1
|
Polvi H, Pirhonen J, Erkkola R, Kaila T, Iisalo E. Single Dose of Pindolol in Normotensive Pregnancy: The Lack of Changes in Hemodynamics in Spite of Effective Beta-Receptor Binding. Hypertens Pregnancy 2009. [DOI: 10.3109/10641959309079450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
2
|
Bott-Kanner G, Hirsch M, Friedman S, Boner G, Ovadia J, Merlob P, Mor N, Modan M, Galai N, Rosenfeld JB. Antihypertensive Therapy in the Management of Hypertension in Pregnancy - A Clinical Double-Blind Study of Pindolol. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10641959209031044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
3
|
Dyke TM, Sams RA, Hinchcliff KW. Exercise-training-induced alterations in hepatic function in mares. J Appl Physiol (1985) 1998; 85:1442-7. [PMID: 9760339 DOI: 10.1152/jappl.1998.85.4.1442] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effects of exercise training on hepatic function in horses were determined by studying the plasma clearance of antipyrine (20 mg/kg iv) in adult mares that either underwent treadmill training for 5 wk (n = 7) or remained in box stalls for the same time period (n = 6). Training consisted of treadmill exercise at 60% (12 min/day) and 90% (3 min/day) of pretraining maximal oxygen consumption (V(O2)max) for 6 days/wk for 5 wk. V(O2)max and velocity to obtain a blood lactate concentration of 4 mmol/l were significantly increased (from 129 to 149 ml x min-1 x kg-1 and from 5.6 to 6.1 m/s, respectively) as a result of training. The plasma clearance and volume of distribution of antipyrine increased significantly in the trained group (from 5.5 to 6.4 ml x min-1 x kg-1 and from 813 to 881 ml/kg, respectively) and decreased significantly in the untrained group. Elimination half-lives did not change as a result of training or box rest. Increases in plasma antipyrine clearance were indicative of an increase in hepatic metabolism of antipyrine. Increases in the volume of distribution of antipyrine suggest that total body water increases as a result of exercise training.
Collapse
Affiliation(s)
- T M Dyke
- Analytical Toxicology Laboratory and Exercise Physiology Laboratory, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210-1089, USA
| | | | | |
Collapse
|
4
|
Yang BB, Hounslow NJ, Sedman AJ, Forgue ST. Effects of atorvastatin, an HMG-CoA reductase inhibitor, on hepatic oxidative metabolism of antipyrine. J Clin Pharmacol 1996; 36:356-60. [PMID: 8728350 DOI: 10.1002/j.1552-4604.1996.tb04212.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Possible effects of multiple-dose administration of atorvastatin on the pharmacokinetics of single-dose antipyrine were evaluated in this drug-drug interaction study. Twelve healthy male volunteers received three 200-mg capsules of antipyrine on days 1 and 22, and two 40-mg atorvastatin tablets in the morning on days 8 through 23. Serial blood and urine samples were collected after administration of each antipyrine dose. Plasma was analyzed for antipyrine, and urine samples were analyzed for antipyrine, 4-hydroxyantipyrine, and norantipyrine by validated high-performance liquid chromatography with ultraviolet detection. Overall, antipyrine and atorvastatin doses were well tolerated in healthy volunteers. Mean antipyrine concentrations in plasma after administration of a single, oral dose of antipyrine during coadministration of multiple doses of atorvastatin were nearly superimposible on concentrations after administration of antipyrine alone. Individual and mean parameter values for plasma pharmacokinetics of antipyrine were similar in both treatment periods. Atorvastatin did not significantly alter the fraction of clearance of antipyrine in plasma that occurred by urinary excretion of 4-hydroxyantipyrine and norantipyrine. These results indicate that the recommended highest daily dose of atorvastatin has negligible effects on antipyrine pharmacokinetics and on oxidative pathways responsible for the metabolism of antipyrine.
Collapse
Affiliation(s)
- B B Yang
- Department of Pharmacokinetics/Drug Metabolism, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, Michigan 48105, USA
| | | | | | | |
Collapse
|
5
|
Groen K, Breimer DD. Antipyrine, theophylline, and hexobarbital as in vivo P450 probe drugs. Methods Enzymol 1996; 272:169-77. [PMID: 8791775 DOI: 10.1016/s0076-6879(96)72021-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- K Groen
- Department of Clinical Pharmacokinetics, Janssen Research Foundation, Beerse, Belgium
| | | |
Collapse
|
6
|
Velic I, Metzler M, Hege HG, Weymann J. Separation and identification of phase I and phase II [14C]antipyrine metabolites in rat and dog urine. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1995; 666:139-47. [PMID: 7655612 DOI: 10.1016/0378-4347(94)00552-g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A simple and accurate HPLC procedure was developed to quantify, in a single run, all phase I and phase II [14C]antipyrine metabolites that occur in rat and dog urine. All metabolites were subjected to thermospray-LC-MS and EI-MS in order to establish their structure. The rat metabolizes antipyrine to eight major metabolites, six of which are conjugated; 1.4% of the dose was excreted unchanged, 18.9% in a free form, 30.6% as sulfates and 21.1% as glucuronides. The dog metabolizes antipyrine to four metabolites, all as sulfate (61.0% of the dose) or glucuronide conjugates (16.2% of the dose).
Collapse
Affiliation(s)
- I Velic
- Environmental Toxicology and Food Chemistry, University of Kaiserslautern, Germany
| | | | | | | |
Collapse
|
7
|
St Peter JV, Braeckman RA, Granneman GR, Locke CS, Cavanaugh JH, Awni WM. The effect of zileuton on antipyrine and indocyanine green disposition. Clin Pharmacol Ther 1995; 57:299-308. [PMID: 7697947 DOI: 10.1016/0009-9236(95)90155-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of single and multiple oral doses of zileuton on the pharmacokinetics of antipyrine and indocyanine green were studied in 16 healthy, nonsmoking adult men by means of a double-blind, randomized, parallel placebo-controlled design. Indocyanine green disposition was not significantly altered by zileuton. Plasma antipyrine clearance declined by 20% (p < 0.0005) and 52% (p < 0.0005) after single and multiple dose zileuton exposure, respectively. Total urinary recovery of unchanged antipyrine and metabolites decreased with zileuton exposure. Selective declines from baseline of 16% (p = 0.007) and 20% (p = 0.003) after single-dose zileuton and 30% (p < 0.0005) and 43% (p < 0.0005) after multiple-dose zileuton were detected in recovery of 4-hydroxyantipyrine and 3-hydroxymethylantipyrine, respectively. Urinary recovery of the N-demethylantipyrine metabolite norantipyrine and percent of conjugation of 3-hydroxymethylantipyrine were unchanged by zileuton. In conclusion, zileuton therapy has no detectable effect on indocyanine green disposition but exerts marked effects on antipyrine plasma and urine metabolite disposition.
Collapse
Affiliation(s)
- J V St Peter
- Drug Evaluation Unit, Hennepin County Medical Center, Minneapolis, MN 55404-1249, USA
| | | | | | | | | | | |
Collapse
|
8
|
Gurley BJ, Zermatten S, Skelton D. Determination of antipyrine in human serum by direct injection restricted access media liquid chromatography. J Pharm Biomed Anal 1994; 12:1591-5. [PMID: 7696384 DOI: 10.1016/0731-7085(94)00101-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- B J Gurley
- Department of Pharmaceutics, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock 72205
| | | | | |
Collapse
|
9
|
Strolin Benedetti M, Dostert P. Induction and autoinduction properties of rifamycin derivatives: a review of animal and human studies. ENVIRONMENTAL HEALTH PERSPECTIVES 1994; 102 Suppl 9:101-5. [PMID: 7698069 PMCID: PMC1566786 DOI: 10.1289/ehp.94102s9101] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Animal studies have demonstrated that the mouse and rabbit are far more responsive to the inductive properties of rifamycin derivatives than the rat and guinea pig. The rat hepatic cytochrome P450 system seems to be resistant to the action of rifampicin unless very high doses are used. Mouse hepatic microsomal mixed-function oxidase activity is markedly increased by repeated dosing with rifampicin, whereas administration of rifabutin may be ineffective. In humans, both rifampicin and rifabutin are extensively metabolized and induce their own metabolism. The induced metabolic pathways remain essentially unknown. Under autoinduction conditions, the elimination half-life of rifampicin decreases, whereas that of rifabutin is not altered. Although the effects of repeated administration of rifampicin and rifabutin on the various forms of cytochrome P450 in humans have not been extensively examined, there is convincing evidence that the P4503A subfamily is induced by either drug, whereas the P4501A subfamily and P4502D6 do not appear to be affected by rifampicin. Limited reliable information is available concerning the induction of human glucuronyltransferase activities by rifampicin and rifabutin which, however, do not seem to influence zidovudine glucuronide formation in healthy subjects.
