Modafinil is an oral drug that is used for improving wakefulness in patients with excessive sleepiness. The effect of modafinil is similar to caffeine. Both drugs promote wakefulness by stimulating the brain. Thus both drugs are considered stimulants. Other stimulants for example dextroamphetamine Dexedrine and sibutramine Meridia also have the different effect of suppressing appetite. All four of these drugs affect the neurotransmitters in the brain the chemicals that the nerves of the brain use to communicate with each other however they affect the neurotransmitters differently. Modafinil was approved by the FDA in December 1998.

Modafinil usually is taken at a dose of 200 or 400 mg daily although the 400 mg dose has not been shown to be more effective than the 200 mg dose. Modafinil can be taken with or without food.

The most common side effects of modafinil in clinical trials are headache upper respiratory tract infection nausea nervousness anxiety and insomnia. These each occur in more than 5 of patients.

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 e.g. 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.

It is not clear if there are interactions between modafinil and alcohol.

Modafinil is used to promote wakefulness in patients with excessive sleepiness associated with narcolepsy obstructive sleep apnea/hypopnea syndrome as an adjunct for treatment of the underlying obstruction and shiftwork sleep disorder. Narcolepsy is a chronic disease of the brain and spinal cord characterized most commonly by a recurrent uncontrollable desire to sleep. Shiftwork sleep disorder is a condition in which the normal rhythm of sleep is disturbed often as a result of working at night.

Modafinil should be stored at room temperature 15-30°C59-86°F.