The disposition and metabolism of captopril.
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Angiotensin-Converting Enzyme Inhibitors↗
Biomedical subjects
O H Drummer
Publications and source records attributed to O H Drummer.
Radioimmunoassay for immunoreactive [des-Leu10]-angiotensin I.
A specific radioimmunoassay for the angiotensin-derived peptide [des-Leu10]-angiotensin I (AI-dL) is described. Antisera obtained from rabbits injected with immunogen prepared by coupling bovine beta-thyroglobulin to the peptide with carbodiimide were specific to this peptide and did not recognise related angiotensin peptides such as AI, AII, AIII, nor did they recognise other peptides such as bradykinin, substance P, bombesin or dynorphin(1-8). Immunoreactive AI-dL was detected for the first time in the plasma of rats and humans following purification by HPLC at concentrations of 78 and 40 pg/ml, respectively. Concentrations of AI-dL are increased following chronic administration of captopril to rats.
Angiotensin I↗
Simultaneous HPLC gradient analysis of 15 benzodiazepines and selected metabolites in postmortem blood.
The simultaneous identification and quantitation of 15 benzodiazepines and selected metabolites in postmortem blood, serum, or liver homogenate is described. The assay involves extraction with diethylether, followed by an acid clean-up step of the ether. Chromatographic separation was achieved on a Nova-Pak phenyl 18 column using ultraviolet detection at 240 nm. A gradient HPLC system was developed to improve separation of nitro-reduction metabolites from the solvent front and endogenous peaks. The mobile phases consisted of a gradient from 15 to 28% acetonitrile in 40 mM potassium phosphate buffer. Within-run and day-to-day precision were generally 10-15%. The method described is sensitive and reproducible for the analysis of benzodiazepine concentrations in postmortem tissues.
Benzodiazepines↗
A class-independent drug screen in forensic toxicology using a photodiode array detector.
A class-independent drug screen, that is suitable for use in clinical and forensic toxicology and uses gradient-elution high-performance liquid chromatography and photodiode array detection, is presented. The assay is capable of detecting and identifying therapeutic and toxic amounts of barbiturates, anti-convulsants, diuretics, non-steroidal anti-inflammatory drugs, sulfonylurea anti-diabetic drugs, theophylline, and analgesic drugs. The assay has been successfully used to screen over 1000 postmortem blood specimens.
Chromatography, High Pressure Liquid↗
Capillary gas chromatographic drug screen for use in forensic toxicology.
A screening method is presented involving the use of capillary gas chromatography using a BP-5 column and nitrogen-phosphorous detection. This method is a quick yet reliable procedure for a large range of neutral and basic drugs and uses 1 mL or less of blood. Running standards that contain a number of commonly observed drugs with each batch of cases allows for more accurate tentative identifications of likely drugs in unknown cases and also provides a measure of quality assurance. This method is suitable for postmortem and clinical blood samples as well as plasma and serum.
Chromatography, Gas↗
Simultaneous determination of morphine and codeine in blood and bile using dual ultraviolet and fluorescence high-performance liquid chromatography.
The separation and identification of morphine and codeine from postmortem blood and bile was accomplished using a liquid-phase extraction method followed by reversed-phase high-performance liquid chromatography with combined UV and fluorescence detection. Identification of morphine and codeine was based on relative retention time matching with calibration standards, together with their fluorescence-to-UV response ratios. Linear calibration curves for morphine and codeine ranged from 0.10 to 3.0 mg/L for blood and 5.0 to 100 mg/L for bile. Morphine concentrations (in autopsy cases), where the intravenous use of heroin or morphine was suspected as the cause of death, were 0.10-0.89 mg/L (mean, 0.29 mg/L) for blood and 3.3-112 mg/L (mean, 38 mg/L) for bile. Codeine concentrations, where therapeutic use or overdosage of codeine occurred, were 0.06-6.4 mg/L (mean, 1.5 mg/L) in blood and 0.22-89 mg/L (mean, 24 mg/L) in bile. This method allowed simultaneous detection of morphine and codeine from blood and bile with little interference from extraneous peaks. The procedure described provides a selective, sensitive, accurate, and reliable method suitable for both clinical and forensic toxicology.
Bile↗
Pharmacokinetics and concentration--effect relationships of bevantolol (CI-775) in normal volunteers.
The pharmacokinetic handling of the beta 1 selective adrenoceptor blocking drug, bevantolol, was studied in 12 healthy volunteers. After intravenous (i.v.) administration of 50 mg of the drug, there was a biexponential decline in plasma levels with a terminal elimination half life (t1/2) of 1.9 h (range 1.4-2.3 h) and a total apparent volume of distribution at equilibrium of 62 L. After oral administration of the same dose, the bioavailability averaged 57% (range 26-98%) and peak plasma levels varied over a threefold range. On average, less than 1% of the dose was eliminated unchanged in the urine, indicating that the clearance of the drug was accounted for almost entirely by metabolism. Plasma levels after oral dosing with food showed an average 75-min delay in achievement of peak plasma levels and an average 14% increase in the extent of bioavailability of the drug. A positive correlation (r = 0.79) existed between the logarithm of the plasma bevantolol level and the percentage of reduction in postexercise heart rate. A plasma drug level of approximately 200 ng/ml produced a 10% reduction in postexercise heart rate. Pharmacological studies using guinea pig atrial and tracheal tissue demonstrated that the beta-blocking potency and beta-selectivity of bevantolol were intermediate between those of metoprolol and atenolol.
Adrenergic beta-Antagonists↗
Gas chromatographic measurement of plasma levels of sodium valproate: tentative therapeutic range of a new anticonvulsant in the treatment of refractory epileptics.
1. A precise and rapid gas chromatographic method for the measurement of plasma sodium valproate concentrations is presented. 2. The extraction is a single step procedure, and is reproducible and linear throughout the concentration range encountered. 3. Clinical evaluation of the drug is presented in eighteen epileptics on the basis of the percentage of days on which subjects had seizures before and after sodium valproate therapy. 4. A tentative therapeutic range for sodium valproate is presented on the basis of plasma levels and therapeutic effect.
Chromatography, Gas↗