Question

A 16-year-old girl is brought to the clinic by her mother who expresses concern regarding her daughter's growing caffeine dependence for the past four months. She explains that her daughter drinks four to five cups of coffee and invariable caffeinated sodas throughout the day. Her concern stems from her daughter's progressively aggravating moodiness, irritability, gastrointestinal disturbances, and sleeping difficulties that are disturbing her personal and social life. The patient seems restless and frustrated, acknowledging her mother's concerns and the harm posed by excess caffeine use, but refuses to cut back on her intake, expressing fear of withdrawal symptoms which are 'unacceptable' to the patient. Which active metabolite is responsible for the psychostimulant effect of caffeine?

A. Theobromine
B. Theophylline
C. Methyluric acid
D. Paraxanthines
E. 1,3,7-Trimethyluric acid

Answer 1

The active metabolite responsible for the psychostimulant effect of caffeine is caffeine itself, as it acts as an antagonist of adenosine receptors and not its metabolites. Neither Theobromine, Theophylline, Methyluric acid, Paraxanthines, nor 1,3,7-Trimethyluric acid are primarily responsible for these effects of caffeine.

Step-by-step explanation:

The psychostimulant effect of caffeine is primarily due to its action as an antagonist of adenosine receptors. However, the active metabolite responsible for this psychostimulant effect of caffeine is not listed among the options provided in the question (A. Theobromine, B. Theophylline, C. Methyluric acid, D. Paraxanthines, E. 1,3,7-Trimethyluric acid). In general, caffeine itself, rather than its metabolites, is known to exert the central nervous system (CNS) stimulating effects by blocking the adenosine receptors. Caffeine increases levels of alertness and arousal and may have some indirect effects on dopamine neurotransmission. For educational purposes, the most appropriate answer relating to caffeine's psychostimulant effect itself, rather than its metabolites, would be 'Caffeine', which is the parent compound. If required to choose from the provided options, it would be more accurate to ask which metabolite has mild CNS stimulating effects, in which case Theobromine (A) or Theophylline (B) could be considered, but they are not primarily responsible for the psychostimulant effects associated with caffeine consumption.