modafinil (Provigil)

Modafinil is an oral drug that is used for improving wakefulness in patients with excessive sleepiness. It is similar to armodafinil (Nuvigil). Like amphetamines, modafinil promotes wakefulness by stimulatIng the brain. The exact mechanism of action of modafinil is unknown. It may work by increasing the amount of dopamine (a chemical neurotransmitter that nerves use to communicate with each other) in the brain by reducing the reuptake of dopamine into nerves. Modafinil was approved by the FDA in December 1998.

Provigil

GENERIC AVAILABLE: Yes

Yes

The most common side effects of modafinil include:

• headache,
• upper respiratory tract infection,
• nausea,
• nervousness,
• anxiety, and
• insomnia.

Modafinil is used to promote wakefulness in patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea (in addition to treatment of the underlying obstruction), and shift work sleep disorder. Narcolepsy is a chronic disease of the brain and spinal cord characterized most commonly by a recurrent, uncontrollable desire to sleep. Shift work sleep disorder is a condition in which the normal rhythm of sleep is disturbed, often as a result of working at night. Sleep apnea is a condition where sleep is constantly interrupted at night because of pauses in breathing or shallow breathing usually due to obstruction of the upper airway.

The recommended dose is 200 mg once daily not to exceed 400 mg. It should be administered in the morning for treating narcolepsy or obstructive sleep apnea, and one hour prior to work in those with shift work disorder. It can be taken with or without food. The 400 mg dose may not be more effective than the 200 mg dose.

Modafinil can decrease or increase the activity of enzymes in the liver that metabolize (eliminate) other drugs. This can result in decreased levels of some drugs that reduce their effectiveness and increased levels of other drugs that leads to their toxicity. Modafinil treatment should be carefully monitored if taken with any of these drugs. Drugs which may have reduced effectiveness if taken with modafinil include cyclosporine (Sandimmune), theophylline, and hormonal contraceptives such as progestin-only or estrogen and progesterone containing drugs (for example, Micronor, Ortho-Novum 1/50). Alternative hormonal contraceptives or an additional non-drug form of contraception should be considered during treatment with modafinil, and treatment should continue for one month after modafinil therapy ends (since the effects of modafinil on contraceptive hormones may continue for several weeks). The effects of modafinil on hormonal contraceptives occurs if the hormones are taken by mouth, patch, or implant.

Drugs that may show increased effects or toxicity if taken with modafinil include warfarin (Coumadin), diazepam (Valium), propranolol (Inderal), imipramine (Tofranil), desipramine (Norpramin), phenytoin (Dilantin) and mephenytoin (Mesantoin).

Some other drugs that may increase the effectiveness and/or toxicity of modafinil. These drugs include carbamazepine (Tegretol), phenobarbital, and rifampin (Rifadin).

Other drugs, such as ketoconazole (Nizoral) and itraconazole (Sporanox) may reduce the effectiveness of modafinil. Methylphenidate may delay the action of modafinil.

The effect of alcohol on modafinil has not been adequately evaluated. Alcohol probably should be avoided while taking modafinil.

There are no adequate studies that assess effects of modafinil in pregnant women. Intrauterine growth retardation and spontaneous abortion have been reported.

It is not known if modafinil is excreted in human milk.

What preparations of modafinil are available?

Tablets: 100 and 200 mg.

How should I keep modafinil stored?

Modafinil should be stored at room temperature, 15 C - 30 C (59 F - 86 F).