Pharmacogenetic Determinants of Human Liver Microsomal Alfentanil Metabolism and the Role of Cytochrome P450 3A5

Background:There is considerable unexplained interindividual variability in the clearance of alfentanil. Alfentanil undergoes extensive metabolism by cytochrome P4503A4 (CYP3A4). CYP3A5 is structurally similar to CYP3A4 and metabolizes most CYP3A4 substrates but is polymorphically expressed. Livers with the CYP3A5*1 allele contain higher amounts of the native CYP3A5 protein than livers homozygous for the mutant CYP3A5*3 allele. This investigation tested the hypothesis that alfentanil is a substrate for CYP3A5 and that CYP3A5 pharmacogenetic variability influences human liver alfentanil metabolism. Methods:Alfentanil metabolism to noralfentanil and N-phenylpropionamide was determined in microsomes from two groups of human livers, characterized for CYP3A4 and CYP3A5 protein content: low CYP3A5 (2.0–5.2% of total CYP3A, n = 10) and high CYP3A5 (46–76% of total CYP3A, n = 10). Mean CYP3A4 content was the same in both groups. The effects of the CYP3A inhibitors troleandomycin and ketoconazole, the latter being more potent toward CYP3A4, on alfentanil metabolism were also determined. Results:In the low versus high CYP3A5 livers, respectively, noralfentanil formation was 77 ± 31 versus 255 ± 170 pmol · min−1 · mg−1, N-phenylpropionamide formation was 8.0 ± 3.1 versus 20.5 ± 14.0 pmol · min−1 · mg−1, and the metabolite ratio was 9.5 ± 0.4 versus 12.7 ± 1.4 (P < 0.05 for all). There was a poor correlation between alfentanil metabolism and CYP3A4 content but an excellent correlation when CYP3A5 (i.e., total CYP3A content) was considered (r2 = 0.81, P < 0.0001). Troleandomycin inhibited alfentanil metabolism similarly in the low and high CYP3A5 livers; ketoconazole inhibition was less in the high CYP3A5 livers. Conclusion:In microsomes from human livers expressing the CYP3A5*1 allele and containing higher amounts of CYP3A5 protein, compared with those with the CYP3A5*3 allele and little CYP3A5, there was greater alfentanil metabolism, metabolite ratios more closely resembled those for expressed CYP3A5, and inhibitors with differing CYP3A4 and CYP3A5 selectivities had effects resembling those for expressed CYP3A5. Therefore, alfentanil is metabolized by human liver microsomal CYP3A5 in addition to CYP3A4, and pharmacogenetic variability in CYP3A5 expression significantly influences human liver alfentanil metabolism in vitro. Further investigation is warranted to assess whether the CYP3A5 polymorphism is a factor in the interindividual variability of alfentanil metabolism and clearance in vivo.

[1]  R. Kim,et al.  Genetic variability in CYP3A5 and its possible consequences. , 2004, Pharmacogenomics.

[2]  Yang Dai,et al.  In vitro metabolism of cyclosporine A by human kidney CYP3A5. , 2004, Biochemical pharmacology.

[3]  E. Kharasch,et al.  Intravenous and oral alfentanil as in vivo probes for hepatic and first‐pass cytochrome P450 3A activity: Noninvasive assessment by use of pupillary miosis , 2004, Clinical pharmacology and therapeutics.

[4]  Yvonne S. Lin,et al.  Differences in the inhibition of cytochromes P450 3A4 and 3A5 by metabolite-inhibitor complex-forming drugs. , 2004, Drug metabolism and disposition: the biological fate of chemicals.

[5]  G. Wilkinson Genetic variability in cytochrome P450 3A5 and in vivo cytochrome P450 3A activity: Some answers but still questions , 2004, Clinical pharmacology and therapeutics.

[6]  S. Masuda,et al.  CYP3A5*1-carrying graft liver reduces the concentration/oral dose ratio of tacrolimus in recipients of living-donor liver transplantation. , 2004, Pharmacogenetics.

[7]  J. Brockmöller,et al.  Limited contribution of CYP3A5 to the hepatic 6β-hydroxylation of testosterone , 2004, Naunyn-Schmiedeberg's Archives of Pharmacology.

[8]  C. Clarke,et al.  CYP3A5 Genotype and Midazolam Clearance in Australian Patients Receiving Chemotherapy , 2004, Clinical pharmacology and therapeutics.

[9]  P. Syrris,et al.  The Influence of Pharmacogenetics on the Time to Achieve Target Tacrolimus Concentrations after Kidney Transplantation , 2004, American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons.

[10]  A. Telenti,et al.  Pharmacokinetics of midazolam in CYP3A4- and CYP3A5-genotyped subjects , 2004, European Journal of Clinical Pharmacology.

