Related Experiment Video

Updated: Jun 21, 2026

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS
08:38

Quantification of the Immunosuppressant Tacrolimus on Dried Blood Spots Using LC-MS/MS

Published on: November 8, 2015

Pharmacogenetics of calcineurin inhibitors in renal transplantation

Eliecer Coto1, Beatriz Tavira

  • 1Genética Molecular, Redinren, and Fundación Renal, Hospital Universitario Central de Asturias, Oviedo, Spain. eliecer.coto@sespa.princast.es

Transplantation
|August 12, 2009
PubMed

Insights

Genetic variations in CYP3A5 influence how the body processes tacrolimus (Tac), an immunosuppressant drug. Identifying the CYP3A5*3 genotype helps predict optimal starting doses for renal transplant patients, preventing toxicity and improving outcomes.

Area of Science:

  • Pharmacogenomics
  • Transplantation Medicine
  • Drug Metabolism

Background:

  • Cyclosporine A and tacrolimus (Tac) are critical immunosuppressants with narrow therapeutic ranges, necessitating precise dosing to avoid organ rejection or toxicity.
  • Significant interindividual pharmacokinetic variability in these calcineurin inhibitors complicates initial dose determination.
  • Drug bioavailability is influenced by absorption, biotransformation, and elimination, processes largely governed by cytochrome P450 enzymes and efflux pumps.

Purpose of the Study:

  • To investigate the role of genetic variants, specifically in CYP3A4 and CYP3A5, in the interindividual metabolism of Cyclosporine A and Tac.
  • To determine if specific single nucleotide polymorphisms (SNPs) in CYP3A4/CYP3A5 genes correlate with differences in drug clearance.
  • To evaluate the predictive value of the CYP3A5*3 genotype for optimizing tacrolimus starting dosage in renal transplant recipients.

Main Methods:

  • Analysis of DNA variants within the CYP3A4 and CYP3A5 genes.
  • Correlation of identified SNPs with observed drug clearance rates.
  • Comparison of tacrolimus clearance in renal transplant recipients based on CYP3A5 genotype (wild-type vs. CYP3A5*3 homozygotes).

Main Results:

  • Single nucleotide polymorphisms in CYP3A4 and CYP3A5 genes are associated with variable drug clearance.
  • Individuals homozygous for the CYP3A5*3 non-expression allele exhibit significantly lower tacrolimus clearance compared to CYP3A5 expressors.
  • The CYP3A5*3 genotype is identified as a key genetic factor influencing tacrolimus pharmacokinetics.

Conclusions:

  • The CYP3A5*3 genotype is the sole reported genetic predictor for establishing appropriate initial tacrolimus dosages.
  • Genotyping for CYP3A5*3 can help avoid tacrolimus overdosing and underdosing in renal transplant patients.
  • Personalized dosing strategies based on CYP3A5 genotype can improve the clinical outcomes of renal transplantation.

More Related Videos

TBase - an Integrated Electronic Health Record and Research Database for Kidney Transplant Recipients09:00

TBase - an Integrated Electronic Health Record and Research Database for Kidney Transplant Recipients

Published on: April 13, 2021

Related Concept Videos

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu01:29

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu

Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...
Pharmacogenomics: Identification of New Drug Targets01:29

Pharmacogenomics: Identification of New Drug Targets

Advances in genomics have profoundly influenced drug discovery by increasing both the speed and accuracy of pharmaceutical development. Pharmacogenomics, which examines how genetic variation influences drug response, facilitates the identification of novel therapeutic targets and enables patient stratification for personalized treatment. These strategies contribute to improved drug efficacy, minimized adverse effects, and more efficient clinical trial design.Mapping genetic differences...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters01:16

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...