In vitro systems for evaluating CYP inhibitory activity of citalopram stereoisomers and metabolites
| CYP Isoform | Substrate (with Concentration) | Product | Index Inhibitor (Mean ± S.E. IC50) |
|---|---|---|---|
| 1A2 | Phenacetin (100 μM) | Acetaminophen | α-Naphthoflavone (0.2 ± 0.05 μM) |
| 2C9 | Tolbutamide (100 μM) | Hydroxytolbutamide | Sulfaphenazole (1.3 ± 0.04 μM) |
| 2C19 | S-Mephenytoin (25 μM) | 4′-Hydroxymephenytoin | Omeprazole (4.2 ± 0.08 μM) |
| 2D6 | Dextromethorphan (25 μM) | Dextrorphan | Quinidine (0.43 ± 0.05 μM) |
| 2E1 | Chlorzoxazone (50 μM) | 6-Hydroxychlorozoxazone | Diethydithiocarbamate (16.6 ± 3.2 μM)1-a |
| 3A | Triazolam (250 μM) | α-Hydroxytriazolam | Ketoconazole (0.07 ± 0.01 μM) |
↵1-a Preincubated with microsomes prior to addition of substrate.