Drug Groups

approved; investigational

Description

A central nervous system stimulant used most commonly in the treatment of attention-deficit disorders in children and for narcolepsy. Its mechanisms appear to be similar to those of dextroamphetamine. [PubChem]

Indication

For use as an integral part of a total treatment program which typically includes other remedial measures (psychological, educational, social) for a stabilizing effect in children with a behavioral syndrome characterized by the following group of developmentally inappropriate symptoms: moderate-to-severe distractibility, short attention span, hyperactivity, emotional lability, and impulsivity.

Pharmacology

Methylphenidate is a central nervous system stimulant used most commonly in the treatment of attention-deficit disorders in children and for narcolepsy. Its mechanisms appear to be similar to those of dextroamphetamine.

Toxicity

Symptoms of overdose include vomiting, agitation, tremors, hyperreflexia, muscle twitching, convulsions (may be followed by coma), euphoria, confusion, hallucinations, delirium, sweating, flushing, headache, hyperpyrexia, tachycardia, palpitations, cardiac arrhythmias, hypertension, mydriasis, and dryness of mucous membranes. LD₅₀=190mg/kg (orally in mice)

Affected Organisms

Biotransformation

Hepatic, methylphenidate is metabolized primarily by de-esterification to ritalinic acid (α-phenyl-2-piperidine acetic acid, PPAA), which has little to no pharmacologic activity.

Absorption

Readily absorbed in a biphasic manner. It reaches peak absorption at approximately two hours for the first phase and five hours for the second phase. Bioavailability is low (approximately 30%)

Half Life

2.4 hours in children and 2.1 hours in adults

Protein Binding

Low (approximately 15%)

References

External Links