TABLE 1.
NONTRICYCLIC ANTIDEPRESSANTS AND THEIR RISKS OF INTERACTION WITH WARFARIN
| Antidepressant | Potential Inhibition Effects on Cytochrome P-450 Isoenzymes* | Risk of Warfarin Interaction According to Lexi-Comp Online6 | Risk of Warfarin Interaction from Clinical Psychopharmacology1 | ||||
| 1A2 | 2C9/10 | 2C19 | 2D6 | 3A3/4 | |||
| SSRIs | |||||||
| Sertraline | -- | -- | -- | + | -- | C = monitor therapy | May ↑ PT(not clinically significance) |
| Citalopram/Escitalopram | -- | -- | -- | ++ | -- | C = monitor therapy | May ↑ PT (not clinically significant) |
| Paroxetine | -- | -- | -- | +++ | -- | C = monitor therapy | May ↑ bleeding |
| Fluvoxamine | +++ | +++ | +++ | -- | ++ | C = monitor therapy | May↑ INR |
| Fluoxetine | -- | ++ | ++ | +++ | + | C = monitor therapy | Avoid with warfarin |
| SNRIs | |||||||
| Venlafaxine | -- | -- | -- | -- | -- | No listing | May ↑ INR/PT |
| Duloxetine | -- | -- | -- | ++ | -- | D = consider therapy modification | -- |
| Other | |||||||
| Bupropion | unknown | unknown | unknown | +++ | unknown | No listing | May ↑ INR/PT |
| Mirtazapine | unknown | unknown | unknown | unknown | unknown | No listing | -- |
Key:
- -- =
no effect
- + =
mild effect
- ++ =
moderate effect
- +++ =
substantial effect
Note: Gray shaded areas under specific cytochrome P-450 isoenzymes represent the major routes of warfarin metabolism
- INR =
international normalized ratio
- PT =
prothrombin time
- SNRI =
serotontin norepinephrine reuptake inhibitor
- SSRI =
selective serotonin reuptake inhibitor