Q. My son has an anoxic brain injury and has ADHD as a result. He is 11 years old, 4' 7" and weighs 76 lbs. He takes Ritalin and Prozac. I am thinking of starting him on fish oil since I've heard many good things about it and brain injury. I also have been giving him a 400IU vitamin E capsule daily along with his regular Flintstones multi-vitamin. Will the fish oil interact with the Prozac? I've been told that it will concentrate the effects of the Prozac causing overdose reactions. I've researched and can't find anything to support this person's claim, but I'd rather be safe than sorry. Is this true?

A. Fish oil containing various types of omega fatty acids is being actively investigated as adjunctive treatment for a number of psychiatric conditions, including bipolar disorder, depression, and schizophrenia (see, for example, Peet et al, J Psychiatr Res 2002 Jan-Feb;36(1):7-18). So far, the early results are promising, and I am not aware of any significant interactions with standard medications for depression or schizophrenia.

Indeed, my own literature search turned up no reports of a specific interaction between fluoxetine [Prozac] and fish oil. However, I can't offer you any assurances of safety, since I doubt the question has been adequately studied. Moreover, there is one study looking at highly concentrated marine polyunsaturated fatty acids (n-3 PUFA)--basically, fish oil--in patients taking a medication called cyclosporine (see Busnach et al, J Nephrol 1998 Mar-Apr;11(2):87-93).

The fish oil did raise blood levels of cyclosporine, though apparently it did not lead to ill effects. Thus, it is conceivable that fish oil might raise blood levels of fluoxetine [Prozac] or Ritalin [methylphenidate] or both--but I am not aware of any published reports to that effect. (The blood levels of some formulations of methylphenidate, such as Metadate, may be affected by taking the drug with fatty foods--but it's not clear what effect fish oil would have if taken 2 hours before or after use of the medication). Even if we assume that fish oil did elevate levels of Prozac, there is no reason to assume that this would be bad.

There appears to be a fairly wide range of tolerable blood levels for the SSRIs, such as Prozac, and an increase in levels would not necessarily lead to any kind of toxic effects--though some people might experience more of the usual SSRI side effects, such as diarrhea. Blood levels of the Prozac and/or Ritalin could also be monitored, if necessary. But, all of these issues should be discussed with your son's doctor, the one who is prescribing the Ritalin and Prozac.

Even your use of vitamin E should be discussed with him or her. Bottom line--if you want to increase omega-3 fatty acids, a little tuna fish (once a week) will probably be beneficial in most individuals, and you don't have to worry about drug interactions!

January 2003

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