Collapse
Affiliation(s)
- M Strolin Benedetti
- Pharmacia-Farmitalia Carlo Erba, R&D/Pharmacokinetics and Metabolism, Milan, Italy
| | | |
Collapse
|
10
|
Abstract
Inter- and intraindividual variability in pharmacokinetics of most drugs is largely determined by variable liver function as described by parameters of hepatic blood flow and metabolic capacity. These parameters may be altered as a result of disease affecting the liver, genetic differences in metabolising enzymes, and various types of drug interactions, including enzyme induction, enzyme inhibition or down-regulation. With the now known large number of drug metabolising enzymes, their differential substrate specificity, and their differential induction or inhibition, each test substance of liver function should be used as a probe for its specific metabolising enzyme. Thus, the concept of model test-substances providing general information about liver function has severe limitations. To test the metabolic activity of several enzymes, either several test substances may be given (cocktail approach) or several metabolites of a single test substance may be analysed (metabolic fingerprint approach). The enzyme-specific analysis of liver function results in a preference for analysis of the metabolites rather than analysis of the clearance of the parent test substance. There are specific methods to quantify the activity of cytochrome P450 enzymes such as CYP1A2, CYP2C9, CYP2C19MEPH, CYP2D6, CYP2E1, and CYP3A, and phase II enzymes, such as glutathione S-transferases, glucuronyl-transferases or N-acetyltransferases, in vivo. Interactions based on competitive or noncompetitive inhibition should be analysed specifically for the cytochrome P450 enzyme involved. At least 5 different types of cytochrome P450 enzyme induction may result in major variability of hepatic function; this may be quantified by biochemical parameters, clearance methods, or highly enzyme-specific methods such as Western blot analysis or molecular biological techniques such as mRNA quantification in blood and tissues. Therapeutic drug monitoring is already implicitly used for quantification of the enzyme activities relevant for a specific drug. Selective impairment of hepatic enzymes due to gene mutations may have an effect on the pharmacokinetics of certain drugs similar to that caused by cirrhosis. Assessment of this heritable source of variability in liver function is possible by in vivo or ex vivo enzymological methods. For genetically polymorphic enzymes and carrier proteins involved in drug disposition, molecular genetic methods using a patient's blood sample may be used for classification of the individual into: (i) the impaired or poor metaboliser (homozygous deficient); (ii) the extensive (homozygous active) metaboliser group; and (iii) the moderately extensive metaboliser (heterozygous) group. For hepatic blood flow determinations, galactose or sorbitol given at relatively low doses may be much better indicators than the indocyanine green.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- J Brockmöller
- Institut für Klinische Pharmakologie, Universitätsklinikum Charité, Humboldt-Universität, Berlin, Germany
| | | |
Collapse
|
11
|
Monshouwer M, Witkamp RF, Pijpers A, Verheijden JH, van Miert AS. Dose-dependent pharmacokinetic interaction between antipyrine and paracetamol in vivo and in vitro when administered as a cocktail in pig. Xenobiotica 1994; 24:347-55. [PMID: 8059538 DOI: 10.3109/00498259409045898] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1. The pharmacokinetic interactions between paracetamol (PA) and antipyrine (AP) were studied in pigs in order to investigate the usefulness of this combination for the simultaneous assessment of oxidative and conjugative metabolism. 2. When both drugs were given at a dose of 5 mg/kg, AP plasma clearance was reduced from 2.22 to 0.96 lh-1 kg-1. PA clearance was not changed in comparison with control values. 3. At a dose of 2 mg/kg no pharmacokinetic interaction between the two drugs was observed. 4. The only oxidative AP metabolite found in urine was 4-hydroxyantipyrine (4-OHA). It accounted for 80% of the dose and, like PA, it was completely glucuronidated. 5. The glucuronidation of PA has been studied in vitro in pig liver microsomes. The apparent Km value for PA glucuronidation was 40 mM with a Vmax = 54 nmol min-1 mg protein-1. To determine if 4-OHA and PA competed for the same UDP-glucuronosyl-transferase, the effect of 4-OHA and AP on PA glucuronidation was studied. It appeared that 4-OHA was a competitive inhibitor with a Ki app = 0.07 microM, whereas AP had no effect. 5. Results suggest a dose-dependent interaction between AP and PA, which may be due to competition at the level of glucuronidation. Therefore, the usefulness of AP and PA in vivo in a cocktail for metabolism studies is limited.
Collapse
Affiliation(s)
- M Monshouwer
- Department of Veterinary Basic Sciences, University of Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
12
|
Palette C, Cordonnier P, Tillequin F, Koch M, Advenier C, Pays M. Isolation and purification of three glucuronides of antipyrine. Proposal for an original analytical method for quantitation of sulpho- and glucuroconjugated metabolites. Biomed Chromatogr 1994; 8:77-84. [PMID: 8044026 DOI: 10.1002/bmc.1130080207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The determination of the concentrations of antipyrine metabolites in biological fluids is hampered by the difficulty in obtaining pure conjugated compounds to be used as standards. Most authors have proposed determination of total forms by high performance liquid chromatography (HPLC) after deconjugation of these metabolites using chemical or enzymatic hydrolysis. Up to now there is no satisfactory hydrolysis method for the study of all antipyrine metabolites. The situation is further complicated by the fact that the deconjugated metabolites are highly unstable whichever technique is being used. Because of the lack of stability of all these molecules it has been necessary to isolate the glucuroconjugated compounds from urine. We describe a method which allows us to obtain highly purified glucuroconjugated metabolites of antipyrine. Sulphoconjugated compounds have been synthesized previously. We are thus able to propose a chromatographic procedure which allows us to determine simultaneously all stable phase I and phase II metabolites of antipyrine in biological fluids without any step of extraction. This analytical technique allows us to study the activity of the different isoenzymes implicated in the metabolism of antipyrine.
Collapse
Affiliation(s)
- C Palette
- Department of Biochemistry, Pharmacology and Toxicology, Centre Hospitalier de Versailles, Le Chesnay, France
| | | | | | | | | | | |
Collapse
|
13
|
Benedek IH, Davidson AF, Pieniaszek HJ. Enzyme induction by moricizine: time course and extent in healthy subjects. J Clin Pharmacol 1994; 34:167-75. [PMID: 8163717 DOI: 10.1002/j.1552-4604.1994.tb03982.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Moricizine.HCl, a novel phenothiazine derivative with oral antiarrhythmic activity, was examined for its potential to induce its own hepatic metabolism and to alter the pharmacokinetics of the test substrate, antipyrine, in 12 healthy male subjects. Antipyrine oral clearance increased from a starting value of .74 mL/minute/kg to .98 (+32%, P < .01) after 7 days of moricizine administration (250 mg every 8 hours) and to 1.15 mL/minute/kg after 14 days (+47%, P < .05); t1/2 was correspondingly reduced. Moricizine oral clearance increased from a baseline of 3.01 L/hour/kg to 3.62 (+20%, P < .05) after 6 days of oral moricizine and 4.66 (+51%, not significant) after 13 days. Moricizine t1/2 was marginally, but consistently, increased (+23%, P < .05) instead of decreased as one would expect because of enzyme induction, presumably due to a decrease in systemic bioavailability and its influence on the oral volume of distribution. In half of the subjects who discontinued moricizine after 7 days, antipyrine pharmacokinetic values returned to near baseline 7 days later. Although moricizine was able to induce its own hepatic metabolism and that of antipyrine after 6 or 7 days of continuous administration, the electrocardiographic properties of moricizine did not appear to be altered by continuous dosing.
