in the new york times there was a good analysis of the “nocebo effect”–people on placebo in various studies who have significant side-effects. can be up to the 40% range. an example of a patient who attempted suicide by taking an overdose of meds, which, unbeknownst to him, was placebo — and his blood pressure dropped!! other studies suggest that when provider describes potential side-effects of a new med, there is a greater likelihood of the patient developing that side-effect. see: http://www.nytimes.com/2012/08/12/opinion/sunday/beware-the-nocebo-effect.html?_r=1
in my practice, i mention common side-effects but more in a dismissive way (like, “although some people may develop some inflammation of the liver when on a statin, it is really unlikely, i have seen it rarely in the many patients i have on statins, and i will monitor you closely just in case”), especially if i think the med in question is really important for the patient. however, i have had several patients who refuse to take the med after reading the attached pharmacy paper detailing the side-effects. so, my sense is that we do need to mention important side-effects to new med, we need to make sure that we put this in perspective and that the patient understands our rationale for prescribing the med and then reassure the pt that we will be accessible and will follow them closely to make sure all is ok (also does reinforce utility of seeing the patient sooner than later after starting a new and important med, to make sure there is no problem).
geoff