Lexorin
Lexorin was a drug utilized during the late 23rd century. 

It was able to alleviate symptoms of malaise and/or multiple personality disorder in those who experienced a Vulcan mind meld, or who carried a Vulcan katra prior to its placement on Mount Seleya. 

In 2285, James T. Kirk administered a dose of lexorin to Leonard McCoy to help him feel well enough to travel with Spock's katra to . ()

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Drugs