There is an old drug that has fairly recently been shown to prevent the emotional consequences of memory Recall via reconsolidation.   

The drug is Propranolol, a beta blocker that prevents adrenergic stimulation.  Marketed as Inderal, this medication has long been prescribed to control high blood pressure and anxiety. 

Among the fascinating implications, Propranolol administration during the recall of painful memories may speed the habituation(healing) of past traumas, and help abolish chemical addiction.