theophylline and St John's wort
Last reviewed 01/2018
St John's wort (SJW) interacts with theophylline and may cause reduced theophylline levels.
Suggested management of patients already taking SJW preparations:
- check theophylline levels and stop SJW
- note that there may be an increase in theophylline levels on stopping SJW
- it may be necessary to adjust the theophylline dose