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Fycompa Side Effects

Generic Name: perampanel

Note: This page contains information about the side effects of perampanel. Some of the dosage forms included on this document may not apply to the brand name Fycompa.

In Summary

Common side effects of Fycompa include: dizziness, drowsiness, falling, hostility, equilibrium disturbance, abnormal gait, aggressive behavior, fatigue, ataxia, and irritability. Other side effects include: anxiety, weight gain, blurred vision, vertigo, and back pain. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to perampanel: oral tablet

In addition to its needed effects, some unwanted effects may be caused by perampanel (the active ingredient contained in Fycompa). In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

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

More common:
  • Aggression or anger
  • anxiety
  • clumsiness or unsteadiness
  • dry mouth
  • hyperventilation
  • irregular heartbeats
  • irritability
  • restlessness
  • shakiness and unsteady walk
  • shortness of breath
  • sleepiness or unusual drowsiness
  • trouble sleeping
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual tiredness or weakness
Less common:
  • Abnormal or decreased touch sensation
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
Incidence not known:
  • Changes in behavior
  • depression
  • thoughts of killing oneself

Minor Side Effects

Some of the side effects that can occur with perampanel 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:
  • Dizziness or lightheadedness
  • feeling of constant movement of self or surroundings
  • headache
  • nausea
  • sensation of spinning
Less common:
  • Back pain
  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • blurred vision
  • body aches or pain
  • bone pain
  • changes in speech patterns
  • chills
  • confusion
  • cough
  • decreased urine output
  • difficulty having a bowel movement (stool)
  • difficulty with moving
  • double vision
  • ear congestion
  • fast or irregular heartbeat
  • fever
  • increased thirst
  • lack or loss of strength
  • loss of voice
  • muscle pain or cramps
  • muscle stiffness
  • nasal congestion
  • nausea or vomiting
  • pain in the arms or legs
  • pain in the joints
  • runny nose
  • slurred speech
  • sneezing
  • sore throat
  • trouble remembering
  • trouble with speaking
  • unusual weight gain or loss
  • unusually deep sleep
Incidence not known:
  • Unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

For Healthcare Professionals

Applies to perampanel: oral suspension, oral tablet


Common (1% to 10%): Nausea (up to 8%), vomiting (up to 4%), constipation (up to 3%)[Ref]


Common (1% to 10%): Weight gain (up to 4%), peripheral edema (up to 2%), hyponatremia (up to 2%)[Ref]


Common (1% to 10%): Back pain (up to 5%), myalgia (up to 3%), pain in extremity (up to 3%), arthralgia (up to 2%), musculoskeletal pain (up to 2%)[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 43%), somnolence (up to 18%), headache (up to 13%), fatigue (up to 12%)

Common (1% to 10%): Ataxia (up to 8%), vertigo (up to 5%), gait disturbance (up to 4%), dysarthria (up to 4%), balance disorder (up to 3%), hypoesthesia (up to 3%), hypersomnia (up to 3%), asthenia (up to 2%), abnormal coordination (up to 2%), memory impairment (up to 2%), paresthesia (up to 2%)[Ref]


Common (1% to 10%): Blurred vision (up to 4%), diplopia (up to 3%)[Ref]


Common (1% to 10%): Falls (up to 10%), head injury (up to 3%), contusion (up to 2%), limb injury (up to 2%), skin laceration (up to 2%)[Ref]


Common (1% to 10%): Irritability (up to 12%), anxiety (up to 4%), aggression (up to 3%), anger (up to 3%), confusional state (up to 2%), euphoric state (up to 2%), mood altered (up to 2%)[Ref]


Common (1% to 10%): Upper respiratory tract infection (up to 4%), cough (up to 4%), oropharyngeal pain (up to 2%)[Ref]


1. "Product Information. Fycompa (perampanel)." Eisai Inc, Teaneck, NJ.

Not all side effects for Fycompa 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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