| Item |
Information |
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Drug Groups
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approved; investigational |
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Description
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Modafinil is a stimulant drug marketed as a 'wakefulness promoting agent' and is one of the stimulants used in the treatment of narcolepsy. Narcolepsy is caused by dysfunction of a family of wakefulness-promoting and sleep-suppressing peptides, the orexins, whose neurons are activated by modafinil. The prexin neuron activation is associated with psychoactivation and euphoria. The exact mechanism of action is unclear, although in vitro studies have shown it to inhibit the reuptake of dopamine by binding to the dopamine reuptake pump, and lead to an increase in extracellular dopamine. Modafinil activates glutamatergic circuits while inhibiting GABA. |
| Indication |
To improve wakefulness in patients with excessive daytime sleepiness (EDS) associated with narcolepsy. |
| Pharmacology |
Modafinil is a stimulant drug marketed as a 'wakefulness promoting agent' and is one of the stimulants used in the treatment of narcolepsy. Narcolepsy is caused by dysfunction of a family of wakefulness-promoting and sleep-suppressing peptides, the orexins, whose neurons are activated by modafinil. The prexin neuron activation is associated with psychoactivation and euphoria. Modafinil is not indicated for complaints of lack of energy or fatigue; but it appears to be very helpful for some patients. Also, it has been used in the treatment of hypersomnia, a disorder in which patients lack the capacity for meaningful sleep and may require ten or more hours per day. Recent studies have have found that modafinil may help recovering cocaine addicts fight their addiction. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Hepatic |
| Absorption |
Rapid following oral administration. |
| Half Life |
23-215 hours |
| Protein Binding |
60% |
| Elimination |
The major route of elimination is metabolism (~90%), primarily by the liver, with subsequent renal elimination of the metabolites. |
| Distribution |
* 0.9 L/kg |
| References |
| • |
Lindsay SE, Gudelsky GA, Heaton PC: Use of modafinil for the treatment of attention deficit/hyperactivity disorder. Ann Pharmacother. 2006 Oct;40(10):1829-33. Epub 2006 Sep 5.
[Pubmed]
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| • |
Ishizuka T, Sakamoto Y, Sakurai T, Yamatodani A: Modafinil increases histamine release in the anterior hypothalamus of rats. Neurosci Lett. 2003 Mar 20;339(2):143-6.
[Pubmed]
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| External Links |
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