Modafinil dosing

In a steady-state study, 23 healthy subjeets were given modafinil 200 mg daily for 7 days, followed by 400 mg daily for 3 weeks. During the last week, 10 of the subjeets were also given dexamfetamine 20 mg daily, 7 hours after their modafinil dose. Dexamfetamine eaused no significant change in the pharmacokinetics of modafinil and fhe combination was well tolerated. In addition, the pharmacokinetics of dexamfetamine did not appear to be affected by modafinil, when compared with values reported in the literature. Similar results were found in a single dose studyNo additional precautions appear to be necessary on concurrent use. 

Substance-Induced Anxiety Disorder. Numerous medicines and drugs of abuse can produce panic attacks. Panic attacks can be triggered by central nervous system stimulants such as cocaine, methamphetamine, caffeine, over-the-counter herbal stimulants such as ephedra, or any of the medications commonly used to treat narcolepsy and ADHD, including psychostimulants and modafinil. Thyroid supplementation with thyroxine (Synthroid) or triiodothyronine (Cytomel) can rarely produce panic attacks. Abrupt withdrawal from central nervous system depressants such as alcohol, barbiturates, and benzodiazepines can cause panic attacks as well. This can be especially problematic with short-acting benzodiazepines such as alprazolam (Xanax), which is an effective treatment for panic disorder but which has been associated with between dose withdrawal symptoms. 

Modafinil (Provigil). The newest stimulant, modafinil, is not, pharmacologically, a true stimulant. Nevertheless, it is an effective treatment for narcolepsy at doses from 200 to 400mg/day. Several studies indicate that modahnil has little potential for abuse and is easier to tolerate than other stimulants. Modafinil has been studied in the treatment of ADHD. Though not approved for marketing by the FDA at the time of this writing, it may gain the indication in the near future. 

Modafinil is a Schedule IV medication and does not require a triplicate prescription. Its mechanism of action is unclear but is thought to differ from those of conventional stimulants. Modafinil is metabolized by the liver and excreted by the kidneys. Its half-life is approximately 15 hours. It is available in 100- and 200-mg tablets. The typical daily dose is 200 00 mg every morning this dose should be reduced in elderly or hepatically impaired patients. 

Stimulants, if taken in the evening, delay sleep onset, impair the continuity of sleep at low doses and curtail its duration at higher doses (Fig. 3.7). Amphetamine-like stimulants and caffeine have different effects on REM sleep, which is unchanged after caffeine but dose-dependently reduced after amphetamine. Modafinil at single doses of 100 and 200 mg has only weak effects on the sleep polygram, with a pattern similar to that of amphetamine. 

The recommended dose of modafinil is 200 mg/day for the treatment of excessive daytime sleepiness associated with narcolepsy however, doses of 400 mg/day are FDA-approved. While there is evidence that the higher dose is well tolerated, it has not been established that it confers additional therapeutic benefit (196). In sleep-deprived subjects, doses of 600 mg/day have been administered, but the preponderance of evidence suggests that 300M00 mg/day is probably sufficient and less likely to produce unwanted side effects. 

Modafinil is rapidly absorbed and produces peak plasma levels in 2-4 hr (196,211). The overall half-life after multiple doses is approximately 15 hr. 

The most common adverse reactions to this medication are headache, nausea, nervousness, anxiety, and insomnia (211). Generally, these reactions are mild or moderate. The frequencies with which the most common treatment-emergent whole-body, digestive, respiratory, and nervous-system adverse experiences have occurred with daily 200- and 400-mg doses in patient populations were headache 50%, nausea 13%, rhinitis 11%, and nervousness 8%. Unlike amphetamine, modafinil is not associated with significant cardiovascular stimulation. 

Pigeau et al. (226) assessed the usefulness of modafinil for preventing fatigue-related declines in alertness and performance and for recovering from decrements that had already occurred. Forty-one soldiers were subjected to 64 hr of continuous wakefulness during which 300-mg doses of modafinil, 20 mg doses of dextroamphetamine, or placebo were administered at 17.5, 47.5, and 57.5 hr. Compared to placebo, both modafinil and amphetamine suppressed the amplitude... 

Wong YN, Simcoe D, Hartman LN, Laughton WB, King SP, McCormick GC, Grebow PE. A double-blind, placebo-controlled, ascending-dose evaluation of the pharmacokinetics and tolerability of modafinil tablets in healthy male volunteers. J Clin Pharmacol 1999 39 30-40. 

Modafinil another wakefulness promoting agent with an unknown mechanism of action used for narcolepsy in adults and being studied for use in children at present dose range is 1 Of MOO mg/day divided bid. Side effects include headaches, anxiety, nausea and nervousness. 

The pharmacokinetics of modafinil are not affected, to a clinically significant extent, by volunteer age or food intake, but both the maximum plasma concentration and the elimination half-life of the drug are increased in patients with hepatic or renal impairment. It was found that peak plasma concentrations of modafinil were reached 2.3 h after a single 200 mg oral dose in healthy volunteers. Over the dose range 200 to 600 mg, the pharmacokinetics of modafinil were linear and dose dependent. Orally administered modafinil is extensively biotransformed in the liver to the inactive metabolites modafinil acid 6 (major metabolite) and modafinil sulphone 7 (minor metabolite), before being eliminated primarily in the... 

CLOPIDOGREL CNS STIMULANTS-MODAFINIL May cause moderate t in plasma concentrations of these substrates Modafinil is a reversible inhibitor of CYP2C19 when used in therapeutic doses Be aware... 

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