St. John’s Wort (Hypericum perforatum)

Many lay people believe that natural = safer and better, but that’s not necessarily true.

What does it do?

It is a combo of a lot of different ingredients; therefore the concentration of active compounds in the drug is very variable. So, until we know what the active ingredient is, it is very difficult to get a standardized preparation with equivalent potency ==> wide degree of variation.

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The mechanism of action behind St. John’s wort is still unclear; some people say that it works via hypericin and/or hyperforin.

-Low amounts of MAOI activity

-GABAergic activity

-May inhibit uptake of 5-HT, NE, and dopamine, but not to the degree of regular antidepressants

such as TCAs or SSRIs.

It must be doing something though, bc its side effects include the following:

-Dry mouth, GI complaints, dizziness, confusion

-At least three reports of moderate serotonergic crises ==> fevers, confusion, shaking

-Several reports of induced mania, like all of the other antidepressants

-Severe phototoxicity reported in animals and at least one clinical report

-Potential for drug interactions

Also, the standardization of preparation is poor; pills in the same bottle can contain different concentrations of active ingredients ==> toxicity or lack of efficacy.

Category: Pharmacology Notes