Caffeine drug interaction

Several factors predispose to lithium toxicity, including sodium restriction, dehydration, vomiting, diarrhea, drug interactions that decrease lithium clearance, heavy exercise, sauna baths, hot weather, and fever. Patients should be told to maintain adequate sodium and fluid intake and to avoid excessive coffee, tea, cola, and other caffeine-containing beverages and alcohol. 

An example of a potentially important drug interaction is that which occurs when fluvoxamine is given along with theophyllin (Figure 6—13). In that case, the theo-phyllin dose must be lowered or else the blood levels of theophyllin will rise and possibly cause side effects, even toxic side effects such as seizures. The same may occur with caffeine. Fluvoxamine also affects the metabolism of atypical anti-psychotics. 

Drug interactions The effect of antacids and cations on the absorption of these agents was considered above. Ciprofloxacin, ofloxacin and enoxacin can increase the serum levels of theophylline by inhibiting its metabolism. They also may raise levels of warfarin, caffeine and cyclosporine. Cimetidine interferes with the... 

Donovan JL, DeVane CL. A primer on caffeine pharmacology and its drug interactions in clinical psychopharmacology. Psychopharmacol Bull 2001 35(3) 30-48. 

Eap CB, Bondolfi G, Zullino D, Bryois C, Fuciec M, Savary L, Jonzier-Perey M, Baumann P. Pharmacokinetic drug interaction potential of risperidone with cytochrome p450 isozymes as assessed by the dextromethorphan, the caffeine, and the mephenytoin test. Ther Drug Monit 2001 23(3) 228-31. 

At least 40 drugs interact with caffeine, including benzodiazepines (for example diazepam, whose sedative effect is counteracted by caffeine) (40). 

Because caffeine, nicotine, and alcohol are used by many people in some combination, knowing how each of these drugs interacts with the other two is important. 

There are theoretical drug interactions with caffeine and monoamine oxidase inhibitors. Caffeine could increase risk of cardiovascular events when taken with C. aurantium (54). The case report of MI (45) and several of the Canadian reported adverse events included caffeine (46). Synephrine, tyramine, and octopamine are all substrates of monoamine oxidase (55). Taking a monoamine oxidase inhibitor with C. aurantium could increase concentrations of these sympathomimetics, and thus should be avoided. 

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