Acute guarana poisoning: report of two cases

Guarana (Paullinia cupana) is a South American plant that contains twice more caffeine compared to coffee beans, and has a stimulatory effect. Thus guarana preparations in the form of capsules, tablets, powders, teas, syrups and energy drinks contain a lot of caffeine, which can rapidly cause poisoning even when only slightly overdosed. Caffeine poisoning may result in irritability, insomnia, anxiety, restlessness, muscle twitching, nausea or vomiting, rapid heart beat or cardiac arrhythmias, high blood pressure, sweating, diuresis and gastroinestinal disturbance. This report presents two cases of guarana overdose with the common caffeine poisoning symptoms and signs. Guarana in therapeutic doses can exacerbate underlying cardiac disease (especially cardiac arrhythmias, coronary heart disease, heart failure) and diabetes. Furthermore, children, pregnant and nursing women should avoid guarana as well. Treatment of guarana poisoning is symptomatic, mainly with benzodiazepines and by fluid and electrolyte substitution