Modafinil belongs to the psychoanaleptics and is used for the treatment of narcolepsy as well as off-label for depression or fatigue syndrome.


Modafinil was developed in France in the 1980s. The drug belongs to a group of psycho-stimulant drugs. It is approved in Germany for the treatment of excessive drowsiness associated with narcolepsy with or without concomitant cataplexy. You can buy it from

Other applications are off-label and include z. Chronic fatigue syndrome or depression.

Pharmacodynamics (effect)

Modafinil belongs to the psychoanaleptics. It is a centrally active sympathomimetic and acts as a psychostimulant. The exact mechanism of action by modafinil which promotes alertness is currently unknown. The drug appears to act as a dopamine reuptake inhibitor, which would explain the pregnancy-promoting effect. In addition, modafinil inhibits norepinephrine reuptake, but in a weaker form than the effects observed at the dopamine receptor.


The maximum plasma concentration of modafinil is reached 2-4 hours after ingestion, the plasma half-life  is 10 – 12 hours with a single dose of the drug, with continuous ingestion at steady state 15 hours. The active ingredient has a moderate binding (60%) to plasma proteins and is mainly bound to albumin. The metabolism of modafinil occurs in the liver. The excretion of the drug is mainly via
the kidney.
Here is the full video about modafinil:


Modafinil or modalert is administered orally. Film-coated tablets with Modafinil should be consumed whole and chewed with a glass of water. The recommended initial daily dose is 200 mg. The total daily dose can be taken as a single dose or divided into two doses (morning and noon). In case of insufficient response to therapy it is possible to increase the daily dosage to 400 mg.

Limited kidney function

There is insufficient data on the safety and efficacy of the drug in patients with renal impairment.

Limited liver function

The dose of modafinil should be halved in patients with impaired liver function.

Elderly patients

Insufficient information is available on the use of modafinil in the elderly. Assuming that clearance could be reduced and systemic availability increased, it is recommended to start the dosage at 100 mg daily.

Side effects

Modafinil therapy can cause many side effects. The following are possible side effects listed by frequency.

Very often

  • A headache.


  • Decreased appetite
  • nervousness
  • insomnia
  • fear
  • depression
  • thought disorder
  • confusion
  • irritability
  • giddiness
  • somnolence
  • paresthesia
  • Blurred vision
  • Tachycardia, palpitations
  • vasodilation
  • stomach pain
  • nausea
  • Diarrhea or constipation
  • asthenia
  • Chest pain.


  • Pharyngitis, sinusitis
  • Eosinophilia, leukopenia
  • Slight allergic reaction
  • hypercholesterolemia
  • hyperglycemia
  • Diabetes mellitus
  • Increased appetite
  • sleep disorders
  • emotional lability
  • decreased libido
  • personality disorder
  • depersonalization
  • aggression
  • suicidal thoughts
  • dyskinesias
  • amnesia
  • migraine
  • tremor
  • dysgeusia
  • speech disorders
  • Dry eye
  • extrasystoles
  • arrhythmia
  • Hypertensionor hypotension
  • Dyspnea, asthma
  • to cough
  • flatulence
  • Vomit
  • glossitis
  • mouth ulcers
  • sweat
  • skin rash
  • acne
  • pruritus
  • Back pain, neck pain
  • Abnormal urine
  • menstrual disorders
  • Peripheral edema


  • hallucinations
  • manias


Modafinil may interact with the following active ingredients:

  • Anticonvulsants: By anticonvulsants, e.g. as carbamazepineor phenobarbital , the plasma level of modafinil can be reduced. In addition, modafinil could reduce the clearance of phenytoin . Therefore, attention must be paid to patients with phenytoin toxicity.
  • Hormonal contraceptives: Modafinil may affect the efficacy of hormonal contraceptives. Alternative / additional contraceptive measures are therefore recommended for patients on modafinil therapy and for up to two months after discontinuation of modafinil.
  • Antidepressants: Serum levels of tricyclic antidepressants and selective serotonin reuptake inhibitors may be elevated in patients with CYP2D6 deficiency (approximately 10% of the Caucasian population). Patients may require a lower dose of antidepressants.
  • Anticoagulants: Warfarin clearance may be reduced by modafinil. Prothrombin time should therefore be monitored regularly during the first two months of modafinil therapy.

Drugs with CYP metabolism

Drugs that are metabolised primarily by the CYP2C19 metabolism (e.g. diazepam , propranolol , omeprazole ) may show reduced clearance when administered modafinil, which would result in a necessary dose reduction.

In addition, CYP1A2, CYP2B6 and CYP3A4 / 5 activity were observed in vitro. If this were also to occur in vivo, the plasma levels of the active substances metabolised by these enzymes could be reduced. The therapeutic efficacy would be reduced. Clinical interaction studies indicate that CYP3A4 / 5 substrates in particular may be affected. Examples of substrates would be ciclosporin, HIV protease inhibitors, buspirone, triazolam, midazolam, as well as many calcium channel blockers and statins .


Modafinil should not be used if there is a hypersensitivity to the active substance or any of the components of the drug. The drug is also contraindicated in patients with uncontrolled moderate to severe hypertension and in patients with cardiac arrhythmias. Children and adolescents under the age of 18 should not be treated with modafinil.

Pregnancy / Breastfeeding

Modafinil has limited experience of use during pregnancy. It is recommended not to use the drug during pregnancy. As the active substance may reduce the efficacy of hormonal contraceptives it is recommended to use additional contraceptive methods.

Data from animal experiments show that modafinil passes into breast milk. It should therefore not be used during breast-feeding.

Fertility data on modafinil treatment are not available.


Since patients who are prescribed the drug already suffer from excessive drowsiness, they should be advised that their alertness may not fully normalize. In addition, the degree of drowsiness should be monitored regularly and patients should be advised to refrain from driving or operating machinery.

In addition, Modafinil can cause side effects such as blurred vision and dizziness, which also negatively affect the ability to drive or operate machinery.

Further information can be found in the respective technical information.


As an alternative preparation for the treatment of narcolepsy in Germany methylphenidate is still approved. In addition, if a severe cataplexy or cataplexy and late night sleep can still sodium oxybate can be used. For further information on possible alternatives, the respective guidelines should be consulted.

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