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Perampanel Side Effects

In Summary

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

For the Consumer

Applies to perampanel: oral suspension, oral tablet

Along with its needed effects, perampanel may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking perampanel:

More Common

  • Aggression or anger
  • anxiety
  • clumsiness or unsteadiness
  • dry mouth
  • hyperventilation
  • irregular heartbeats
  • irritability
  • restlessness
  • shakiness
  • sleepiness or unusual drowsiness
  • trouble sleeping
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unsteady walk
  • 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

Some side effects of perampanel may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More Common

  • Dizziness or lightheadedness
  • feeling of constant movement of self or surroundings
  • headache
  • nausea
  • sensation of spinning
  • stomach pain

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
  • 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


When comparing the 8 mg and 12 mg once a day doses, the 12 mg dose resulted in somewhat greater reductions in seizure rates but with a substantial increase in adverse reactions.[Ref]

Nervous system

Very common (10% or more): Dizziness/vertigo (47%), somnolence (18%), gait disturbance (13%), headache (13%), irritability (12%)

Common (1% to 10%): Ataxia, dysarthria, gait disturbance, balance disorder, hypoesthesia, abnormal coordination, memory impairment, paresthesia[Ref]


Very common (10% or more): Hostility- and aggression-related reactions (20%), irritability (11%)

Common (1% to 10%): Anxiety, anger, hypersomnia, euphoric mood, disorientation/confusional state, altered mood

Uncommon (0.1% to 1%): Homicidal ideation and/or threat, suicidal ideation, suicide attempt

Frequency not reported: Belligerence, affect lability, agitation, physical assault, paranoia, changed mental status, delusions

Postmarketing reports: Acute psychosis, hallucinations, delirium[Ref]


Very common (10% or more): Fatigue/asthenia/lethargy (15%), falls (10%), limb injury

Common (1% to 10%): Head injury, peripheral edema[Ref]


Common (1% to 10%): Contusion, skin laceration, rash

Postmarketing reports: Drug reaction with eosinophilia and systemic symptoms (DRESS)[Ref]


Common (1% to 10%): Nausea, vomiting, constipation, abdominal pain[Ref]


Common (1% to 10%): Weight gain, hyponatremia, decreased appetite, increased appetite

Frequency not reported: Increased triglycerides[Ref]


Common (1% to 10%): Back pain, myalgia, pain in extremity, arthralgia, musculoskeletal pain, ligament sprain

Frequency not reported: Bone fractures[Ref]


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


Common (1% to 10%): Cough, upper respiratory tract infection, oropharyngeal pain[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. Cerner Multum, Inc. "Australian Product Information." O 0

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

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.