ST. JOHN'S WORT
St. John's wort may be the most widely used herbal
preparation currently on the market.
It is an extract prepared from a plant of the same name (Hypericum perforatum) that achieved recognition as an antidepressant following reports from Europe of clinical trials
showing that it improved mild
depression. Many people take St. John's wort to stave off depression or just to improve their state of mind. Most
research shows that St. John's wort
may have some effectiveness but not as much as pharmaceutical antidepressants, especially in cases of severe
depression.
So why not take a
little St. John's wort? By itself it isn't particularly dangerous. However, it has proved to have many
negative interactions with other
drugs, including some important medications. St. John's wort can stimulate the production of enzymes in the
liver that break down other drugs.
This allows the liver to break down some drugs so fast that a normal dose doesn't work. Birth control pills are
affected in this way, and there are cases in which women taking St. John's wort
have become pregnant because their
birth control pills were being degraded too quickly. Even more serious consequences have occurred. There
are more than ten case reports of transplant patients who experienced tissue
rejection when levels of their
immunosuppressant medication fell drastically after they started taking St. John's wort.
Finally, St. John's wort can interact dangerously
with one class of antidepressant, the serotonin-specific reuptake inhibitors
(SSRIs). Taking both St. John's wort and SSRIs can lead to “serotonin
syndrome" because serotonin is
inactivated more slowly than usual, resulting in higher-than-normal levels of serotonin in the synapses. At its mildest, people just feel flushed and jittery; at its worst,
it leads to an increase in body
temperature, heart rate, and blood pressure, and can be fatal.