Collapse
Affiliation(s)
- I H Benedek
- Clinical Pharmacology Group, Du Pont Merck Pharmaceutical Company, Stine-Haskell Research Center, Newark, Delaware 19714
| | | | | |
Collapse
|
14
|
Witkamp RF, Nijmeijer SM, Kolker HJ, Noordhoek J, van Miert AS. Effect of gonadal hormones on the plasma clearance and metabolite formation of antipyrine in the dwarf goat. J Vet Pharmacol Ther 1993; 16:164-73. [PMID: 8345566 DOI: 10.1111/j.1365-2885.1993.tb00160.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of gonadal hormones on the plasma elimination and urinary metabolite profile of antipyrine was studied in dwarf goats. Female goats were treated with testosterone and male goats were treated with 17 beta-oestradiol. Castrated males were treated with either testosterone or 17 beta-oestradiol. Antipyrine (25 mg/kg, i.v.) was given both before and after the hormonal treatments. The effects of the hormonal status on the plasma elimination of the parent compound were not consistent. This was possibly due to the fact that formation of the main metabolite of antipyrine in the goat, 4-hydroxy antipyrine (OHA), was not affected by sex or hormonal treatment. On the other hand, there were clear effects of hormonal status on urinary excretion of the three other metabolites. In females and castrated males testosterone suppressed the formation of norantipyrine (NORA), 3-hydroxymethylantipyrine (HMA) and 4,4'-dihydroxyantipyrine (DOHA). Intact males produced smaller amounts of these metabolites than females. It is concluded that distinct xenobiotic metabolizing pathways exist in the dwarf goat, which are influenced in their activity by gonadal hormones. This confirms previous findings in rats and mice. The possibility that sex hormones influence drug metabolism in food-producing animals could have consequences for veterinary therapeutics and public health. This study also demonstrates that, when using the antipyrine test for the assessment of hepatic drug metabolism, it is very important to include the determination of metabolites.
Collapse
Affiliation(s)
- R F Witkamp
- Department of Veterinary Basic Sciences, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
15
|
Palette C, Dubor F, Rovei V, Advenier C. Determination of antipyrine sulphoconjugates in isolated cultured rat hepatocytes. Xenobiotica 1993; 23:181-91. [PMID: 8498081 DOI: 10.3109/00498259309059373] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. An analytical method for the simultaneous determination of three major metabolites of antipyrine, namely, 3-hydroxymethylantipyrine (phase I), 4-hydroxyantipyrine sulphoconjugate (phase II) and norantipyrine sulphoconjugate (phase II) in cultured rat hepatocytes has been developed and applied to the study of induction or inhibition of these metabolic pathways following pretreatment of rats with several inducers or inhibitors. 2. Phenobarbital was the most effective inducer of the three pathways studied, particularly the formation of 4-hydroxyantipyrine sulphoconjugate; 3-methyl-cholanthrene (MC) increased the formation of the two sulphoconjugates, but decreased the formation of 3-hydroxymethylantipyrine. 3. Rifampicin inhibits antipyrine metabolism in rat. The three metabolic pathways studied were decreased by 30%. 4. SKF 525A markedly inhibited the three metabolic pathways; piperonyl butoxide and omeprazole decreased the three pathways but to a lesser extent. Cimetidine decreased the two sulphoconjugates pathways, but did not affect 3-hydroxymethylantipyrine formation.
Collapse
Affiliation(s)
- C Palette
- Department of Biochemistry, Pharmacology and Toxicology, A. Mignot Hospital, Le Chesnay, France
| | | | | | | |
Collapse
|
16
|
Natsuhori M, Witkamp RF, Van 't Klooster GA, Van Miert AS. Metabolism of antipyrine and sulphadimidine in dwarf goats: effects of the enzyme-inducing agents phenobarbital, troleandomycin and rifampicin. Xenobiotica 1992; 22:1243-50. [PMID: 1492417 DOI: 10.3109/00498259209053153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. Antipyrine (AP) and sulphadimidine (SDD) plasma elimination and metabolite formation were studied in dwarf goats before and after treatment with phenobarbital (PB), triacetyloleandomycin (TAO), and rifampicin (RIF). 2. PB treatment significantly increased AP plasma clearance in both male and female goats. With SDD, only male goats were studied, which showed a significant increase of SDD plasma clearance following PB treatment. 3. After PB treatment, partial clearance values of four AP metabolites, 3-hydroxymethylantipyrine (HMA), norantipyrine (NORA), 4-hydroxyantipyrine (OHA) and 4,4'-dihydroxyantipyrine (DOHA), were significantly increased. This induction effect was different for the individual metabolites and also showed sex-dependency. 4. In PB-induced male goats the formation of the hydroxylated SDD metabolites, 6-hydroxymethyl-SDD and 5-hydroxy-SDD, was significantly increased. 5. After TAO treatment, female goats showed a slightly reduced AP plasma clearance and a decreased partial clearance of two AP metabolites, HMA and DOHA. There was no effect on SDD plasma elimination or metabolite excretion. 6. In male goats, RIF had no effect on plasma elimination of AP and SDD. With SDD, it decreased the urinary excretion of the unchanged drug and its N4-acetylated metabolite. 7. Induction/inhibition studies of drug metabolism in food-producing animal species are desirable to gain more insight into the regulation of enzymes involved in the metabolism of xenobiotics.
Collapse
Affiliation(s)
- M Natsuhori
- Department of Veterinary Basic Sciences, University of Utrecht, The Netherlands
| | | | | | | |
Collapse
|
17
|
Sarkar MA, March C, Karnes HT. Solid phase extraction and simultaneous high performance liquid chromatographic determination of antipyrine and its major metabolites in urine. Biomed Chromatogr 1992; 6:300-4. [PMID: 1286289 DOI: 10.1002/bmc.1130060611] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A reversed phase gradient high performance liquid chromatographic method utilizing solid phase extraction has been described for the simultaneous determination of antipyrine (AP), 4-hydroxyantipyrine (4-OHAP), norantipyrine (NorAP) and 3-hydroxymethylantipyrine (3-OHMAP) in human urine after hydrolysis with beta-glucuronidase. The C-18 sorbent cartridges were conditioned and urine samples were applied, washed with 1 x 4 mL of phosphate buffer and eluted with 3 x 100 microL of 20% v/v of acetonitrile in methylene chloride. The eluent was evaporated to dryness, reconstituted in 100 microL phosphate buffer and injected. The calibration ranges were 2.0-250 micrograms/mL (AP), 2.5-250 micrograms/mL (NorAP), 2.0-250 micrograms/mL (3-OHMAP) and 5.0-500 micrograms/mL (4-OHAP) with regression coefficients of 0.998 or greater. Specificity was indicated by the absence of interferences in chromatogram of blank urine from normal as well as cirrhotic patients. The average recovery was 86.7% for AP, 90.5% for NorAP, 85.2% for 4-OHAP and 74.2% for 3-OHMAP. The within-assay precision as indicated by the reproducibility of the assayed spiked urine was less than 9% in all cases and the between-assay precision was less than 12%. The method was applied to studies on antipyrine metabolism in stable cirrhotic patients. Following administration of a single oral dose of about 1000 mg to nine stable cirrhotic patients and eight age-matched healthy volunteers, the cumulative account excreted in the urine up to 48 h for AP and the three metabolites was comparable to other literature reports.
Collapse
Affiliation(s)
- M A Sarkar
- West Virginia University, School of Pharmacy, Department of Basic Pharmaceutical Sciences, Morgantown 26506
| | | | | |
Collapse
|
18
|
Borcherding SM, Bastian TL, Self TH, Abou-Shala N, LeDuc BW, Lalonde RL. Two- and four-day rifampin chemoprophylaxis regimens induce oxidative metabolism. Antimicrob Agents Chemother 1992; 36:1553-8. [PMID: 1510454 PMCID: PMC191619 DOI: 10.1128/aac.36.7.1553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The effects of two short-term chemoprophylaxis regimens of rifampin (2 or 4 days) on oxidative metabolism were investigated in 14 healthy subjects. Seven subjects received 600 mg of rifampin twice daily on study days 6 and 7 (group A), and seven subjects received 600 mg of rifampin once daily on days 4, 5, 6, and 7 (group B). Antipyrine (18 mg/kg of body weight) was administered orally on days 1, 8, and 15. Short-term rifampin regimens increased oral clearance of antipyrine in both groups compared with the baseline value (P less than 0.05), and group B displayed a larger percent increase over the baseline value than group A did (70.5 +/- 14.3 versus 33.1 +/- 18.1; P less than 0.05). The partial metabolic clearance (CLM) of antipyrine to 3-hydroxymethylantipyrine (HMA) on day 8 increased 71 and 108% for regimens A and B, respectively (P less than 0.05 for both). The corresponding increases in CLM to norantipyrine (NORA) were 57 and 98% (P less than 0.05 for both). CLM to 4-hydroxyantipyrine (OHA) on day 8 increased 64% for regimen A (P = 0.08) and 97% for regimen B (P less than 0.05) compared with the baseline. Although CLM to HMA and OHA on day 15 remained greater than 50% over the baseline with both regimens, CLM to NORA on day 15 was less than 25% over the baseline with both regimens. Thus, both short-term rifampin chemoprophylaxis regimens increased antipyrine clearance for at least 1 week. The increase tended to be higher with the 4-day regimen. The pattern observed for the CLMS suggests that more than one P-450 enzyme is affected.
