TABLE 1

Results of an in vitro screening assay to identify compounds that selectively inhibit M2 formation (but not M1 formation) from tramadol by dog liver microsomes

Shown are the formation rates of M1 and M2 from tramadol in pooled DLMs incubated with each of 85 different compounds at 1 and 100 µM inhibitor concentrations. Results are presented as the percentage of control (no inhibitor added) activity and are the average of triplicate determinations conducted in a single experiment.

InhibitorM1 Formation (% Control)M2 Formation (% Control)
1 µM Inhibitor100 µM Inhibitor1 µM Inhibitor100 µM Inhibitor
Acepromazine92209484
Acetaminophen95929395
Alfaxalone93519068
Amytriptylline950.914825
Artemisinin9566737
Acetylsalicylic acid93949196
Atipamezole180.165
Bupivacaine3219123
Buprenorphine8449743
Bupropion94169347
Carbamazepine95549152
Carprofen96619546
Chloramphenicol100449513
Cimetidine99379765
Ciprofloxacin95779192
Citalopram60.39213
Clarithromycin999510498
Clopidrogel9528628
Codeine100899978
Curcumin96489459
Cyclophosphamide90898576
Deracoxib7897720
Desipramine371496
Dexamethasone91679281
Dexmedetomidine9986908
Dextrometorphan6519030
Diazepam93328110
Diclofenac10113610171
Diethyldithiocarbamate93809565
Dopamine95469789
Doxepin8239036
Doxycycline97739888
Diphenhydramine8759037
Efavirenz122485210
Erythromycin948910092
Fenoprofen93619071
Fentanyl82128867
Firocoxib90449778
Fluconazole9714103
Flurbiprofen9414510299
Fluoxetine6228112
Furosemide90869685
Gabapentin1028810188
Hydromorphone89558878
Ibuprofen95818989
Imipramine4819381
Itraconazole87718463
Ketamine94456214
Ketoconazole4728419
Ketoprofen94839260
Ketorolac94899084
Ketotifen6328525
Lamotrigine925411081
Levomedetomidine360.2109
Lidocaine91509173
Lorazepam891610870
Maropitant718263
Meloxicam93839080
Methadone6728721
Metoclopramide10643105106
Metronidazole1059910679
Midazolam9156924
Morphine95859691
Mycophenolic acid906011779
Naproxen906511499
Norfloxacin96829887
Ofloxacin94829488
Omeprazole1052811257
Oxazepam923913978
Paroxetine2712011
Phenacetin854912479
Piperine847012676
Propofol93729122
Quinidine26210277
Quinine270.25712
Selegiline87509220
Suprofen95998587
Terbinafine91409963
Thio-TEPA991009890
Trazadone1033111054
Trifluoperazine3418825
Valproic Acid97999888
Vinblastine95219987
Xylazine93179741
Zomepirac96939577
  • Values in bold indicate more than 50% inhibition.