| Carbamazepine (Tegretol) | May increase toxic effects of CNS depressants* |
| May decrease effectiveness of CYP1A2 substrates†, CYP2B6 substrates‡, CYP2C9 substrates, CYP3A4 substrates||, oral contraceptives, thyroid medications, and TCAs | |
| Effects can be decreased by CYP3A4 inducers | |
| Toxic effects can be increased by CNS depressants* and SSRIs | |
| Absolutely contraindicated with MAOIs | |
| Duloxetine (Cymbalta) | May increase toxic effects of CNS depressants*, |
| SSRIs, and warfarin (Coumadin) | |
| May decrease effectiveness of TCAs | |
| Effects can be decreased by CYP1A2 inducers** | |
| Toxic effects can be increased by CNS depressants* and SSRIs | |
| Absolutely contraindicated with MAOIs | |
| Oxycodone, controlled release (Oxycontin) and morphine | May increase toxic effects of CNS depressants*, MAOIs, and SSRIs |
| Effects can be decreased by CYP3A4 inducers¶ | |
| Toxic effects can be increased by CNS depressants* | |
| Pregabalin (Lyrica) and gabapentin (Neurontin) | May increase toxic effects of CNS depressants* |
| Toxic effects can be increased by CNS depressants* | |
| Tramadol (Ultram) | May increase toxic effects of CNS depressants* and SSRIs |
| Toxic effects can be increased by CNS depressants*, SSRIs, and TCAs | |
| TCAs | May increase toxic effects of CNS depressants*, QTc-prolonging agents††, SSRIs, St. John’s wort, sulfonylureas, tramadol, and warfarin |
| Effects can be decreased by carbamazepine and St. John’s wort | |
| Toxic effects can be increased by CNS depressants*, duloxetine, QTc-prolonging agents††, SSRIs, and St. John’s wort | |
| Absolutely contraindicated with MAOIs | |
| Venlafaxine (Effexor) | May increase toxic effects of CNS depressants* and SSRIs |
| Effects can be decreased by CYP3A4 inducers¶ | |
| Toxic effects can be increased by CNS depressants*, CYP2D6 inhibitors‡‡, CYP3A4 inhibitors§§, and SSRIs | |
| Absolutely contraindicated with MAOIs |