Pharmacokinetics of caffeine self-administered in overdose in a Japanese patient admitted to hospital

Background Caffeine (0.1 g) is used as a central nervous system stimulant and as a nontoxic phenotyping probe for cytochrome P450 1A2. However, an increasing number of suicide attempts by caffeine overdose have been recently reported. Case presentation A 25-year-old woman (body weight, 43 kg) who intentionally took an overdose of 5.9 g caffeine as a suicide attempt was emergently admitted to Kyoto Medical Center. The plasma concentrations of caffeine and its primary metabolite, N-demethylated paraxanthine, in the current case were 100 and 7.3 μg/mL, 81 and 9.9 μg/mL, 63 and 12 μg/mL, and 21 and 14 μg/mL, at 12, 20, 30, and 56 h after oral overdose, respectively. The observed apparent terminal elimination half-life of caffeine during days 1 and 2 of hospitalization was 27 h, which is several times longer than the reported normal value. This finding implied nonlinearity of caffeine pharmacokinetics over such a wide dose range, which could affect the accuracy of values simulated by a simplified physiologically based pharmacokinetic model founded on a normal dose of 100 mg. Low serum potassium levels (2.9 and 3.5 mM) on days 1 and 2 may have been caused by the caffeine overdose in the current case. Conclusions The patient underwent infusion with bicarbonate Ringer’s solution and potassium chloride and was discharged on the third day of hospitalization despite taking a potentially lethal dose of caffeine. The virtual plasma exposures of caffeine estimated using the current simplified PBPK model were higher than the measured values. The present results based on drug monitoring data and additional pharmacokinetic predictions could serve as a useful guide in cases of caffeine overdose.

Review Effect of Caffeine Overdose

Background: Caffeine is from methyl xanthine class which mainly stimulates the central nervous system. Caffeine is one of the most widely used psychoactive drugs in the world. It is commonly found in beverages, chocolates, cocoa containing products and in medications. Caffeine is recognized as legal and its consumption is unregulated all over of the world. Objectives: The objective of this study is to summarize the impact of caffeine on behavioral and health alterations, in both controlled and overdose conditions. Moreover, the specifics of caffeine withdrawal and a number of guidelines on how to handle reducing or quitting caffeine intake altogether is also highlighted. Methodology: To compose this review, more than seventy research and review articles were overviewed that were published over a period of last twenty years, using Google Scholar search engines. Results: Caffeine regular use causes physical dependence which may become the caffeine withdrawal sign that can consequently harm normal working. The most important function of caffeine is that it can reversibly blocks the adenosine performance on its receptor and as a result which prevent the beginning of drowsiness encouraged by adenosine. Caffeine also stimulates certain portions of the autonomic nervous system symptom including fatigue, drowsiness, depressed mood, headache, difficulty concentrating, decreased energy, decreased contentedness, decreased alertness, irritability and unclear headed. Conclusion: It is concluded that utilization of caffeine in a prescribed dose can have good impact on health and may decrease addictive symptoms. Additionally, reducing caffeine dosage over a six week period guides to successful, long-term caffeine cessation with very few side effects.

Suicidal attempt with caffeine overdose treated with dexmedetomidine: a case report

Background Caffeine is a widely used dietary stimulant, and cases of caffeine overdoses, sometimes leading to death, are increasing. We encountered a case of caffeine intoxication resolved with administration of the sedative agent dexmedetomidine. Case presentation We administered dexmedetomidine for sedation and to suppress sympathetic nerve stimulation in the case of an 18-year-old Japanese male who ingested a massive dose of caffeine with the intention of committing suicide. The patient was in an excited state and had hypertension, sinus tachycardia, and hypokalemia with prominent QT prolongation. After dexmedetomidine administration, the patient’s mental state, hemodynamics, and electrolyte levels were improved immediately. He was discharged without any sequelae 3 days later. Conclusion Cases of acute caffeine intoxication with agitation, sympathetic overactivity and adverse cardiac events would benefit with dexmedetomidine treatment.