Interactions of St John's Wort

The CSM has advised that St John's Wort should not be used with:

• indinavir
• warfarin
• cyclosporin
• oral contraceptives
• theophylline
• digoxin

Although there is no direct evidence, it is likely that clinically important interactions may occur with:

• other HIV protease inhibitors (saquinavir, nelfinavir ritonavir)
• HIV non-nucleoside reverse transcriptase inhibitors (nevirapine, efavirnez)
• anticonvulsants (phenobarbitone, phenytoin, carbamazepine)

Additionally St John's Wort:

• may interact with selective serotonin reuptake inhibitors
• may have pharmacodynamic interactions with the triptans used to treat migraine

Reference:

• CEM/CMO/2000/4