (washout period). Plasma was analyzed for dopamine concentrations. Dopamine significantly increased HR and SBP across the study population. In addition, UO and UNa increased, prolactin was reversibly depressed, bradykinin and ACTH were unchanged, and aldosterone significantly rebounded on washout. With regard to race differences, SBP significantly increased in African Americans compared with Caucasians, and UNa significantly increased in Caucasians compared with African Americans. In summary, 3 &mgr;g/kg/min dopamine produced significant renal, hormonal, and hemodynamic changes in healthy men. Selected effects varied by race.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

WHI-P131 is a novel dimethoxyquinazoline compound that is a potent inhibitor of Janus kinase-3- (JAK3)–dependent mast cell responses. In the present study, the authors investigated the anti-anaphylactic activity and pharmacokinetics of WHI-P131 in mice. After intraperitoneal (i.p.) administration of two consecutive bolus doses of 25 mg/kg injected 30 min apart at dose level of 25 mg/kg, WHI-P131 was rapidly absorbed with an observed Cmaxof 82.6 &mgr;M, which is higher than the target concentration of 30 &mgr;M, at which WHI-P131 abrogates mast cell responses in vitro and the time to reach the maximum plasma concentration (tmax) was 10.0±2.9 min. At a nontoxic 50 mg/kg dose level, WHI-P131 prevented compound 48/80-induced mast cell histamine release and fatal anaphylaxis in mice. Further development of WHI-P131 may provide the basis for new and effective treatment as well as prevention programs for mast cell mediated allergic reactions in clinical settings.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

A pharmacodynamic (Emax) model for optimizing warfarin initiation had previously been reported. This study assessed the validity of this model, adjusted further for age in both the initial cohort and another cohort distinct from that used for the formulation of the model. Thirty-one patients undergoing oral anticoagulation for mainly cardiac indications were recruited from Kuala Lumpur. Thirty-four patients undergoing oral anticoagulation for deep vein thrombosis were recruited from Cambridge. They were studied for their anticoagulant response to the initiation of warfarin. The former were intuitively dosed after a 2-day loading of 10 mg warfarin/d. The latter all were commenced on warfarin via a standard 4-day induction protocol of Fennerty et al that allows early estimation of the required maintenance dose. The actual maintenance doses in both cohorts were compared with their predicted doses on the initiation of therapy that was calculated both from this model and from the induction protocol of Fennerty et al. The third day's international normalized ratio and age combination was additive in terms of their influence on the maintenance dose. The predictive model in both cohorts returned similar results and explained at least two thirds of the interindividual variability in warfarin maintenance dose requirements, whereas the induction protocol of Fennerty et al explained only one third of this interindividual variability. Use of this model in the form of the included nomogram should be able to decrease both the occurrence of either under-or overanticoagulation as well as the time taken to initiate treatment and decide the correct maintenance dose during the initiation of oral anticoagulation with warfarin in hospitals. A prospective evaluation of the nomogram is recommended.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Nonsteroidal anti-inflammatory drugs have been a mainstay in the treatment of inflammatory diseases such as rheumatoid arthritis. However, these agents can result in severe and occasionally life-threatening adverse effects that can limit therapeutic benefit. Progress toward safer anti-inflammatory therapy was aided by the discovery that cyclooxygenase (COX) exists as two isozymes, COX-1 and COX-2. Both isozymes form prostaglandins that support physiologic functions; however, the formation of proinflammatory prostaglandins is catalyzed by COX-2. Inhibition of COX-2 accounts for the anti-inflammatory and analgesic action of NSAIDs; however, concurrent inhibition of COX-1 inhibits prostaglandin-dependent mechanisms such as gastroduodenal mucosal defense and platelet aggregation. This inhibition is the basis of the gastrointestinal toxicity and bleeding characteristic of these drugs. These findings led to the hypothesis that agents that selectively inhibit COX-2 would possess anti-inflammatory and analgesic action but would spare COX-1, thereby avoiding adverse effects in the gastrointestinal tract and platelets. Selective COX-2 inhibitors are now available. The novelty of these agents has raised questions in the medical community as to what constitutes selectivity for COX-2. This review outlines the criteria that must be met to characterize a compound as COX-2–specific. Clinical evidence of clear improvement in gastrointestinal tolerability and safety must be demonstrated in addition to complementary evidence of COX-2 selectivity obtained from enzyme, biochemical, and clinical pharmacology evaluations.

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1075-2765    

出版商:OVID    

年代:2001

数据来源: OVID