Neurontin Side Effects

Generic name: gabapentin

Medically reviewed by Drugs.com. Last updated on Nov 23, 2023.

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

Applies to gabapentin: oral capsule, oral solution, oral suspension, oral tablet, oral tablet extended release 24 hr.

Serious side effects of Neurontin

Along with its needed effects, gabapentin (the active ingredient contained in Neurontin) 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
• 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

• Blistering, peeling, or loosening of the skin
• clay-colored stools
• coma
• confusion
• dark urine
• decreased urine output
• diarrhea
• difficult or troubled breathing
• dizziness
• fast or irregular heartbeat
• headache
• increased thirst
• irregular, fast or slow, or shallow breathing
• 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
• pale or blue lips, fingernails, or skin
• red skin lesions, often with a purple center
• red, irritated eyes
• seizures
• stomach pain
• unpleasant breath odor
• vomiting of blood
• yellow eyes or skin

Other side effects of Neurontin

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

Less common or rare

• Accidental injury
• appetite increased
• back pain
• body aches or pain
• burning, dry, or itching eyes
• change in vision
• change in walking and balance
• chest tightness
• clumsiness or unsteadiness
• congestion
• constipation
• cough producing mucus
• decrease in sexual desire or ability
• dryness of the mouth or throat
• earache
• excessive tearing
• eye discharge
• feeling faint, dizzy, or lightheadedness
• feeling of warmth or heat
• flushed, dry skin
• flushing or redness of the skin, especially on the face and neck
• frequent urination
• fruit-like breath odor
• impaired vision
• incoordination
• increased hunger
• increased sensitivity to pain
• increased sensitivity to touch
• increased thirst
• noise in the ears
• pain, redness, rash, swelling, or bleeding where the skin is rubbed off
• redness or swelling in the ear
• redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
• runny nose
• sneezing
• sweating
• tender, swollen glands in the neck
• tingling in the hands and feet
• trouble sleeping
• trouble swallowing
• trouble thinking
• twitching
• unexplained weight loss
• voice changes
• vomiting
• weakness or loss of strength
• weight gain

For Healthcare Professionals

Applies to gabapentin: compounding powder, oral capsule, oral solution, oral tablet, oral tablet extended release.

General

The most common adverse reactions associated with the use of this drug were dizziness, somnolence, and peripheral edema.^[Ref]

Nervous system

Very common (10% or more): Somnolence (21%), dizziness (17%), ataxia (13%)

Common (1% to 10%): Abnormal gait, incoordination, neuralgia, tremor, dysarthria, hyperkinesia, seizures, dysarthria, paresthesia, hypesthesia, coordination abnormal, increased/decreased/absent reflexes, vertigo

Uncommon (less than 1%): Hypokinesia

Rare (less than 0.1%): Movement disorders (e.g., choreoathetosis, dyskinesia, dystonia), loss of consciousness

Frequency not reported: Withdrawal precipitated seizure/status epilepticus

Postmarketing reports: Movement disorder^[Ref]

Respiratory

Reports of life-threatening or fatal respiratory depression have been reported in patients taking this drug with CNS depressants including opioids, or in the setting of underlying respiratory impairment.^[Ref]

Common (1% to 10%): Pharyngitis, dyspnea, cough, bronchitis, respiratory infection, rhinitis

Rare (less than 0.1%): Pulmonary thrombosis, pulmonary embolism

Frequency not reported: Pseudo-croup, hoarseness

Postmarketing reports: Respiratory depression^[Ref]

Hypersensitivity

Very rare (less than 0.01%): Hypersensitivity syndrome, a systemic reaction with a variable presentation that can include fever, rash, hepatitis, lymphadenopathy, eosinophilia, and sometimes other signs and symptoms

Frequency not reported: Anaphylaxis, angioedema^[Ref]

Psychiatric

There are postmarketing reports of withdrawal symptoms shortly after discontinuing this drug. The most frequently reported reactions with abrupt discontinuation have included anxiety, insomnia, nausea, pain, and sweating. Discontinuation at higher than recommended doses have been associated with agitation, disorientation and confusion. These symptoms have resolved after restarting this drug. The dependence potential of gabapentin (the active ingredient contained in Neurontin) has not been evaluated in human studies.^[Ref]

Common (1% to 10%): Abnormal thinking, amnesia, depression, hostility, confusion, emotional lability, anxiety, nervousness, insomnia

Uncommon (0.1% to 1%): Mental impairment

Rare (less than 0.1%): Hallucinations

Frequency not reported: Suicidal behavior and ideation, hypomania

Postmarketing reports: Agitation, withdrawal symptoms^[Ref]

Immunologic

Frequency not reported: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)^[Ref]

Dermatologic

Common (1% to 10%): Abrasion, facial edema, purpura, rash, pruritus, acne

Uncommon (0.1% to 1%): Alopecia, eczema, dry skin, increased sweating, urticaria, hirsutism, seborrhea, cyst, herpes simplex

