Chronic pain is often associated with depression and many herbal over-the-counter remedies for self-treatment of depression or anxiety contain St. John’s wort. New research suggests that taking this herbal product can incur drug interactions that may reduce effects of oxycodone and many other opioid analgesics.Researchers in Finland designed a randomized, placebo-controlled, cross-over trial in which 12 healthy subjects were administered either St. John’s wort or placebo three-times daily for 15 days and given oral oxycodone hydrochloride 15 mg on day 14 [Nieminen et al. 2010]. Following St. John’s wort administration oxycodone plasma concentration was significantly decreased by 50% and its half-life was shortened by 27%, resulting in the self-reported drug effects of oxycodone decreasing significantly (p=0.004). The authors conclude that this interaction of St. John’s wort and oxycodone could be of clinical significance when treating patients with chronic pain.











