BackgroundThe pharmacology of single doses of acetylsalicylic acid (ASA) administered intravenously (250 or 500 mg) or orally (100, 300, or 500 mg) was evaluated in a randomized, placebo-controlled, crossover study.MethodsBlood and urine samples were collected before and up to 24 hours after administration of ASA in 22 healthy volunteers. Pharmacokinetic parameters and measurements of platelet aggregation were determined using validated techniques.ResultsA comparison between administration routes showed that the geometric mean dose-corrected peak concentrations (Cmax/D) and the geometric mean dose-corrected area under the curve (AUC0–∞/D) were higher following intravenous administration of ASA 500 mg compared with oral administration (estimated ratios were 11.23 and 2.03, respectively). Complete inhibition of platelet aggregation was achieved within 5 minutes with both intravenous ASA doses, reflecting a rapid onset of inhibition that was not observed with oral dosing. At 5 minutes after administration, the mean reduction in arachidonic acid-induced thromboxane B2 synthesis ex vivo was 99.3% with ASA 250 mg intravenously and 99.7% with ASA 500 mg intravenously. In exploratory analyses, thromboxane B2 synthesis was significantly lower after intravenous versus oral ASA 500 mg (P<0.0001) at each observed time point up to the first hour after administration. Concentrations of 6-keto-prostaglandin1α at 5 and 20 minutes after dosing were also significantly lower with ASA 500 mg intravenously than with ASA 500 mg orally.ConclusionThis study demonstrates that intravenous ASA provides more rapid and consistent platelet inhibition than oral ASA within the first hour after dosing.
This open-label, parallel-group, single-dose study assessed the safety and pharmacokinetics of cinaciguat, a novel soluble guanylate cyclase activator in clinical development for the treatment of acute decompensated heart failure, in individuals with mild, moderate, or severe renal impairment compared with individuals with normal renal function. Cinaciguat was administered as a 100 µg/h continuous infusion over 4 hours. Plasma concentrations were determined by high-performance liquid chromatography coupled with mass spectrometry. Renal function had only minor effects on the pharmacokinetics of cinaciguat. The apparent volume of distribution at steady state was slightly increased in individuals with renal impairment. The total body clearance from plasma showed a slight tendency to increase with progression of renal impairment, which can be explained by an increased hematocrit in individuals with renal impairment. No relevant influence was found on the terminal half-life. The fraction of cinaciguat unbound in plasma was very low (<1%) in all groups. Pharmacokinetic variability tended to be somewhat increased in individuals with renal impairment. Adverse events were mostly mild, and their incidence was similar in all groups. In conclusion, cinaciguat, a promising drug candidate for the treatment of acute decompensated heart failure, will not require dose adjustment based on renal function.
This paper discusses in a critical manner the spectrum of commercially available files -for in-house use -on pharmaceutical development products, which has been expanding rapidly over the past few years. Increasing degrees of sophistication in both the file contents and ways of manipulating the data are becoming more evident. A brief overview of competitor information files of this type, currently being used by PDR (Pharmaceutical Documentation Ring) member companies, is included in this appraisal.The strengths and weaknesses of some of these information resources of importance to pharmaceutical research and development, strategic planning, marketing and other functions within the industrial environment of the health care sector are outlined, using examples. A number of proposals are made for improving the coverage and content of the range of files under discussion, since optimal use of these resources can only be made if certain standards of quality control and indexing are met.
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