Modafinil Dosage Guide

## Acute Overdose The median lethal dose (LD50) from modafinil for human beings has never been reached, indicating a remarkably wide safety margin. No life-threatening effects have taken place in clinical trials involving the administration of 1000 mg to 1600 mg per day for 7 to 21 consecutive days. Intentional acute overdoses of 4500 mg and 4000 mg in two adult subjects, and an accidental ingestion of 800 mg by a three-year-old child, did not result in any life-threatening effects or death. After overdosing on 5000 mg of modafinil in a suicide attempt, a fifteen-year-old female reported a severe headache, nausea, and tachycardia, but did not appear to have any lethal or long-term effects. ## Overdose Symptoms At supratherapeutic doses, the most commonly reported symptoms include: - Severe headache - Nausea and vomiting - Tachycardia (rapid heartbeat) - Insomnia lasting 24+ hours - Anxiety and restlessness - Elevated blood pressure ## Management Modafinil overdose is managed with supportive care. There is no specific antidote. In cases of significant overdose, cardiovascular monitoring is appropriate. Benzodiazepines may be used to manage anxiety and insomnia resulting from overdose. Due to the long half-life, symptoms may persist for 12-24 hours or longer. ## Combination Risks While modafinil alone has an excellent safety record, combinations with other stimulants should be approached with caution. Community reports include a case of seizure following the combination of modafinil with methylcyclazodone (a potent eugeroic), heavy caffeine consumption, and cannabis. Users who stack multiple wakefulness-promoting agents or combine modafinil with high doses of caffeine should be aware of the potential for additive cardiovascular stress and possible lowering of the seizure threshold. Disruption of sleep architecture from chronic modafinil use combined with other wakefulness agents can lead to severe cumulative sleep deprivation. One community report describes a user who stayed awake for approximately 48 hours using modafinil combined with prescribed medications, followed by a prolonged rebound sleep period of nearly 48 hours, illustrating the risks of sustained wakefulness. Call emergency services if symptoms include chest pain, severe tachycardia, seizures, or loss of consciousness. Good Samaritan laws apply.