Collapse
Affiliation(s)
- S M Borcherding
- Department of Clinical Pharmacy, University of Tennessee, Memphis 38136
| | | | | | | | | | | |
Collapse
|
19
|
St Peter JV, Abul-Hajj Y, Awni WM. The pharmacokinetics of antipyrine and three of its metabolites in the rabbit: intravenous administration of pure metabolites. Pharm Res 1991; 8:1470-6. [PMID: 1808608 DOI: 10.1023/a:1015830013451] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Antipyrine (AP) is a commonly used probe of oxidative metabolism. Indirect evidence demonstrates formation rate limited disposition of its metabolites. Kinetic studies using antipyrine and its major metabolites 3-hydroxymethylantipyrine (HMA), norantipyrine (NORA), and 4-hydroxyantipyrine (OHA) were completed to investigate the metabolic fate of preformed antipyrine metabolite and to demonstrate directly formation rate-limited metabolite disposition in vivo. Bolus injections of antipyrine and preformed metabolites (40-50 mg/kg) were administered to male, New Zealand white rabbits. Plasma and urine were analyzed using HPLC. These studies demonstrate that HMA, NORA, and OHA are formation rate limited in the rabbit. NORA appears to undergo further extensive oxidative and conjugative metabolism. Unknown additional peaks were detected in urine after NORA dosing but not after HMA or OHA administration. Mass spectroscopy of the unknown HPLC eluents identified potential structures of these NORA metabolites.
Collapse
Affiliation(s)
- J V St Peter
- Department of Medicine, Hennepin County Medical Center, Minneapolis 55415
| | | | | |
Collapse
|
20
|
Witkamp RF, Lohuis JA, Nijmeijer SM, Kolker HJ, Noordhoek J, van Miert AS. Species- and sex-related differences in the plasma clearance and metabolite formation of antipyrine. A comparative study in four animal species: cattle, goat, rat and rabbit. Xenobiotica 1991; 21:1483-92. [PMID: 1763522 DOI: 10.3109/00498259109044398] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The plasma disposition of antipyrine, and its urinary metabolite pattern, were studied in both sexes of four animal species: rat, dwarf goat, rabbit and cattle. 2. No sex differences in plasma elimination of antipyrine were found in rabbit and goat; however, in rat and cattle the effect of sex was marked. As expected, male rat showed a higher plasma clearance value than female. In contrast bulls showed a significantly lower clearance value than cows. 3. Metabolite patterns varied widely from one species to another. The major urinary metabolite in rabbit and the two ruminant species was 4-hydroxy-antipyrine (OHA), whereas in rat 3-hydroxymethylantipyrine (HMA) was quantitatively the most important metabolite. 4. HMA was excreted in the 24 h urine in larger amounts by male rats than by females. Metabolism of antipyrine to HMA was also sexually different in the dwarf goat, but in this species females were more active than males. The effect of sex on the metabolite pattern in cattle was marked. 5. It is concluded that in ruminants there may be xenobiotic metabolic pathways which are under hormonal control, just as there are in rats and mice. If hormones influence drug metabolism in food-producing animals, residue levels of xenobiotics or their metabolites in food from animal origin may differ with the sex of the animal, or may be altered after treatment with anabolic hormones.
Collapse
Affiliation(s)
- R F Witkamp
- Department of Veterinary Basic Sciences, University of Utrecht, The Netherlands
| | | | | | | | | | | |
Collapse
|
21
|
Park YH, Hudson JE, Barker RC, York BM, Brazzell RK. Metabolism of the aldose reductase inhibitor ALO1567 in man. Br J Clin Pharmacol 1991; 32:221-7. [PMID: 1931471 PMCID: PMC1368447 DOI: 10.1111/j.1365-2125.1991.tb03885.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
1. The metabolism of the aldose reductase inhibitor, ALO1567, was studied in man. The major biotransformation pathway was aromatic hydroxylation followed by glucuronide conjugation. 2. Hydroxylation occurred at several positions on the fluorene ring. The major metabolite was identified as the 7-hydroxy analogue of ALO1567 and three minor metabolites were characterized as positional isomers of the 7-hydroxy metabolite. 3. Oxidative defluorination and metabolism on the hydantoin ring were also indicated as minor pathways. 4. The capacity of normal subjects to oxidize ALO1567 was indicated by the urinary ratio of the parent drug to the 7-hydroxy metabolite after daily oral administration of 100 mg and 200 mg of ALO1567. Most subjects having higher ALO1567 plasma concentrations showed higher ratios.
Collapse
Affiliation(s)
- Y H Park
- Research and Development Alcon Laboratories, Inc., Forth Worth, Texas 76134
| | | | | | | | | |
Collapse
|
22
|
De Boer A, Stiekema JC, Danhof M, Breimer DD. The influence of Org 10172, a low molecular weight heparinoid, on antipyrine metabolism and the effect of enzyme induction on the response to Org 10172. Br J Clin Pharmacol 1991; 32:23-9. [PMID: 1716140 PMCID: PMC1368488 DOI: 10.1111/j.1365-2125.1991.tb05608.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
1. We have investigated the effect of repeated s.c. Org 10172 (a low molecular weight heparinoid; Lomoparan) treatment (1000 anti-Xa units twice daily for 5 days) on antipyrine (500 mg orally) metabolism, and the effect of enzyme induction by pentobarbitone (100 mg for 12 days) on the pharmacokinetics and pharmacodynamics of Org 10172 following an intravenous bolus injection of 3250 anti-Xa units. 2. Org 10172 treatment caused a small increase in the formation rates of all antipyrine metabolites (P less than 0.05), while the overall kinetics of antipyrine did not change significantly. 3. Oxidative enzyme induction by pentobarbitone, as demonstrated by an increased clearance of antipyrine, was associated with an increase in the area under the anti-thrombin activity vs time curve (P less than 0.05). No influence was seen on the kinetics of plasma anti-Xa and thrombin generation inhibiting (TGI) activity. 4. The pharmacodynamics of Org 10172, as determined by clotting tests, was not influenced by enzyme induction. 5. The clinical relevance of these observations is likely to be limited.
Collapse
Affiliation(s)
- A De Boer
- Center for Bio-Pharmaceutical Sciences, University of Leiden, The Netherlands
| | | | | | | |
Collapse
|
23
|
Kaka JS. Concurrent bromosulphophthalein and antipyrine administration to assess liver blood flow and hepatic enzymes in rats. Food Chem Toxicol 1991; 29:419-23. [PMID: 1874471 DOI: 10.1016/0278-6915(91)90083-j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This study investigated the feasibility of using concurrent iv administration of antipyrine (15 mg/kg body weight) and bromosulphophthalein (BSP; 25 mg/kg) in the rat. Antipyrine is used as an index of hepatic drug metabolism and BSP is used to assess hepatic blood flow. Plasma concentrations of BSP were described using biexponential phases, while antipyrine plasma concentrations were monoexponential. No significant difference was observed between antipyrine pharmacokinetic parameters in concurrent BSP rats when compared with controls. There was also no significant difference between BSP pharmacokinetic parameters in concurrent antipyrine rats when compared with controls, except in the alpha value (P less than 0.05). This indicates that BSP distribution may be affected by concurrent antipyrine administration. Therefore, simultaneous administration of both substrates is not acceptable to study hepatic blood flow. Another iv combination dose (25 mg BSP/kg body weight, followed by 15 mg antipyrine/kg 0.5 hr later) and a dose of 15 mg antipyrine/kg body weight only was administered to rats pretreated with phenobarbital (90 mg/kg body weight) for 6 days. Pharmacokinetic parameters of BSP, beta, k21, k23 and plasma clearance, in the pretreated rats were significantly different from non-pretreated rats. No significant difference was observed in the pharmacokinetic parameters of antipyrine between the combination dose and antipyrine dose in the phenobarbital-pretreated rats. The half-lives of antipyrine in both pretreated groups decreased approximately by 70%, while the clearance increased four times compared with controls. The volume of distribution in these animals did not change as a result of phenobarbital pretreatment. This suggests that a 25 mg BSP/kg body weight dose followed by 15 mg antipyrine/kg 0.5 hr later may be a feasible approach to study liver blood flow, as well as hepatic efficiency in rats.
