Table 2

Recorded pharmacokinetic data for caffeine

StudynDVd(p)ss ClFt ½U/P
Vickroy et al 24 63 mg/kg intravenously7602411.2
Greene et al 45 44 mg/kg intravenously6502418.263
44 mg/kg orally0.3942*3
Chou et al 46 23 mg/kg intravenously8203915.3
23 mg/kg intravenously78037.814.4
Peck et al 47 42.5 mg/kg intravenously131851
Aramaki et al 13 42.5 mg/kg intravenously85242.5†13.88†
42.5 mg/kg intramuscularly834
42.5 mg/kg orally8091.12†
Schumacher et al 48 10500 mg/horse (0.8–1.8 mg/kg) intravenously69442.710.18
Aramaki et al 49 42.5 mg/kg intravenously88740.415.5
52.5 mg/kg intramuscularly96536.618.6
42.5 mg/kg orally881391.0416.4
Todi et al 50 32 g/ horse orally3.16†
Kaiser51 64 mg/kg intravenously120971.616.1
64 mg/kg orally128.2*0.56
Machnik et al 21 64 mg/kg intravenously13455517.22
  • *Significant outlier.

  • †Calculated value.

  • Cl, clearance in ml/hour x kg; D, dose; F, bioavailability;n, number of animals.t ½, terminal half-life in hours; U/P, urine–plasma concentration ratio in the steady-state or pseudo-steady-state; Vd(p)ss, volume of distribution in ml/kg in the (pseudo)-steady state;