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Modafinil Side Effects

In Summary

Commonly reported side effects of modafinil include: headache and nausea. Other side effects include: anorexia and xerostomia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to modafinil: oral tablet

In addition to its needed effects, some unwanted effects may be caused by modafinil. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking modafinil:

Less common
  • Black, tarry stools
  • blurred vision or other vision changes
  • chest pain
  • chills or fever
  • clumsiness or unsteadiness
  • confusion
  • dizziness or fainting
  • increased thirst and urination
  • mental depression
  • problems with memory
  • rapidly changing moods
  • shortness of breath
  • sore throat
  • trembling or shaking
  • trouble in urinating
  • uncontrolled movements of the face, mouth, or tongue
  • unusual bleeding or bruising
  • unusual tiredness or weakness

If any of the following symptoms of overdose occur while taking modafinil, get emergency help immediately:

Symptoms of overdose
  • Agitation or excitement
  • fast or pounding heartbeat
  • increased blood pressure
  • trouble with sleeping

Severity: Minor

Some of the side effects that can occur with modafinil may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Anxiety
  • headache
  • nausea
  • nervousness
Less common
  • Back pain
  • belching
  • decrease in appetite
  • diarrhea
  • difficulty having a bowel movement
  • dryness of the mouth
  • dryness of the skin
  • feeling of constant movement of self or surroundings
  • flushing or redness of the skin
  • heartburn
  • indigestion
  • muscle stiffness
  • sores, ulcers, or white spots on the lips or in the mouth
  • sour stomach
  • stomach discomfort upset or pain
  • stuffy or runny nose
  • swelling
  • tingling, burning, or prickling sensations in the skin
  • vomiting

For Healthcare Professionals

Applies to modafinil: oral tablet

Nervous system

Very common (10% or more): Headache (up to 34%)
Common (1% to 10%): Dizziness, paresthesia, somnolence, tremor, taste perversion, vertigo, oro-facial dyskinesia, hyperkinesia, hypertonia
Uncommon (0.1% to 1%): Amnesia, migraine, CNS stimulation, incoordination, movement disorder, speech disorder, hypoesthesia
Very rare (less than 0.01%): Tardive dyskinesia, convulsions
Frequency not reported: Cataplexy[Ref]

Gastrointestinal

Very common (10% or more): Nausea (up to 11%)
Common (1% to 10%): Diarrhea, dry mouth, dyspepsia, constipation, flatulence, mouth ulceration, abdominal pain
Uncommon (0.1% to 1%): Reflux, vomiting, dysphagia, glossitis
Frequency not reported: Periodontal abscess[Ref]

General

The development of adverse reactions (skin and hypersensitivity, central nervous system [CNS], psychiatric, and cardiovascular) appear to be related to higher doses; cardiovascular and CNS reactions increase significantly after a total daily dose of more than 400 mg.[Ref]

Cardiovascular

Common (1% to 10%): Palpitations, chest pain, hypertension, tachycardia, vasodilation
Uncommon (0.1% to 1%): Extrasystoles, arrhythmia, bradycardia, hypotension, transient ischemic T-wave changes, abnormal ECG
Rare (less than 0.1%): Increased blood pressure
Very rare (less than 0.01%): Ischemic heart disease
Frequency not reported: Asystole[Ref]

Dermatologic

Common (1% to 10%): Sweating, herpes simplex
Uncommon (0.1% to 1%): Rash, acne, pruritus
Rare (less than 0.1%): Eczema
Frequency not reported: Ecchymosis, serious skin reactions (including Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, Drug Rash with Eosinophilia and Systemic Symptoms, erythema multiforme)[Ref]

Genitourinary

Common (1% to 10%): Urine abnormality, hematuria, pyuria
Uncommon (0.1% to 1%): Urinary frequency
Rare (less than 0.1%): Foul urine odor
Frequency not reported: Urinary tract infection[Ref]

Hematologic

Common (1% to 10%): Eosinophilia
Uncommon (0.1% to 1%): Leukopenia
Postmarketing reports: Agranulocytosis[Ref]

Hepatic

Common (1% to 10%): Increased gamma-glutamyltransferase, increased alkaline phosphatase, abnormal liver function, elevated liver enzymes, eosinophilia[Ref]

Hypersensitivity

Uncommon (0.1% to 1%): Allergic reaction (e.g., hayfever)
Very rare (less than 0.01%): Multi-organ hypersensitivity reactions, urticaria (hives), angioedema, anaphylaxis[Ref]

Metabolic

Common (1% to 10%): Anorexia, thirst, decreased appetite
Uncommon (0.1% to 1%): Hypercholesterolemia, hyperglycemia, diabetes mellitus, increased appetite, increased weight, decreased weight[Ref]

Musculoskeletal

Common (1% to 10%): Back pain, neck rigidity
Uncommon (0.1% to 1%): Neck pain, myalgia, myasthenia, leg cramps, arthralgia, twitch, arthritis
Rare (less than 0.1%): Muscle weakness[Ref]

Ocular

Common (1% to 10%): Abnormal vision, blurred vision, amblyopia, eye pain
Uncommon (0.1% to 1%): Dry eye
Frequency not reported: Conjunctivitis[Ref]

Other

Common (1% to 10%): Chills, edema, asthenia, flu syndrome, thirst
Uncommon (0.1% to 1%): Peripheral edema, menstrual disorder
Rare (less than 0.1%): Tolerance, aggravated condition, malaise, fatigue
Frequency not reported: Infection, pain, accidental injury, fever, viral infection, tooth disorder, hypothermia, ear pain[Ref]

Psychiatric

Common (1% to 10%): Insomnia, anxiety, depression, agitation, nervousness, confusion, emotional lability, abnormal thinking, irritability
Uncommon (0.1% to 1%): Sleep disorder, decreased libido, hostility, depersonalization, personality disorder, abnormal dreams, aggression, suicidal ideation, psychomotor hyperactivity
Rare (less than 0.1%): Hallucinations, mania, psychosis, delusions, suicide attempt[Ref]

Respiratory

Common (1% to 10%): Rhinitis, pharyngitis, lung disorder, asthma, epistaxis
Uncommon (0.1% to 1%): Sinusitis, dyspnea, increased cough
Frequency not reported: Bronchitis[Ref]

References

1. "Product Information. Provigil (modafinil)." Cephalon, Inc, West Chester, PA.

Not all side effects for modafinil may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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