In vitro approach to assess the potential for risk of idiosyncratic adverse reactions caused by candidate drugs

Chem Res Toxicol. 2012 Aug 20;25(8):1616-32. doi: 10.1021/tx300091x. Epub 2012 May 31.


Idiosyncratic adverse drug reactions (IADRs) in humans can result in a broad range of clinically significant toxicities leading to attrition during drug development as well as postlicensing withdrawal or labeling. IADRs arise from both drug and patient related mechanisms and risk factors. Drug related risk factors, resulting from parent compound or metabolites, may involve multiple contributory mechanisms including organelle toxicity, effects related to compound disposition, and/or immune activation. In the current study, we evaluate an in vitro approach, which explored both cellular effects and covalent binding (CVB) to assess IADR risks for drug candidates using 36 drugs which caused different patterns and severities of IADRs in humans. The cellular effects were tested in an in vitro Panel of five assays which quantified (1) toxicity to THLE cells (SV40 T-antigen-immortalized human liver epithelial cells), which do not express P450s, (2) toxicity to a THLE cell line which selectively expresses P450 3A4, (3) cytotoxicity in HepG2 cells in glucose and galactose media, which is indicative of mitochondrial injury, (4) inhibition of the human bile salt export pump, BSEP, and (5) inhibition of the rat multidrug resistance associated protein 2, Mrp2. In addition, the CVB Burden was estimated by determining the CVB of radiolabeled compound to human hepatocytes and factoring in both the maximum prescribed daily dose and the fraction of metabolism leading to CVB. Combining the aggregated results from the in vitro Panel assays with the CVB Burden data discriminated, with high specificity (78%) and sensitivity (100%), between 27 drugs, which had severe or marked IADR concern, and 9 drugs, which had low IADR concern, we propose that this integrated approach has the potential to enable selection of drug candidates with reduced propensity to cause IADRs in humans.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 11
  • ATP-Binding Cassette Transporters / chemistry
  • ATP-Binding Cassette Transporters / metabolism
  • Animals
  • Cell Line
  • Cell Survival / drug effects
  • Cytochrome P-450 CYP3A / metabolism
  • Galactose / pharmacology
  • Glucose / pharmacology
  • Hep G2 Cells
  • Humans
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins / metabolism
  • Prodrugs / adverse effects*
  • Prodrugs / metabolism
  • Prodrugs / toxicity
  • Rats
  • Rats, Sprague-Dawley
  • Risk Factors


  • ABCB11 protein, human
  • ABCC2 protein, human
  • ATP Binding Cassette Transporter, Subfamily B, Member 11
  • ATP-Binding Cassette Transporters
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins
  • Prodrugs
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • Glucose
  • Galactose