TMZ has learned that the former star of The OC was rushed to the hospital last night after suffering an adverse reaction to prescribed pills.
Sources say the pot smoker was at a friend's Memorial Day BBQ, enjoying a few holiday cocktails, when she began to feel ill.
Mischa, who had been quite sick with bronchitis since traveling to Cannes, London and Paris the past several weeks, didn't realize that you can't exactly mix alcohol with antibiotics.
But it's hard to thin blame the star: she so rarely puts anything in her mouth. How could she know? Well, unless friend and fellow fainter Nicole Richie had passed along such advice.
The 21-year-old was rushed to an undisclosed medical facility in Los Angeles, where insiders say she is "resting comfortably." Don't expect ex-boyfriend Cisco Adler to visit her any time soon, though.