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St. John's wort is POSSIBLY UNSAFE when taken by mouth during pregnancy. There is some
evidence that it can cause birth defects in unborn rats. No one yet knows whether it has the same
effect in unborn humans.
Photosensitivity reactions; Avoid exposure to sunlight or tanning beds. St. John's wort can make
you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when
you are outdoors.
Avoid taking St. John's wort with other medicines that can make you more sensitive to sunlight,
especially antibiotic medicine or a sulfa drug.

Drug Interactions:

MAO inhibitor: St. John's Wort contains some weak monoamine oxidase inhibitor (MAOI)
properties that may add to the effects of other MAOI drugs, therefore theoretically increasing
the risk for hypertensive crisis.
Beta-sympathomimetic amines: It is prudent to avoid concomitant use with
betasympathomimetic amines, e.g., ma huang or pseudoephedrine.
SSRIs (Fluoxetine): together with St. John's wort (has SSRI activity) can increase the risk of a rare
but serious condition called the serotonin syndrome, which may include symptoms such as
confusion, hallucination, seizure, extreme changes in blood pressure, increased heart rate, fever,
excessive sweating, shivering or shaking, blurred vision, muscle spasm or stiffness, tremor,
incoordination, stomach cramp, nausea, vomiting, and diarrhea. Severe cases may result in coma
and even death.
Triptans (sumatriptan, naratriptan, rizatriptan, zolmitriptan): Potentiation of serotonin
concentration.
Medications changed by the liver (Cytochrome P450 substrates: Some medications are changed
and broken down by the liver. St. John's wort might increase how quickly the liver breaks down
some medications. Taking St. John's wort along with some medications that are broken down by
the liver can decrease the effectiveness of your medication.

• Cyclosporine: St. John's Wort has been proven to induce the cytochrome P450 enzyme
system, the major pathway for cyclosporine metabolism. Heart transplant rejection has
been reported as soon as 3 weeks after St. John's Wort is added to the drug regimen of

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