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voriconazole, and other medications. This may require adjustments to maintain an
effective dose.
The Natural Standard advises caution if benzodiazepine tranquilizers, opioids, or P-
glycoprotein regulated drugs are taken with St. John’s wort.
- SIDE EFFECTS
Brown et al. conclude that: “Our view of data from 35 double-blind randomized trials
found that dropout and adverse effects for patients receiving St. John’s wort were
similar to placebo, lower than with older antidepressants, and slightly lower than with
SSRIs.”^22
In Brown et al II, Sarris concluded more broadly, based on a review of 16 post-marketing
studies (34,834 subjects), that St. John’s wort is “ten-fold safer than synthetic
antidepressants.”^23
However, it must be kept in mind that clinical trials often do not include patients with
co-existing medical or psychiatric disorders who may be on other medications. In real
life clinical practice, many people are taking additional medications for co-morbid
medical conditions. Therefore, one cannot always generalize the findings from even a
randomized study to the potential risks to patients being treated outside of a research
trial.
Generally, Mischoulon and Rosenbaum report, use of St. John’s wort by itself creates
few dangers, and adverse events are relatively "uncommon and mild” for persons who
are screened under the above criteria of risk, somewhat similar but milder than SSRIs.
The Natural Standard states that St. John’s wort is generally well tolerated for up to
three months. The most common adverse effects include gastrointestinal upset, skin
reactions, fatigue/sedation, restlessness or anxiety, sexual dysfunction, dizziness,
headache, and dry mouth. Studies suggest that side effects occur in 1 to 3% of patients
and that this percentage is similar to placebo (and less than standard antidepressant
drugs). 24
