Modafinil has been commercialized as a waking drug in 2003 [3]. The normal half-life of modafinil in humans is between 12 to 15 hours [4]. Modafinil consists of R-enantiomer and S-enantiomer as a racemic compound, and the waking effect of R-enantiomer has a longer duration.
Modafinil is well-absorbed with peak plasma concentration reached approximately two to four hours after administration.
The half-life of Modafinil ranges between ten and 12 hours for most patients but can last up to 15 hours for some. Modafinil is metabolized in the liver. Its inactive metabolites are excreted in the urine.
In humans, modafinil is efficient and well tolerated, with no evidence of tolerance developing during 40 weeks of treatment.
Morning-dosed modafinil promotes nocturnal sleep, normalizes sleep architecture, and decreases daytime sleepiness in abstinent cocaine users. These effects may be relevant in the treatment of cocaine dependence.
For patients who require more than 200 mg/day, the dose should be increased, to a maximum of 400 mg/day, in increments of 100 mg as needed and tolerated. The recommended daily dose is 200 mg. modafinil should be taken as a single dose approximately 1 hour prior to the start of the work shift.
Those who use meth can stay awake for several days without feeling like their body needs rest, which can lead to insomnia. Lack of REM sleep: Both serotonin and dopamine cannot be properly reabsorbed by the brain when someone uses meth.
Although the maximum recommended daily dose of modafinil is 400 mg, higher doses have been used. There are some patients in whom adequate control of sleepiness may require a slightly higher dose than 400 mg (400 mg in the am and 200 mg in the early afternoon).
If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses. If you miss a dose of modafinil and you remember it before 12:00 noon the same day, take the missed dose as soon as possible.
Research studies have indicated that modafinil: May be significantly more effective in treating the symptoms of ADHD than placebo. May have comparable efficacy for treating ADHD to methylphenidate (e.g., Ritalin, Concerta) and fewer side effects.
Some patients may benefit from 400-mg doses of modafinil taken once daily compared with 200-mg doses. A split-dose 400-mg regimen may be superior to once-daily dosing for sustaining wakefulness throughout the entire waking day.
In a review of 24 studies that investigated the use of modafinil in healthy, non-sleep-deprived individuals, researchers concluded that modafinil is more likely to help improve attention and learning for more complex thought processes rather than basic tasks.
The safety data from this study suggest that the maximum tolerable single daily oral modafinil dose, without titration, may be 600 mg.
At clinically relevant doses, modafinil significantly increases dopamine in the human brain by blocking dopamine transporters.
Final results of this study showed that modafinil (100 µM/side) prevented the testosterone (100 µg/side) – induced spatial learning deficits in MWM and also increased the quantity of BrdU-positive cells in dentate gyrus in combination evaluations in comparison with testosterone – treated animals.
Modafinil may cause some people to feel dizzy, drowsy, have trouble thinking or controlling movements, or trouble seeing clearly. Make sure you know how you react to this medicine before you drive, use machines, or do other jobs that require you to be alert, well-coordinated, or able to think or see well.
Notes for Consumers: Limit excessive caffeine intake (examples: coffee, teas, colas, chocolate and some herbal supplements) while taking Modafinil. Also avoid medicines containing additional Caffeine whenever possible.
Taking opioids like oxycodone, fentanyl and hydrocodone alongside Modafinil can result in complications. Patients mixing Modafinil with these drugs may experience a drop in Modafinil plasma concentrations and lead to decreased effectiveness.
Administration of Modafinil in a dosage of 200 mg is more effective than 100 mg in maintaining mental alertness and improving subjective sleepiness and fatigue during short duration total sleep deprivation.
The effects of Modafinil on heart are a major concern for patients. Recent studies have found an association between Modafinil and heart disease, especially increase blood pressure, heart failure, and arrhythmia but the exact pathway or mediators is still unclear.
People who take Modafinil without a prescription are most likely to develop a tolerance to it, and are also most likely to increase their dose, which can lead to an overdose. However, a long-term prescription can also lead to Modafinil tolerance if the dose is not managed properly.
Modafinil increased general mood and Negative Affect scales relative to placebo and had a significant effect on Positive Affect scales. These results suggest that modafinil may have general mood-elevating effects accompanied by increased negative affect (anxiety).
“It works for 48 hours or so, but eventually you need to sleep.” Perhaps the most remarkable thing about modafinil is that users don't seem to have to pay back any “sleep debt”. Normally, if you stayed awake for 48 hours straight you would have to sleep for about 16 hours to catch up.
Some are also used to help you sleep. Diphenhydramine (Benadryl, ZzzQuil) and doxylamine (Unisom SleepTabs) are both very sedating and are available over the counter (OTC). Hydroxyzine (Vistaril) is an antihistamine that requires a prescription and also causes drowsiness.