modafinil, Provigil (cont.)

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DOSING: 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.

DRUG INTERACTIONS: 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.



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