[11]  J. Squifflet,et al.  The effect of CYP3A5 and MDR1 (ABCB1) polymorphisms on cyclosporine and tacrolimus dose requirements and trough blood levels in stable renal transplant patients. , 2004, Pharmacogenetics.

[12]  J. Fitzloff,et al.  Differential enantioselectivity and product-dependent activation and inhibition in metabolism of verapamil by human CYP3As. , 2004, Drug metabolism and disposition: the biological fate of chemicals.

[13]  J. Williams,et al.  A significant drug-metabolizing role for CYP3A5? , 2003, Drug metabolism and disposition: the biological fate of chemicals.

[14]  P. Beaune,et al.  Impact of cytochrome P450 3A5 genetic polymorphism on tacrolimus doses and concentration-to-dose ratio in renal transplant recipients12 , 2003, Transplantation.

[15]  K. Thummel Does the CYP3A5*3 polymorphism affect in vivo drug elimination? , 2003, Pharmacogenetics.

[16]  R. Kim,et al.  Genotype-phenotype associations for common CYP3A4 and CYP3A5 variants in the basal and induced metabolism of midazolam in European- and African-American men and women. , 2003, Pharmacogenetics.

[17]  W. Weimar,et al.  Genetic polymorphisms of the CYP3A4, CYP3A5, and MDR‐1 genes and pharmacokinetics of the calcineurin inhibitors cyclosporine and tacrolimus , 2003, Clinical pharmacology and therapeutics.

[18]  D. Greenblatt,et al.  In vitro metabolism of midazolam, triazolam, nifedipine, and testosterone by human liver microsomes and recombinant cytochromes p450: role of cyp3a4 and cyp3a5. , 2003, Drug metabolism and disposition: the biological fate of chemicals.

[19]  M. Ingelman-Sundberg,et al.  Comparative analysis of CYP3A expression in human liver suggests only a minor role for CYP3A5 in drug metabolism. , 2003, Drug metabolism and disposition: the biological fate of chemicals.

[20]  E. Schuetz,et al.  Tacrolimus Dosing in Pediatric Heart Transplant Patients is Related to CYP3A5 and MDR1 Gene Polymorphisms , 2003, American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons.

[21]  E. Kharasch,et al.  Disposition and miotic effects of oral alfentanil: A potential noninvasive probe for first‐pass cytochrome P4503A activity , 2003, Clinical pharmacology and therapeutics.

[22]  A. Kalgutkar,et al.  Assessment of the contributions of CYP3A4 and CYP3A5 in the metabolism of the antipsychotic agent haloperidol to its potentially neurotoxic pyridinium metabolite and effect of antidepressants on the bioactivation pathway. , 2003, Drug metabolism and disposition: the biological fate of chemicals.

[23]  P. Syrris,et al.  Tacrolimus pharmacogenetics: polymorphisms associated with expression of cytochrome p4503A5 and p-glycoprotein correlate with dose requirement , 2002, Transplantation.

[24]  E. Burton,et al.  Involvement of CYP3A in the metabolism of eplerenone in humans and dogs: differential metabolism by CYP3A4 and CYP3A5. , 2002, Drug metabolism and disposition: the biological fate of chemicals.

[25]  Jin‐ding Huang,et al.  Pharmacokinetics of midazolam and 1'-hydroxymidazolam in Chinese with different CYP3A5 genotypes. , 2002, Drug metabolism and disposition: the biological fate of chemicals.

[26]  E. Schuetz,et al.  Genetic contribution to variable human CYP3A-mediated metabolism. , 2002, Advanced drug delivery reviews.

[27]  B. Goh,et al.  Explaining interindividual variability of docetaxel pharmacokinetics and pharmacodynamics in Asians through phenotyping and genotyping strategies. , 2002, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[28]  B. Ring,et al.  Comparative metabolic capabilities of CYP3A4, CYP3A5, and CYP3A7. , 2002, Drug metabolism and disposition: the biological fate of chemicals.

[29]  E. Schuetz,et al.  Co-regulation of CYP3A4 and CYP3A5 and contribution to hepatic and intestinal midazolam metabolism. , 2002, Molecular pharmacology.

[30]  E. Kharasch,et al.  A pilot evaluation of alfentanil‐induced miosis as a noninvasive probe for hepatic cytochrome P450 3A4 (CYP3A4) activity in humans , 2001, Clinical pharmacology and therapeutics.

[31]  Ann Daly,et al.  Sequence diversity in CYP3A promoters and characterization of the genetic basis of polymorphic CYP3A5 expression , 2001, Nature Genetics.

[32]  E. Kharasch,et al.  Intraindividual Variability in Male Hepatic CYP3A4 Activity Assessed by Alfentanil and Midazolam Clearance , 1999, Journal of clinical pharmacology.

