Corrected entry: Hannibal says "I ate his liver with some fava beans and a nice chianti." He could get treatment with drugs called monoamine oxidase inhibitors - MAOIs, which he'd know, being a psychiatrist. However there are things you can't eat when taking MAOIs (potentially fatal), including liver, beans, and wine (also aged cheeses, if you're interested). So he's subtly letting on that he's not taking his medication, through the medium of a joke for his own amusement.
Jon Sandys
13th Feb 2015
Correction: Psychopaths cannot be treated with medication and MAOIs are used for depression. Hannibal couldn't be treated even with antipsychotics or a mood stabiliser because antisocial personality disorder can't be medicated, and he would not be taking medications for his psychopathy regardless, because psychopaths have no remorse for their actions, so he wouldn't treat something he does not believe to be a problem.