TABLE 1

Summary of in vitro inhibition data for CYP1A2, CYP2C9, CYP2C19, and CYP2D6 for 27 drugs Values represent the mean ± S.E. When IC50 was greater than 300 μM, the percent inhibition value at 300 μM was included (in parentheses).


Drug

IC50
CYP1A2
CYP2C9
CYP2C19
CYP2D6
μM
Cimetidine >300 (16%) >300 (22%) 100 ± 10 130 ± 10
Citalopram >300 (7%) >300 (20%) >300 (41%) 30 ± 3
Clarithromycin >300 (8%) >300 (4%) >300 (11%) >300 (6%)
Dicumarol ND 0.21 ± 0.01 ND ND
Diltiazem >300 (4%) >300 (53%) 170 ± 10 >300 (43%)
Diphenhydramine ND ND ND 12 ± 1
Disulfiram 1.3 ± 0.3 0.96 ± 0.32 5.5 ± 1.1 12 ± 2
Enoxacin 220 ± 20 ND ND ND
Erythromycin >300 (9%) >300 (6%) >300 (16%) >300 (4%)
Fluconazole >300 (17%) 11 ± 1 5.8 ± 0.2 170 ± 20
Fluoxetine 240 ± 70 33 ± 6 14 ± 2 0.27 ± 0.02
Fluvoxamine 0.035 ± 0.003 6.1 ± 0.2 0.35 ± 0.01 5.2 ± 0.7
Ketoconazole 25 ± 9 5.9 ± 0.6 9.4 ± 1.2 28 ± 6
Metronidazole >300 (12%) >300 (0%) >300 (1%) >300 (0%)
Moclobemide ND ND 160 ± 5 ND
Nefazodone 52 ± 15 17 ± 2 20 ± 5 11 ± 2
Paroxetine 8.4 ± 0.5 130 ± 20 22 ± 4 0.32 ± 0.02
Propranolol 17 ± 2 >300 (18%) 79 ± 16 6.6 ± 0.2
Quinidine ND ND ND 0.058 ± 0.004
Ranitidine >300 (0%) >300 (5%) >300 (8%) >300 (16%)
Risperidone >300 (3%) 280 ± 20 290 ± 30 12 ± 1
Roxithromycin >300 (4%) >300 (1%) >300 (5%) 250 ± 50
Sertraline 13 ± 2 81 ± 19 4.2 ± 0.6 1.8 ± 0.1
Sulfaphenazole ND 0.28 ± 0.03 ND ND
Terbinafine 12 ± 1 >300 (33%) 17 ± 4 0.041 ± 0.002
Ticlopidine 11 ± 1 110 ± 10 0.78 ± 0.15 4.0 ± 0.5
Troleandomycin
300 (10%)
>300 (16%)
>300 (17%)
>300 (16%)
  • ND, not determined.