[33]  D. Shen,et al.  Inhibition of cytochrome P-450 3A (CYP3A) in human intestinal and liver microsomes: comparison of Ki values and impact of CYP3A5 expression. , 1999, Drug metabolism and disposition: the biological fate of chemicals.

[34]  E. Kharasch,et al.  Assessment of Cytochrome P450 3A4 Activity during the Menstrual Cycle Using Alfentanil as a Noninvasive Probe , 1997, Anesthesiology.

[35]  E. Kharasch,et al.  The Role of Cytochrome P450 3A4 in Alfentanil Clearance: Implications for Interindividual Variability in Disposition and Perioperative Drug Interactions , 1997, Anesthesiology.

[36]  P. Beaune,et al.  Possible involvement of multiple cytochrome P450S in fentanyl and sufentanil metabolism as opposed to alfentanil. , 1997, Biochemical pharmacology.

[37]  G. Wilkinson Cytochrome P4503A (CYP3A) metabolism: Prediction ofIn Vivo activity in humans , 1996, Journal of Pharmacokinetics and Biopharmaceutics.

[38]  F. Gonzalez,et al.  Specificity of substrate and inhibitor probes for cytochrome P450s: evaluation of in vitro metabolism using cDNA-expressed human P450s and human liver microsomes. , 1996, Xenobiotica; the fate of foreign compounds in biological systems.

[39]  W. Trager,et al.  Catalytic role of cytochrome P4503A4 in multiple pathways of alfentanil metabolism. , 1995, Drug metabolism and disposition: the biological fate of chemicals.

[40]  H. Yamazaki,et al.  Expression of cytochrome P450 3A5 in Escherichia coli: effects of 5' modification, purification, spectral characterization, reconstitution conditions, and catalytic activities. , 1995, Archives of biochemistry and biophysics.

[41]  C. Wandel,et al.  Midazolam is metabolized by at least three different cytochrome P450 enzymes. , 1994, British journal of anaesthesia.

[42]  E. Kharasch,et al.  Gas chromatographic-mass spectrometric analysis of alfentanil metabolites. Application to human liver microsomal alfentanil biotransformation. , 1994, Journal of chromatography. B, Biomedical applications.

[43]  D. Waxman,et al.  Evaluation of triacetyloleandomycin, alpha-naphthoflavone and diethyldithiocarbamate as selective chemical probes for inhibition of human cytochromes P450. , 1994, Archives of biochemistry and biophysics.

[44]  S D Hall,et al.  Regioselective biotransformation of midazolam by members of the human cytochrome P450 3A (CYP3A) subfamily. , 1994, Biochemical pharmacology.

[45]  A. Liapis,et al.  Perfusion chromatography: Effect of micropore diffusion on column performance in systems utilizing perfusive adsorbent particles with a bidisperse porous structure , 1994 .

[46]  F. Guengerich,et al.  Identification of the pharmacogenetic determinants of alfentanil metabolism: cytochrome P-450 3A4. An explanation of the variable elimination clearance. , 1992, Anesthesiology.

[47]  A. Wood,et al.  ACUTE EFFECT OF HALOTHANE (H) ON DRUG DISTRIBUTION , 1989 .

[48]  T. Kronbach,et al.  Oxidation of midazolam and triazolam by human liver cytochrome P450IIIA4. , 1989, Molecular pharmacology.

[49]  J. Heykants,et al.  Alfentanil Pharmacokinetics and Metabolism in Humans , 1988, Anesthesiology.

[50]  J. Heykants,et al.  Is the Metabolism of Alfentanil Subject to Debrisoquine Polymorphism? A Study Using Human Liver Microsomes , 1988, Anesthesiology.

[51]  J. Azuma,et al.  CYP3A5 genotype did not impact on nifedipine disposition in healthy volunteers , 2004, The Pharmacogenomics Journal.

[52]  L. Wojnowski,et al.  Cytochrome P450 3A and their regulation , 2004, Naunyn-Schmiedeberg's Archives of Pharmacology.

[53]  J. Williams,et al.  A SIGNIFICANT DRUG-METABOLIZING ROLE FOR CYP 3 A 5 ? , 2003 .

[54]  J. Spence,et al.  Pharmacokinetic-Pharmacodynamic Consequences and Clinical Relevance of Cytochrome P450 3A4 Inhibition , 2000, Clinical pharmacokinetics.

[55]  K. Thummel,et al.  In vitro and in vivo drug interactions involving human CYP3A. , 1998, Annual review of pharmacology and toxicology.

[56]  D R Stanski,et al.  Population pharmacokinetics of alfentanil: the average dose-plasma concentration relationship and interindividual variability in patients. , 1987, Anesthesiology.

[57]  C. Meistelman,et al.  A comparison of alfentanil pharmacokinetics in children and adults. , 1987, Anesthesiology.

[58]  G D Sweeney,et al.  Variability in the human drug response. , 1983, Thrombosis research. Supplement.