Drug and Herb Interaction
Natural supplements can sometimes interfere with the efficacy of prescription drugs, and the opposite is also true, as we see in this question from a reader named Karen: "My husband's Psychiatrist told him that Prozac affects the liver's ability to utilize herbal medicines such as saw palmetto. He had never heard this before and wasn't able to find anything on the web to corroborate this. Have there been any studies that would prove that statement?" I asked one of our panelist, Allan Spreen, M.D., to help me field this one, and here's his response to Karen: "I'm not familiar with this particular side effect of Prozac. However, bear in mind that Prozac works specifically by enzyme BLOCKING for increased serotonin levels, officially called '...inhibition of CNS neuronal uptake of serotonin' in Physicians' Desk Reference (2002, p.1238). "Nutrient therapies work by promoting the body's ability to produce a desired end result, either by supplying more of the raw materials required, enhancing the enzymes that produce the desired reaction, etc. Drug therapies must block activity of some sort, since they are 'designer' agents created to force a result (unfortunately, blocking something usually impinges on something else that's undesired). If they merely supplied or enhanced a normal situation then they'd be using a mechanism natural to the body, and subsequently the reaction is no longer patentable (read that 'profitable'). "For that reason I'd have no problem believing that inhibition of other natural processes, in addition to the desired one, could easily occur. "Either way, all you need to know to be afraid of Prozac is a partial list of the published KNOWN side effects, admitted to by the manufacturer (only ones labeled as 'frequent' are listed): '...chills...hemorrhage, hypertension...nausea and vomiting...weight gain...agitation, amnesia, confusion, emotional lability, sleep disorder...ear pain, taste perversion, tinnitus...urinary frequency...' (Ibid.) Listing the 'infrequent' side effects would increase the list to positively boring proportions (from five- to ten-fold). "So (though having no proof) yes, I could easily believe the drug could interfere with natural processes."