St. John's Wort

St. John's Wort

• St. John's wort (Hypericum perforatum) is a yellow plant that is native to Europe and Asia and has been used there for centuries. It works mainly as a serotonin reup-take inhibitor, but can also inhibit the reuptake of dopamine and norepinephrine. It does this by activating the cytochrome P450 system, specifically CYP3A4 and monooxygenase enzymes. The main compounds in St. John's Wort that have this mechanism are hypericin and hyperforin.

Dosage:

• The usual dosage for St. John's wort with 0.3% hypericin or 5% hyperforin is 300 mg orally BID or TID (total daily dose of 600-900 mg) or topically. The main uses for St. John's wort are listed below:

• Depression: St. John's wort works similarly to SSRIs with the mechanism for the treatment of depression. Meta-analysis and individual trials have compared St. John's wort to placebo as well as other anti-depressant medications.

• It has shown to improve depression symptoms for patients. Some studies mentioned that some participants tolerated St. John's wort better than SSRIs. However, other studies have shown that it was no more effec-tive than placebo. Severe forms of depression should not be treated with St. John's wort.

• Somatoform disorders: There is some data that St. John's wort can be used to improve symptoms of somatoform disorders compared to placebo.

• However, some of the studies did not follow patients for a prolonged period of time and did not include data on adverse side effects.

• St. John's wort may be beneficial with symptoms relating to premenstrual cravings, cramping and irritability, menopausal symptoms such as hot flashes, seasonal affective disorder, obsessive compulsive disorder, and eczema

Safety Concerns:

• The most concerning safety concerns are regarding the interactions St. John's wort has with other commonly used medications (as discussed below).

• Common side effects reported if St. John's wort is taken alone include dizziness, anxiety, fatigue, diarrhea, photosensitivity, and dry mouth. It is contra-indicated in pregnancy and lactation.

Interactions:

• St. John's wort interacts with many common prescription medications due to its proposed mechanism of action. It can reduce the effectiveness of the medications listed below:

• Allergy medications: Loratadine, Fexofenadine, Cetirizine; Antidepressants: SSRIS, TCAS, MAO inhibitors, Nefazodone; Birth control pills, Clopidogrel, Coumadin, Cyclosporine, Digoxin, HIV medications including protease inhibitors and non-nucleoside reverse transcriptase inhibitors: Immunosuppressant medications such as Adalimumab (Humira). Statins, Triptans, Warfarin.