Theophylline (a caffeine analog in tea) interacts with lithium
Quote:...Studied the effect of steady-state therapeutic theophylline serum levels on lithium renal clearance in 10 healthy 20–37 yr old volunteers. Data support a significant increase in renal lithium clearance with a resultant lowering of serum lithium levels when theophylline is added to established lithium therapy...
Quote:Objective: To review current methods, well documented and investigational, being used to decrease lithium absorption or enhance lithium elimination.... Saline or forced diuresis is not effective in enhancing lithium elimination unless the patient is volume or sodium depleted.... Intravenous aminophylline (theophylline) is not consistently effective and its risks outweigh possible benefits....
So theophylline enhances lithium clearance, apparently in a variable or unreliable way, independent of its diuretic effect.
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