Along with its needed effects, gabapentin 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 gabapentin:
More common
- Clumsiness or unsteadiness
- continuous, uncontrolled, back-and-forth, or rolling eye movements
More common in children
- Aggressive behavior or other behavior problems
- anxiety
- concentration problems and change in school performance
- crying
- depression
- false sense of well-being
- hyperactivity or increase in body movements
- rapidly changing moods
- reacting too quickly, too emotional, or overreacting
- restlessness
- suspiciousness or distrust
Less common
- Black, tarry stools
- chest pain
- chills
- cough
- depression, irritability, or other mood or mental changes
- fever
- loss of memory
- pain or swelling in the arms or legs
- painful or difficult urination
- shortness of breath
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swollen glands
- unusual bleeding or bruising
- unusual tiredness or weakness
Incidence not known
- Abdominal or stomach pain
- blistering, peeling, or loosening of the skin
- clay-colored stools
- coma
- confusion
- convulsions
- dark urine
- decreased urine output
- diarrhea
- dizziness
- fast or irregular heartbeat
- headache
- increased thirst
- itching or skin rash
- joint pain
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- loss of appetite
- muscle ache or pain
- nausea
- red skin lesions, often with a purple center
- red, irritated eyes
- unpleasant breath odor
- vomiting of blood
- yellow eyes or skin
Some side effects of gabapentin 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
- Blurred vision
- cold or flu-like symptoms
- delusions
- dementia
- hoarseness
- lack or loss of strength
- lower back or side pain
- swelling of the hands, feet, or lower legs
- trembling or shaking
Gabapentin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- drowsiness
- tiredness or weakness
- dizziness
- headache
- uncontrollable shaking of a part of your body
- double or blurred vision
- unsteadiness
- anxiety
- memory problems
- strange or unusual thoughts
- unwanted eye movements
- nausea
- vomiting
- heartburn
- diarrhea
- dry mouth
- constipation
- increased appetite
- weight gain
- swelling of the hands, feet, ankles, or lower legs
- back or joint pain
- fever
- runny nose, sneezing, cough, sore throat, or flu-like symptoms
- ear pain
- red, itchy eyes (sometimes with swelling or discharge)
Some side effects may be serious. If you experience any of the following symptoms, call your doctor immediately:
- rash
- itching
- swelling of the face, throat, tongue, lips, or eyes
- hoarseness
- difficulty swallowing or breathing
- seizures
- difficulty breathing; bluish-tinged skin, lips, or fingernails; confusion; or extreme sleepiness
Gabapentin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).