Measurement of caffeine and its three primary metabolites in human plasma by HPLC‐ESI‐MS/MS and clinical application

Abstract

Caffeine is a mild stimulant with significant potential for abuse being consumed in larger doses with the widespread availability of energy drinks and by novel routes of administration such as inspired powder, oral sprays, and electronic cigarettes. How these recent changes in caffeine consumption affecting caffeine disposition and abuse potential is of growing concern. In the study of caffeine disposition in humans, it is common to only measure the caffeine concentration; however, caffeine’s three major metabolites (paraxanthine, theobromine, and theophylline) retain central nervous system stimulant activity that may contribute to the overall pharmacological activity and toxicity. Therefore, it would be scientifically more rigorous to measure caffeine and its major metabolites in the evaluation of caffeine disposition in human subjects. Herein, we report a method for the simultaneous quantification of caffeine and its three major metabolites in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). Human plasma samples were treated by simple protein precipitation and the analytes were separated using a 6-min gradient program. Precision and accuracy were well within in the 15% acceptance range. The simple sample preparation, short runtime, sensitivity, and the inclusion of caffeine’s major metabolites make this assay methodology optimal for the study of caffeine’s pharmacokinetics and pharmacodynamics in human subjects.

Biomarker repurposing: Therapeutic drug monitoring of serum theophylline offers a potential diagnostic biomarker of Parkinson’s disease

“…We collected the samples after three-hour fasting, while there was no restriction of tea or coffee intake before sampling. Despite the weak influence of the caffeine load on serum theophylline levels [ 9 ], we cannot rule out the possibility that our data may have been affected by caffeine consumption directly prior to sampling. In the future, case-control studies involving sufficient numbers of participants with information on caffeine consumption as well as international quality control programs are needed to confirm our findings and promote the clinical application of this method.…”

“…First, measurements of serum theophylline levels have been commonly employed for therapeutic drug monitoring in patients with bronchial asthma and have already been adequately standardized to manufacture commercially available immunoassay kits. Second, serum levels of theophylline are less affected by caffeine intake compared with other primary caffeine metabolites, such as paraxanthine and theobromine [ 9 ]. Taken together, serum levels of theophylline represent caffeine metabolism without being affected by food intake; therefore, it can potentially serve as a blood-based biomarker of PD with acceptable inter-assay and inter-laboratory reproducibility.…”

Validation of an LC-MS/MS Method for the Quantification of Caffeine and Theobromine Using Non-Matched Matrix Calibration Curve

“…Chemically, caffeine (1,3,7-trimethylxanthine) is as methyl-xanthine, which is rapidly absorbed by the gastrointestinal tract and it is metabolized in the liver to form three major metabolites: 84% paraxanthine (1,7-dimethylxanthine), 12% theobromine (3,7-dimethylxanthine), and 4% theophylline (1,3-dimethylxanthine) [2,18,19]. There are some indications that theophylline and paraxanthine are more potent inhibitors of adenosine receptors than the parent caffeine [20,21].…”

Comparison of caffeine disposition following administration by oral solution (energy drink) and inspired powder (AeroShot) in human subjects

“…Details and validation of the assay used in this study are described in our previous publication . Briefly, an Agilent 1100 series liquid chromatography system (Waldbronn, Germany) was coupled to an AB SCIEX 3000 triple quadrupole mass spectrometer (Toronto, Canada).…”