Collapse
Affiliation(s)
- J S Kaka
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| |
Collapse
|
24
|
Horsmans Y, Desager JP, Pauwels S, Harvengt C. Lack of effect by nifedipine on hepatic mixed function oxidase in man. Fundam Clin Pharmacol 1991; 5:193-201. [PMID: 1937348 DOI: 10.1111/j.1472-8206.1991.tb00711.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nifedipine (NF), a calcium channel blocker, is often prescribed in association with other drugs. Therefore, it was interesting to know whether or not, nifedipine, which is metabolized by the cytochrome P-450NF, was able to induce or to inhibit in vivo the activity of the hepatic mixed function oxidase system. The study was conducted in ten young healthy male volunteers receiving 20 mg NF slow release bid for 15 days. Due to the small number of subjects, comparison of the NF pharmacokinetics at dose 1 and 26 failed to show a bimodality in the frequency distribution of its area under the plasma concentration-time curve (AUC 274.5 to 317.1 ng ml-1 h, NS). Hepatic microsomal autoinduction (t1/2 2.87 to 3.06 h, NS) was not found. No statistically significant effect was seen on the aminopyrine breath test and on the debrisoquine metabolic molar ratio performed before and at the end of the treatment. Unlike what has been suggested by in vitro studies, NF treatment did not modify significantly the urinary excretion of 6 beta-hydroxycortisol (318 to 265 micrograms/d, NS). After the last dose, the total oral clearance of NF was highly correlated with the metabolic clearance to 4-hydroxyantipyrine (r = 0.88; P = 0.005) but the other parameters of antipyrine biotransformation remained unchanged. We conclude that repeated nifedipine oral intake does not modify enzymatic activities of hepatic P-450 cytochromes involved in the biotransformation of antipyrine, aminopyrine, debrisoquine and cortisol.
Collapse
Affiliation(s)
- Y Horsmans
- Université Catholique de Louvain, Laboratoire de Pharmacothérapie, Brussels, Belgium
| | | | | | | |
Collapse
|
25
|
Palette C, Cordonnier P, Naline E, Advenier C, Pays M. High-performance liquid chromatographic method for the determination of the three main oxidative and 3-carboxylic antipyrine metabolites in human urine. JOURNAL OF CHROMATOGRAPHY 1991; 563:103-13. [PMID: 2061375 DOI: 10.1016/0378-4347(91)80281-g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The oxidative metabolism of xenobiotics is usually explored using the antipyrine test, which consists of determining the production clearances and urinary percentages of three major antipyrine metabolites 4-hydroxyantipyrine, norantipyrine and 3-hydroxymethylantipyrine. The total forms of these compounds are generally determined by high-performance liquid chromatography (HPLC). However, the 3-carboxylic acid metabolite (3-carboxyantipyrine), which is the ultimate oxidation form in the 3-hydroxylation pathway, should also be taken into account, but so far its determination by HPLC has not been reported. A simple and accurate HPLC method has now been developed to determine the three major metabolites plus 3-carboxyantipyrine. In this method, all compounds are extracted in an aprotic non-polar solvent, at pH 3.5 for the major metabolites and unchanged antipyrine, then at pH 0.9 for 3-carboxyantipyrine. Total forms are evaluated after enzymatic hydrolysis. Throughout the procedure, attention is paid to the relative instability of norantipyrine and 4-hydroxyantipyrine. Recovery, accuracy and precision are discussed. The method has been applied to the determination of relative amounts (percentage of the dose administered) excreted in the urine of ten adult subjects 48 h after ingestion of antipyrine (600 mg). The proportion of 3-carboxyantipyrine excreted was 4.5 +/- 0.2%, which is in agreement with published values obtained by gas chromatography. The excretion rates of the major metabolites also were similar to those reported in the literature, thereby confirming that the reported method is valid. 3-Carboxyantipyrine is totally excreted as the free form and norantipyrine almost completely as glucuroconjugate.
Collapse
Affiliation(s)
- C Palette
- Département de Biochimie, de Pharmacologie et de Toxicologie, Centre Hospitalier de Versailles, Le Chesnay, France
| | | | | | | | | |
Collapse
|
26
|
Pini LA, Ferretti C, Trenti T, Ferrari A, Sternieri E. Effects of long-term treatment with naltrexone on hepatic enzyme activity. DRUG METABOLISM AND DRUG INTERACTIONS 1991; 9:161-74. [PMID: 1686854 DOI: 10.1515/dmdi.1991.9.2.161] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The influence of naltrexone on liver function in heroin addicts was studied, with respect to the metabolizing function by using the antipyrine clearance and to cellular damage by monitoring plasma levels of hepatic enzymes. The clearance of antipyrine was not affected by naltrexone treatment, and, during the study period, the use and withdrawal of benzodiazepines and alcohol did not change this parameter; moreover, there was no relationship between changes in plasma hepatic enzymes and antipyrine half-life. Mean plasma levels of hepatic enzymes did not show significant modification in the course of treatment with naltrexone.
Collapse
Affiliation(s)
- L A Pini
- Clinical Pharmacology Department, University of Modena, Italy
| | | | | | | | | |
Collapse
|
27
|
Boobis AR, Sesardic D, Murray BP, Edwards RJ, Singleton AM, Rich KJ, Murray S, de la Torre R, Segura J, Pelkonen O. Species variation in the response of the cytochrome P-450-dependent monooxygenase system to inducers and inhibitors. Xenobiotica 1990; 20:1139-61. [PMID: 2275211 DOI: 10.3109/00498259009046835] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. In the safety evaluation of drugs and other chemicals it is important to evaluate their possible inducing and inhibitory effects on the enzymes of drug metabolism. 2. While many similarities exist between species in their response to inducers and inhibitors, there are also important differences. Possible mechanisms of such variation are considered, with particular reference to the cytochrome P-450 system. 3. Differences in inhibition may be due to differences in inhibitory site of the enzyme involved, which is not always the active site of the enzyme, in competing pathways or in the pharmacokinetics of the inhibitor. 4. Differences in induction could be due to differences in the nature of the induction mechanism, in the isoenzyme induced, in tissue- or age-dependent regulation, in competing pathways for the substrate or its products, or in the pharmacokinetics of the inducing agent. 5. Examples of each of these possible differences are considered, often from our own work on the P450 IA subfamily, and results in animals are compared with those in humans, where possible. 6. At present, the differences between species in their response to inducers and inhibitors make extrapolation to humans from the results of animal studies difficult, so that ultimately such effects should be studied in the species of interest, humans.
Collapse
Affiliation(s)
- A R Boobis
- Department of Clinical Pharmacology, Royal Postgraduate Medical School, London, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Park BK, Kitteringham NR. Assessment of enzyme induction and enzyme inhibition in humans: toxicological implications. Xenobiotica 1990; 20:1171-85. [PMID: 2275213 DOI: 10.3109/00498259009046837] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. The principal methods used for the assessment of enzyme induction and enzyme inhibition are measurement of the pharmacokinetics of a model compound (probe drug), analysis of drug metabolism in vitro, and determination of changes in the disposition of, and endogenous substrate for, the enzyme of interest. 2. Probe drugs that have been used for this purpose include antipyrine, aminopyrine, tolbutamide, caffeine, theophylline, warfarin, oxazepam and paracetamol. Measurement of the excretion of metabolites of cortisol and oestradiol, which are endogenous substrates for cytochrome P450 IIIA enzymes, provides a non-invasive means of assessing enzyme induction or inhibition. 3. Combined pharmacokinetic/pharmacodynamic studies are required to assess the pharmacological relevance of either induction or inhibition of the enzymes involved in drug metabolism. 4. At present it is difficult to assess the toxicological implications of enzyme induction and inhibition in man. Safe probe drugs are required for the enzymes primarily responsible for drug detoxication, such as epoxide hydrolase and glutathione transferase, in order to identify individuals particularly at risk.
