Approval for ADHD in children was rejected in 2006 due primarily to two cases of skin rash, one severe, suspected to have been erythema multiforme or Stevens–Johnson syndrome, among 933 subjects receiving the drug.[10][11][12][13] Cephalon's own label for Provigil now discourages its use by children for any purpose.[14] In some countries, it is also approved for other hypersomnias, like idiopathic hypersomnia. The usual prescribed dosage for these disorders is 200 mg once a day (less commonly, 100 to 400 mg/day in one or two doses). Modafinil has also been linked in many articles to increasing concentration.
For conditions other than shift work sleep disorder, modafinil is normally taken in one dose in the morning or in two doses in the morning and at midday. It is generally not recommended to take modafinil after noon: modafinil is a relatively long-acting drug with a half-life of 15 hours, and taking it during the later part of the day carries a risk of sleep disturbances.[15][unreliable medical source?]
Because of the risk for development of skin or hypersensitivity reactions and neuropsychiatric disorders, the European Medicines Agency has recommended that new patient prescriptions should only be to treat sleepiness associated with narcolepsy.[16] Because any serious side effects will usually appear within the first twelve weeks, the guidance does