Cyanide and venlafaxine

Nine years ago, on January 3 an 18 yo man in Maryland killed his best friend.  It reads like a story of teenage angst.  Teen falls for best friend's girl friend.  Teen feels neglected by his best friend.  Teen then plans, and carries out, an elaborate plan to murder his friend.  Just another teenage friendship gone awry 

It is the behind the scenes story that makes this even more interesting.  18 yo Ryan Furlough decided months before that his friend would have to go.  He carefully researched how to murder, and poisoning was the method of choice.  He then researched what the best substance would be and decided cyanide.  In his research he found the appropriate dose and information on how to deliver it.  Finally he used his mother's credit card to order the cyanide on-line.  On January 3 he invited his friend over to the house for some video games.  While playing he added the cyanide to his friend's Vanilla Coke.  Moments later the cyanide took effect and four days later the best friend died. 

Cyanide is a substance with a long history for poisoning.  It was used in the Tylenol poisonings in Chicago.  Then again by the "Candy Man" in Houston.  Cyanide was used to murder millions by the Nazis.  Google search cyanide murders and you will get thousands of hits.

But there is more. It seems Ryan Furlough was being treated for depression.  In the months prior to this murder his treatment was changed from fluoxetine to venlafaxine.  As you could gather from the above Ryan left an extensive trail clearly showing that he planned his friend's death.  He also confessed to police that he murdered him.  His defense was that he was taking venlafaxine.  The black box warning for venlafaxine talks about suicidal thinking and behavior.  It is not much of a stretch to go beyond suicide to other impulsive behaviors.  So, was Ryan unduly under the influence of his antidepressant?  Did the venlafaxine make him act out and poison his friend?  The jury said no and found him guilty of murder.