Copyright ©The Author(s) 2015.
World J Clin Pediatr. Nov 8, 2015; 4(4): 81-93
Published online Nov 8, 2015. doi: 10.5409/wjcp.v4.i4.81
Table 1 Pharmacokinetics of caffeine compared to theophylline
Mechanism of action:
CNS stimulationMore activeLess active
Cardiac stimulationLess activeMore active
DiuresisLess activeMore active
Loading dose20 to 40 mg/kg per dose IV/PO4 to 8 mg/kg per dose IV
Maintenance dose5 to 8 mg/kg per dose once daily IV/PO1.5 to 3 mg/kg per dose every 8 to 12 h IV
Plasma half-life (h)40 to 230 (mean, 103)12 to 64 (mean, 30)
Therapeutic level (mg/L)5 to 257 to 12
Toxic level (mg/L)> 40 to 50> 20
Adverse effects:
CardiovascularTachycardia, dysrhythmiaTachycardia, dysrhythmia
GastrointestinalFeeding intolerance, GERFeeding intolerance, GER
CNSJitteriness, irritability, seizuresJitteriness, irritability, seizures, decreased CBF
Signs of toxicityTachycardia, cardiac failure, pulmonary edema, hypertonia, sweating, metabolic disturbancesTachycardia, agitation, hypokalemia, diuresis, gastric bleeding, seizure
MetabolismExcreted unchanged or N-demethylation via CYP P450 (CYP1A2) liver-methyltransferase pathwayExcreted unchanged or undergoes 8-hydroxylation via CYP1A2 and CYP2E1
Inter-conversion3% to 8% converted to theophylline via CYP1A225% converted to caffeine via methylation
Routine blood levelNot requiredRequired
Elimination86% unchanged in urine50% unchanged in urine
CSF levelSimilar to plasma concentrationsCrosses into the CSF
Clearance (L/kg per hour)[9,43]0.002 to 0.0170.02 to 0.05