API UseInventoryItem

Use an item in a specific inventory slot.
===Syntax===
 UseInventoryItem( slotID )
===Arguments===
:;slotID:The inventory slot ID
:You can get the slot ID by using GetInventorySlotInfo(slot)
===Return Value===
Always nil.
===Example===
:/script UseInventoryItem( GetInventorySlotInfo("Trinket0Slot") );
After patch 1.6 you cant auto-use items anymore. Addons can no longer activate items without the press of a button. In order to use UseInventoryItem( GetInventorySlotInfo("Trinket0Slot") ) you will have to call it from a button, keypress or icon as you do with spells.