TABLE 6

IC50 values obtained for a series of compounds in different CYP2D6 assays


Compound

Fluorescent Probe in Intact Cells

Conventional Probe in Liver Microsomes
IC50a
Type of Inhibitorb
IC50
Type of Inhibitor
Quinidine 0.4 potent <0.3 potent
Ketoconazole 1.4 potent 78.4 poor
Nifedipine 7.7 moderate >30 poor
Amiodarone 11.0 moderate 28.1 moderate
Verapamil 12.6 moderate 18.0 moderate
Cyclosporine 14.7 moderate 98.0 poor
Quinine 18.1 moderate 11.8 moderate
Omeprazole 18.5 moderate 53.2 poor
Ticlopidine 25.2 moderate 28.4 moderate
Cimetidine 33.2 poor 114 poor
Tranylcypromine 192 poor 137 poor
Erythromycin 219 poor >300 noninhibitor
Sulfaphenazole 253 poor >300 noninhibitor
Quercetin 263 poor 287 poor
Diethyldithiocarbamate >300 noninhibitor >300 noninhibitor
Furafylline >300 noninhibitor >300 noninhibitor
Lovastatin
>300
noninhibitor
>300
noninhibitor
  • a IC50 (μM) data are the mean of two independent assays

  • b The compounds were classified as potent (IC50 <3 μM), moderate (IC50 from 3 to 30 μM), poor (IC50 from 30 to 300 μM), or noninhibitor (IC50 >300 μM)