Collapse
Affiliation(s)
- B K Park
- Department of Pharmacology and Therapeutics, University of Liverpool, UK
| | | |
Collapse
|
29
|
Witkamp R, van 't Klooster G, van Miert A. The influence of gender and gonadal hormones on the plasma clearance and metabolite formation of antipyrine in ruminants. Eur J Pharmacol 1990. [DOI: 10.1016/0014-2999(90)93009-f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
30
|
Pilla AM, Zarowitz BJ, Svensson CK, Peterson EL, Popovich J. Bioimpedance assessment of antipyrine pharmacokinetics before and after enzyme induction. DICP : THE ANNALS OF PHARMACOTHERAPY 1990; 24:575-80. [PMID: 2360333 DOI: 10.1177/106002809002400602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bioimpedance (BI) technology, a noninvasive method of measuring body composition, has been previously used to develop a predictive model for metabolic clearance under basal conditions. The present investigation was conducted to assess the ability of BI-derived models to predict drug disposition in a perturbed system. An antipyrine pharmacokinetic and impedance analysis of 15 healthy male subjects was performed before and on the 14th day of phenobarbital administration (i.e., after enzyme induction). The all subsets multiple regression technique was used to develop preinduction models for clearance (CI), (p = 0.021, R2 = 0.654) and volume of distribution at steady-state (Vdss) (p = 0.001, R2 = 0.867), using demographic and mean BI parameters. The preinduction Cl model significantly underestimated postinduction measurements and was not predictive of changes in Cl. The preinduction Vdss model was predictive of postinduction Vdss. It appears that the BI-derived model is unable to predict perturbations in metabolic clearance caused by enzyme induction.
Collapse
Affiliation(s)
- A M Pilla
- Henry Ford Hospital, Detroit, MI 48202
| | | | | | | | | |
Collapse
|
31
|
Loft S. Metronidazole and antipyrine as probes for the study of foreign compound metabolism. PHARMACOLOGY & TOXICOLOGY 1990; 66 Suppl 6:1-31. [PMID: 2184425 DOI: 10.1111/j.1600-0773.1990.tb01611.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The aim of the present work was to develop a tool for the study of the enzyme activities relevant for the biotransformation of foreign compounds, their elimination and/or activation to toxic substances. The activity of an enzyme may be assessed by the rate of metabolism of a preferably specific probe or model compound. The cytochrome P450'ies, the key enzymes for the elimination and/or activation of most foreign compounds, exist in multiple forms with variable substrate specificity and regulation. Some cytochrome P450'ies are under genetic control, whereas the activity of others is mainly regulated by the influence from factors in the environment. Only some of the cytochrome P450'ies are relevant for the formation of harmful metabolites. Thus, the activity of as many cytochrome P450 forms as possible should be assessable, preferably simultaneously. The present work evaluated metronidazole in a cocktail with antipyrine as a tool for the study of the regulation of foreign compound metabolism in the liver. The cytochrome P450 catalyzed metabolism of metronidazole and antipyrine was studied in humans and in isolated rat hepatocytes. In humans the influence of dose, route of administration, enzyme induction and inhibition and liver disease was investigated. Rats of either sex were studied with and without pretreatment with specific enzyme inducers and incubations included specific enzyme inhibitors. Evidence was provided that the oxidative formation of the five major metabolites, two from metronidazole and three from antipyrine, depends on different cytochrome P450'ies. In humans it was demonstrated that the clearance of metronidazole and antipyrine could be determined from the same saliva sample collected 16-24 hours after their oral administration and so could the clearance for formation of each metabolite if urine was collected for 48 hours. Thus, with the cocktail of metronidazole and antipyrine and simple non-invasive sampling the activity of five different cytochrome P450'ies can be assessed in vivo. In addition, metronidazole may also be used for assessment of the glucuronidation capacity although this is a minor pathway in man. Because the variation within subjects is much less than between them, the cocktail test is particularly suited for paired designs with measurements before and after an environmental change and the subjects serving as their own control. The metronidazole/antipyrine cocktail may have many applications in the study of the regulation of foreign compound metabolism in man and in animals, in vivo and in vitro.
Collapse
|
32
|
Abstract
The rate and extent of drug metabolism significantly influences drug effect. Enzyme induction by increasing the metabolism of drugs may result in important drug interactions. Other implications of enzyme induction include alterations in the metabolism of endogenous substrates, vitamins and activity of extrahepatic enzyme systems. Similarly a wide range of drugs may produce clinically significant drug interactions following enzyme inhibition. Assessment of enzyme induction and inhibition in man involves diverse methods including the use of model drugs.
Collapse
Affiliation(s)
- M Barry
- Department of Pharmacology and Therapeutics, Trinity College Medical School, St James's Hospital, Dublin, Ireland
| | | |
Collapse
|
33
|
Bachmann K. Predicting toxicokinetic parameters in humans from toxicokinetic data acquired from three small mammalian species. J Appl Toxicol 1989; 9:331-8. [PMID: 2592732 DOI: 10.1002/jat.2550090509] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Values for the independent kinetic variables, clearance (CL) and volume of distribution (V), for six xenobiotics--antipyrine, ethosuximide, phencyclidine, theophylline, valproic acid and warfarin--were culled from the literature for each of three small subhuman species and for humans, and then allometrically scaled. Scaling was performed in two ways. First, using kinetic data acquired for three small subhuman species and for man, scaled parameters were observed for goodness of fit to a standard allometric expression. Second, scaled parameters were averaged for three subhuman species. Mean scaled kinetic parameters from only three species were used to predict half-life values of the xenobiotics in humans. Finally, predicted percentages of the xenobiotic burdens remaining in humans at the end of four allometrically-predicted half-lives were compared with the expected percentages of remaining xenobiotic based upon four actual half-lives in humans. The results suggest that it may be feasible to estimate, using three small subhuman species, allometrically-derived toxicokinetic parameters of some substances in man with sufficient accuracy to be of practical value.
Collapse
Affiliation(s)
- K Bachmann
- Department of Pharmacology, College of Pharmacy, University of Toledo, OH 43606
| |
Collapse
|
34
|
Adebayo GI, Ogundipe TO. Effects of salbutamol on the absorption and disposition of sulphamethoxazole in adult volunteers. Eur J Drug Metab Pharmacokinet 1989; 14:57-60. [PMID: 2759134 DOI: 10.1007/bf03190842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
On the basis of the reports that beta-adrenergic stimulation affects gastrointestinal motility in man as well as induces N-acetyltransferase in rat pineal gland, we decided to assess the effects of salbutamol pretreatment on the absorption as well as disposition of sulphamethoxazole (SMZ). After a control pharmacokinetic study of SMZ, each of six healthy volunteers took salbutamol at a dose of 4 mg four times daily for two weeks, and the kinetic study of SMZ was repeated after the morning dose on the fifteenth day. None of SMZ half-life, volume of distribution, renal and hepatic clearance rates was significantly altered. However, salbutamol pretreatment resulted in significant reduction in the absorption rate constant of SMZ from 1.168 +/- 0.509 h-1 (mean +/- S.D.) to 0.688 +/- 0.348 h-1 (P less than 0.025), and this was associated with prolongation of tmax from 3.00 +/- 1.69 h to 4.33 +/- 1.51 h (P less than 0.025). Cmax, however, was not correspondingly reduced probably as a result of significant increase in the extent of SMZ absorption from 611 +/- 108 mg to 749 +/- 78 mg (P less than 0.025). Our findings suggest that beta-adrenergic stimulation does not significantly induce human hepatic N-acetyltransferase enzyme. However, it does reduce the absorption rate as well as increase the extent of absorption of SMZ.
