Pharmacokinetics of Caffeine following a Single Administration of Coffee Enema versus Oral Coffee Consumption in Healthy Male Subjects

Table 1

Pharmacokinetic parameters of caffeine following a single administration of the coffee enema or the oral coffee consumption (𝑛=11).

Parameters	Coffee procedure				95% confidence; interval of the difference		𝑃 value*
	Coffee enema	Oral coffee consumption	Mean difference	Standard error difference	Lower	Upper
𝐶max  (μg/mL)	0.77±0.14	2.47±0.39	−1.70	0.12	−1.96	−1.44	<0.001
AUC0−12  (μg·h/mL)	3.69±0.95	13.05±2.06	−9.36	0.71	−10.83	−7.89	<0.001
AUC0−∞  (μg·h/mL)	4.73±1.74	16.32±3.89	−11.59	1.28	−14.27	−8.84	<0.001
𝑇max (h)	0.30±0.12	0.44±0.11	−0.14	0.05	−0.24	−0.02	0.02
𝑡1/2 (h)	4.68±1.36	4.87±1.39	−0.19	0.59	−1.41	1.04	0.76

Data represents mean ± SD. Abbreviations: 𝐶_max: maximum plasma caffeine concentrations, AUC₀₋₁₂: area under the concentration-time curve from administration to 12 hours, AUC_0−∞: area under the concentration-time curve from administration and extrapolation to infinity, 𝑇_max: time to reach maximum plasma concentration, and 𝑡_1/2: half-life. *Statistical analysis using paired Student’s 𝑡-test.