Drug Groups

approved

Description

A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes smooth muscle, stimulates cardiac muscle, stimulates diuresis, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide phosphodiesterases, antagonism of adenosine receptors, and modulation of intracellular calcium handling. [PubChem]

Indication

For management of fatigue, orthostatic hypotension, and for the short term treatment of apnea of prematurity in infants.

Pharmacology

Caffeine, a naturally occurring xanthine derivative like theobromine and the bronchodilator theophylline, is used as a CNS stimulant, mild diuretic, and respiratory stimulant (in neonates with apnea of prematurity). Often combined with analgesics or with ergot alkaloids, caffeine is used to treat migraine and other headache types. Over the counter, caffeine is available to treat drowsiness or mild water-weight gain.

Toxicity

LD₅₀=127 mg/kg (orally in mice)

Affected Organisms

Biotransformation

Hepatic cytochrome P450 1A2 (CYP 1A2) is involved in caffeine biotransformation. About 80% of a dose of caffeine is metabolized to paraxanthine (1,7-dimethylxanthine), 10% to theobromine (3,7-dimethylxanthine), and 4% to theophylline (1,3-dimethylxanthine).

Absorption

Readily absorbed after oral or parenteral administration. The peak plasma level for caffeine range from 6-10mg/L and the mean time to reach peak concentration ranged from 30 minutes to 2 hours.

Half Life

3 to 7 hours in adults, 65 to 130 hours in neonates

Protein Binding

Low (25 to 36%).

Elimination

In young infants, the elimination of caffeine is much slower than that in adults due to immature hepatic and/or renal function.

Distribution

* 0.8 to 0.9 L/kg [infants]
* 0.6 L/kg [adults]

References

External Links