Collapse
Affiliation(s)
- G I Adebayo
- Department of Pharmacology, College of Medicine, Lagos, Nigeria
| | | |
Collapse
|
35
|
Mikati MA, Szabo GK, Pylilo RJ, LeDuc BW, Browne TR, Greenblatt DJ. Improved high-performance liquid chromatographic assay of antipyrine, hydroxymethylantipyrine, 4-hydroxyantipyrine and norantipyrine in urine. JOURNAL OF CHROMATOGRAPHY 1988; 433:305-11. [PMID: 3235560 DOI: 10.1016/s0378-4347(00)80613-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- M A Mikati
- Department of Neurology, Boston University School of Medicine, MA 02118
| | | | | | | | | | | |
Collapse
|
36
|
Affiliation(s)
- H E Poulsen
- Department of Pharmacology, University of Copenhagen, Denmark
| | | |
Collapse
|
37
|
Mönig H, Wilhelmy J, John S, Ohnhaus EE. Biliary excretion of antipyrine and its metabolites after cholecystectomy. Br J Clin Pharmacol 1988; 25:279-80. [PMID: 3358892 PMCID: PMC1386487 DOI: 10.1111/j.1365-2125.1988.tb03304.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
|
38
|
Back DJ, Tjia J, Mönig H, Ohnhaus EE, Park BK. Selective inhibition of drug oxidation after simultaneous administration of two probe drugs, antipyrine and tolbutamide. Eur J Clin Pharmacol 1988; 34:157-63. [PMID: 3383988 DOI: 10.1007/bf00614553] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of sulphaphenazole, cimetidine and primaquine on the disposition of antipyrine and tolbutamide in healthy volunteers have been investigated. The model substrates were administered simultaneously in order more clearly to define any selective effects of the potential inhibitors. Sulphaphenazole produced a significant increase in the half-life of tolbutamide (7.10 to 21.50 h) and a corresponding decrease in its clearance (0.260 to 0.084 ml.min-1.kg-1). Clearance to hydroxytolbutamide (OHTOL) and carboxytolbutamide (COOHTOL) was also significantly decreased. In contrast, sulphaphenazole had no effect on the disposition of antipyrine. Administration of cimetidine did not significantly alter the disposition of either model drug. However, a 1.6-times higher dose of cimetidine did increase the half lives both of tolbutamide and antipyrine (6.21 to 9.04 h and 14.2 to 19.2 h, respectively) and decrease their clearance (0.226 to 0.148 and 0.50 to 0.31 ml.min-1 kg-1, respectively). Clearance to OHTOL and hydroxymethylantipyrine (HMA) was reduced. A single dose of primaquine had no demonstrable effect on tolbutamide disposition whereas the half-life of antipyrine was increased (12.1 to 15.0 h) and its clearance decreased (0.63 to 0.38 ml.min-1.kg-1). The partial clearance to HMA, 4-hydroxyantipyrine (OHA) and norantipyrine (NORA) was also significantly reduced. The two main inferences are first, that tolbutamide and antipyrine are metabolised by different forms of cytochrome P-450, and second that a battery of model substrates is needed to investigate the inhibitory effects of a drug in man.
Collapse
Affiliation(s)
- D J Back
- Department of Pharmacology and Therapeutics, University of Liverpool, England
| | | | | | | | | |
Collapse
|
39
|
Zysset T, Wietholtz H. Differential effect of type I and type II diabetes on antipyrine disposition in man. Eur J Clin Pharmacol 1988; 34:369-75. [PMID: 3402522 DOI: 10.1007/bf00542438] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
As the influence of diabetes on drug metabolism in patients is controversial, a study was performed to assess antipyrine (AP) disposition in controlled Type I and Type II diabetics and 2 age- and sex-matched control groups. In Type I diabetics, the half-life of AP was significantly reduced from 12.0 (controls) to 7.9 h, and the volume of distribution (V) was lowered from 733 to 569 ml.kg-1. The resulting plasma clearance and cumulative urinary excretion of AP and its metabolites over 24 h did not differ from controls. In Type II diabetics, the AP half-life (14.5 h) and V (568 ml.kg-1) did not differ from their age- and sex-matched controls (11.1 h and 643 ml.kg-1, respectively), but the plasma clearance of AP was significantly reduced by 30%, and urinary excretion was significantly reduced to 44% of controls. The differential effects of Types I and II diabetes on AP metabolism may explain, at least in part, the controversial data in the literature.
Collapse
Affiliation(s)
- T Zysset
- Department of Clinical Pharmacology University of Berne, Switzerland
| | | |
Collapse
|
40
|
Juma FD. Disposition of antipyrine in African patients with Hodgkin's lymphoma. Br J Clin Pharmacol 1987; 24:809-11. [PMID: 3440100 PMCID: PMC1386407 DOI: 10.1111/j.1365-2125.1987.tb03249.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The pharmacokinetics of antipyrine were studied in 12 healthy volunteers and 10 patients of Kenya African origin with Hodgkin's lymphoma. The half-life of antipyrine was 12.2 +/- 1.3 h (mean + s.d.), while the apparent volume of distribution (V) was 0.67 +/- 0.11 l kg-1 (mean +/- s.d.) and the total body clearance was 40.7 +/- 3.2 ml kg-1 h-1 (mean +/- s.d.) in the healthy volunteers. The antipyrine half-life in the patients with advanced Hodgkin's lymphoma was 17.1 +/- 2.7 h (mean +/- s.d.). The apparent volume of distribution was 0.72 +/- 0.14 l kg-1 (mean +/- s.d.) which was larger than in healthy volunteers (P less than 0.05). The total body clearance was 30.3 +/- 9.4 ml kg-1 h-1 (mean + s.d.) and this was reduced compared with that in healthy volunteers (P less than 0.02). After cytotoxic therapy the half-life in the patients with advanced Hodgkin's lymphoma was significantly decreased to 8.3 +/- 1.3 h (mean +/- s.d.) (P less than 0.07), and the apparent volume of distribution was reduced to 0.65 +/- 0.07 l kg-1 (mean +/- s.d.) (P less than 0.05) while the total body clearance increased to 52.8 +/- 5.5 ml kg-1 h-1 (mean +/- s.d.) (P less than 0.01).
Collapse
Affiliation(s)
- F D Juma
- Division of Clinical Pharmacology, College of Health Sciences, University of Nairobi, Kenya
| |
Collapse
|
41
|
Posner J, Danhof M, Teunissen MW, Breimer DD, Whiteman PD. The disposition of antipyrine and its metabolites in young and elderly healthy volunteers. Br J Clin Pharmacol 1987; 24:51-5. [PMID: 3620285 PMCID: PMC1386279 DOI: 10.1111/j.1365-2125.1987.tb03135.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
1 Oxidative metabolism of antipyrine (AP) was compared in 11 elderly (greater than 65 years) and 12 young (less than 40 years) volunteers. All subjects were non-smokers, consumed little if any alcohol and were in good health. 2 After a single dose of AP 500 mg, its clearance from saliva and profiles of the parent drug and its major metabolites in urine were determined using high-performance liquid chromatography. 3 Mean total AP clearance from saliva was lower in the elderly (P less than 0.05). Mean weight-normalised volume of distribution was also smaller (P less than 0.01) so that elimination half-life in the elderly was not significantly different from that in the young. 4 The percentage dose excreted in 48 h urine as norantipyrine (NORA) and its clearance for production were lower in the elderly (P less than 0.001 and P less than 0.01 respectively). Urinary 3-hydroxymethylantipyrine (HMA) and free antipyrine were present in greater quantities in 48 h urine in the elderly (P less than 0.001 and P less than 0.05) while the amounts of 4-hydroxyantipyrine (OHA) were almost identical in the two age groups. 5 The findings suggest that there is a selective impairment of N-demethylation in the elderly which may have important implications for dosage of elderly patients with drugs metabolised by this route.
Collapse
|
42
|
Heinemeyer G. Clinical pharmacokinetic considerations in the treatment of increased intracranial pressure. Clin Pharmacokinet 1987; 13:1-25. [PMID: 3304768 DOI: 10.2165/00003088-198713010-00001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Life-threatening increased intracranial pressure can be reversed by a variety of drugs. These compounds all have some disadvantages, producing rebound effects, severe coma or cardiovascular depression and electrolyte imbalance. However, reduction of intracranial pressure is a prerequisite for recovery and the benefits of treatment outweigh the risks. Dexamethasone is rapidly eliminated, the short half-life (about 3 hours) indicating that dosage intervals should be kept small. As yet, however, its therapeutic efficacy has not been clearly demonstrated. Therefore, an association between pharmacokinetics and pharmacodynamics cannot be established. Osmotic diuretics are the most widely used agents for reduction of intracranial pressure. Pharmacokinetics show a very close relationship to changes in serum osmolality, but there are large variations in the clearance. For the use of osmotics, the blood-brain barrier must be intact. Osmotic diuretics may lead to intracerebral oedema or to acute renal failure as serum osmolality increases. Considering the pharmacokinetics of each drug, and the dynamics of intracerebral pressure and osmolality, an intermittent, individually titrated dosage should be administered, with simultaneous monitoring of intracranial pressure. Frusemide (furosemide) can be used as an adjunct, to enhance the effect of osmotic diuretics. Its pharmacokinetics are limited by renal function, depending on age as well as on the extent of renal impairment. Altered renal elimination of concomitantly administered drugs, and electrolyte imbalances should be anticipated when diuretics are used. Barbiturates are certain to decrease intracranial pressure in humans by an as yet unknown mechanism. Their administration is recommended for patients that do not respond to conventional therapy. As barbiturates can result in deep coma, knowledge of their pharmacokinetics is of great importance for recovery. Following single doses, pentobarbitone has a relatively long elimination half-life (about 22 hours). However, after repeated administration for several days, its elimination may be enhanced due to autoinduction. Thiopentone kinetics are characterised by distribution and redistribution into deep peripheral compartments. Administration of high and frequent doses leads to considerably delayed recovery. This is not true for methohexitone, which shows comparable pharmacokinetics after single and multiple dose administration. Elimination depends on liver blood flow. Thus, recovery from methohexitone-coma is rapid. Rapid elimination is also an important characteristic of etomidate and alphaxalone/alphadolone, two non-barbiturate hypnotics.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
|
43
|
Affiliation(s)
- G C Farrell
- Department of Medicine, University of Sydney, Westmead Hospital, Australia
| |
Collapse
|
44
|
Loft S, Sonne J, Poulsen HE, Petersen KT, Jørgensen BG, Døssing M. Inhibition and induction of metronidazole and antipyrine metabolism. Eur J Clin Pharmacol 1987; 32:35-41. [PMID: 3582467 DOI: 10.1007/bf00609955] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effect of cimetidine, antipyrine and phenobarbitone on the pharmacokinetics of intravenous metronidazole and oral antipyrine has been examined in 7 healthy volunteers. The administration of cimetidine for 24 h before and throughout the sampling period failed to alter the total clearance of metronidazole or the rate of formation of the hydroxy metabolite, whereas the total and partial clearances of antipyrine were decreased 0.74 and 0.6-0.7-fold, respectively. Seven days of phenobarbitone or antipyrine administration increased the total clearance of metronidazole 1.51- and 1.86-fold, respectively, and the total antipyrine clearance was 1.22 or 1.46-fold increased, respectively. The rate of metronidazole hydroxylation was significantly enhanced by both enzyme inducers. The partial clearance of antipyrine to the normetabolite was significantly increased by both inducers, whereas the rate of 4-hydroxylation was significantly increased only by prior antipyrine administration. The results indicate that the hydroxylation of metronidazole is not inhibited by cimetidine, but that it is inducible by phenobarbitone or antipyrine. It is suggested that metronidazole and antipyrine are metabolized by different enzymatic pathways.
