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Fycompa Side Effects

Generic Name: perampanel

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

In Summary

Common side effects of Fycompa 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 (the active ingredient contained in Fycompa) 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 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. "Australian Product Information." O 0

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

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

Some side effects of Fycompa may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.