Collapse
|
45
|
Shaw PN, Hall ST, Houston JB. Effect of pregnenolone carbonitrile, promethazine and antipyrine pretreatment on antipyrine metabolite formation in rats. Xenobiotica 1986; 16:1109-16. [PMID: 3798958 DOI: 10.3109/00498258609038988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of three inducers of cytochrome P-450-mediated drug oxidations (Pregnenolone carbonitrile, promethazine and antipyrine) on antipyrine metabolite kinetics has been investigated using the urinary metabolite pattern and 14CO2 exhalation rate (CER)-time profile following [N-methyl-14C]antipyrine administration. The CER-time profiles showed the characteristic changes associated with induction, namely, increased maximum CER and decreased half-life, previously observed in phenobarbitone and beta-naphthaflavone-induced rats. Calculation of formation rate constants based on urinary recovery of 3-hydroxymethyl-, 4-hydroxy- and nor-antipyrine indicated no clear selectivity of induction by any pretreatment. However, the percentage increase of the latter two metabolites was two- to four-fold greater than for the former metabolite. The use of the metabolite ratio (3-hydroxymethylantipyrine/norantipyrine) is proposed to assess the qualitative nature of induction of antipyrine metabolism.
Collapse
|
46
|
Kubota K, Ishizaki T, Chiba K, Takagi A, Nakagawa A, Nakamura K. Antipyrine clearance and metabolism in patients with psoriasis. Br J Clin Pharmacol 1986; 22:455-62. [PMID: 3768257 PMCID: PMC1401161 DOI: 10.1111/j.1365-2125.1986.tb02917.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The kinetic parameters of antipyrine obtained from saliva samples and the appearance of major antipyrine metabolites (4-hydroxyantipyrine, norantipyrine and 3-hydroxymethylantipyrine) in urine samples were measured in 10 patients with psoriasis (six nonsmokers and four smokers) and in 20 healthy subjects (11 nonsmokers and nine smokers). The volume of distribution and total clearance of antipyrine were not significantly different between psoriatric patients and control subjects subdivided according to smoking habit. However, antipyrine half-life was significantly (P less than 0.05) shorter in nonsmoking psoriatrics than in nonsmoking controls. There were no significant differences in mean values for the amounts (% dose) and partial clearances for production of major antipyrine metabolites between non-smoking patients and non-smoking controls, between smoking patients and smoking controls, and between patients overall and controls overall. The total clearance of antipyrine and the partial clearances of antipyrine to its three main metabolites were significantly (P less than 0.05 to 0.01) greater in smoking controls than in nonsmoking controls, and the total clearance of antipyrine and the partial clearance to 4-hydroxyantipyrine were significantly (P less than or equal to 0.05) greater in smoking patients than in nonsmoking patients. These findings provide no evidence that psoriasis is associated with an alteration in hepatic microsomal monooxygenase activity, at least insofar as the formation of major antipyrine metabolites is concerned.
Collapse
|
47
|
Spoelstra P, Teunissen MW, Janssens AR, Weeda B, van Duijn W, Koch CW, Breimer DD. Antipyrine clearance and metabolite formation: the influence of liver volume and smoking. Eur J Clin Invest 1986; 16:321-7. [PMID: 3093244 DOI: 10.1111/j.1365-2362.1986.tb01349.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The influence of liver volume and cigarette smoking on antipyrine clearance and metabolite formation was studied in seventeen volunteers (eight smokers, nine non-smokers). Inter-test coefficient of variation of liver volume (as determined by ultrasound) was 6.3%. The mean antipyrine clearance was 49.3 +/- 18.3 ml min-1 and when normalized for liver volume 36.1 +/- 10.1 ml min-1 l-1. The antipyrine clearance per unit volume of liver was significantly higher in smokers (43.0 +/- 10.5 ml min-1 l-1), than in non-smokers (30.0 +/- 4.6 ml min-1 l-1) (P less than 0.01). No significant difference was found between the two groups as to the excreted amounts of 4-hydroxyantipyrine (OHA), norantipyrine (NORA), and 3-hydroxymethylantipyrine (HMA). Normalized for liver volume the mean clearances for production (Clm) of these metabolites were significantly higher in the group of smokers than in the group of non-smokers. The greatest change was observed for OHA formation. However, analysis of variance showed that the differences in the percentages of change of the mean Clm of these metabolites in the two groups are not significant.
Collapse
|
48
|
Buppodom P, Koga N, Yamada H, Yoshimura H. Studies on rat liver cytochrome P-450s involved in the metabolism of antipyrine: phenobarbital- and 3-methylcholanthrene-inducible isozymes possessing 4-hydroxylase activity. Biochem Pharmacol 1986; 35:1404-6. [PMID: 3964305 DOI: 10.1016/0006-2952(86)90291-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
49
|
Teunissen MW, Bruining GJ, De Jongh BM, Tenkate-Westerhof EW, Breimer DD. Antipyrine clearance and metabolite formation in children with congenital adrenal hyperplasia. Br J Clin Pharmacol 1985; 20:703-6. [PMID: 4092001 PMCID: PMC1400822 DOI: 10.1111/j.1365-2125.1985.tb05134.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Antipyrine salivary clearance and half-life and the rate of formation of three principal metabolites of antipyrine (4-hydroxyantipyrine, 3-hydroxymethylantipyrine and norantipyrine) were assessed in nine children with congenital adrenal hyperplasia, six of whom were salt-losers and three of whom were non-salt-losers. No differences were found in comparison with data obtained in normal children.
Collapse
|
50
|
Shaw PN, Houston JB, Rowland M, Hopkins K, Thiercelin JF, Morselli PL. Antipyrine metabolite kinetics in healthy human volunteers during multiple dosing of phenytoin and carbamazepine. Br J Clin Pharmacol 1985; 20:611-8. [PMID: 4091993 PMCID: PMC1400829 DOI: 10.1111/j.1365-2125.1985.tb05119.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Antipyrine total clearance and the formation clearance of its major metabolites were studied in normal, healthy male volunteers before and after multiple dosing for approximately three weeks with phenytoin (six subjects) and carbamazepine (six subjects). Total antipyrine clearance increased on average by 91% after phenytoin dosing and by 61% after carbamazepine and individual increases correlated well with mean plasma concentrations of the anti-epileptic drug. The increase in total clearance resulted largely from increased formation clearances of the 4-hydroxy and 3-hydroxymethylantipyrine metabolites with minimal effect on the norantipyrine pathway, following treatment with both enzyme-inducing drugs. It is concluded that both phenytoin and carbamazepine have similar effects on antipyrine metabolism and that these effects are mediated by induction of specific forms of cytochrome P450.
Collapse
|