Rare (less than 0.1%): Stevens-Johnson syndrome, angioedema, erythema multiforme, drug rash (with eosinophilia and systemic symptoms), herpes zoster, skin discolor, skin papules, photosensitive reaction, psoriasis, desquamation, maceration, skin nodules, subcutaneous nodule, melanosis, skin necrosis, local swelling

Frequency not reported: Bullous pemphigoid^[Ref]

Cardiovascular

Common (1% to 10%): Peripheral edema, vasodilation, hypertension

Rare (less than 0.1%): Atrial fibrillation, heart failure, myocardial infarction, cerebrovascular accident, ventricular extrasystoles, bradycardia, premature atrial contraction, pericardial rub, heart block, pericardial effusion, pericarditis

Postmarketing reports: Cardiac arrest, chest pain, palpitation, tachycardia^[Ref]

Endocrine

Rare (less than 0.1%): Hyperthyroid, hypothyroid, goiter, hypoestrogenism, ovarian failure, epididymitis, cushingoid appearance

Postmarketing reports: Breast enlargement, breast hypertrophy, gynecomastia^[Ref]

Gastrointestinal

Common (1% to 10%): Diarrhea, dry mouth or throat, constipation, nausea, vomiting, dyspepsia, dental abnormalities, gingivitis, abdominal pain, flatulence

Uncommon (0.1% to 1%): Glossitis, gum hemorrhage, thirst, stomatitis, increased salivation, gastroenteritis, hemorrhoids, bloody stools, fecal incontinence

Rare (less than 0.1%): Pancreatitis, dysphagia, eructation, pancreatitis, peptic ulcer, colitis, blisters in mouth, tooth discoloration, perlèche, salivary gland enlarged, lip hemorrhage, esophagitis, hiatal hernia, hematemesis, proctitis, irritable bowel syndrome, rectal hemorrhage, esophageal spasm

Frequency not reported: Dehydration^[Ref]

Genitourinary

Common (1% to 10%): Incontinence, impotence

Uncommon (0.1% to 1%): Hematuria, dysuria, urinary frequency, cystitis, urinary retention, vaginal hemorrhage, amenorrhea, dysmenorrhea, menorrhagia

Frequency not reported: Sexual dysfunction (including changes in libido, ejaculation disorders, and anorgasmia)^[Ref]

Hematologic

Common (1% to 10%): Leucopenia, purpura

Uncommon (0.1% to 1%): Anemia, lymphadenopathy

Rare (less than 0.1%): Thrombocytopenia, thrombophlebitis, leukocytosis, lymphocytosis, increased bleeding time

Frequency not reported: Blood creatine phosphokinase increased, coagulation defect^[Ref]

Hepatic

Rare (less than 0.1%): Hepatitis, jaundice, elevated liver function tests (AST, ALT), and bilirubin, hepatomegaly, hepatotoxicity^[Ref]

Metabolic

Common (1% to 10%): Weight gain, hyperglycemia

Postmarketing reports: Hyponatremia^[Ref]

Musculoskeletal

Common (1% to 10%): Back pain, arthralgia, myalgia, twitching

Uncommon (0.1% to 1%): Tendonitis, arthritis, joint stiffness, joint swelling

Frequency not reported: Rhabdomyolysis, myoclonus

Postmarketing reports: Elevated creatine kinase, rhabdomyolysis^[Ref]

Ocular

Common (1% to 10%): Amblyopia, conjunctivitis, diplopia, nystagmus

Uncommon (0.1% to 1%): Cataract, dry eyes, eye pain, visual field defect, photophobia, bilateral or unilateral ptosis, eye hemorrhage, hordeolum, eye twitching

Rare (less than 0.1%): Eye itching, abnormal accommodation, eye focusing problem, watery eyes, retinopathy, glaucoma, iritis, corneal disorders, lacrimal dysfunction, degenerative eye changes, blindness, retinal degeneration, miosis, chorioretinitis, strabismus^[Ref]

Oncologic

Uncommon (0.1% to 1%): Breast cancer

Rare (less than 0.1%): Non-Hodgkin's lymphoma^[Ref]

Other

Very common (10% or more): Fatigue (11%), fever (11%)

Common (1% to 10%): Asthenia, accidental injury, otitis media, tremor, pain

Rare (0.01% to 0.1%): Tinnitus

Very rare (less than 0.01%): Sudden unexplained death in patients with epilepsy

Frequency not reported: Sleepwalking, withdrawal symptoms, hearing loss, earache, tinnitus, inner ear infection, otitis, taste loss, unusual taste, ear fullness, perforated ear drum, sensitivity to noise, eustachian tube dysfunction, otitis externa, odd smell, labyrinthitis^[Ref]

Renal

Rare (less than 0.1%): Acute renal failure^[Ref]

Frequently asked questions

• Should gabapentin be taken with food?
• Lyrica vs Gabapentin: What's the difference?
• Does gabapentin help treat nerve pain?
• Is gabapentin considered a painkiller?
• How long does withdrawal last?
• Is gabapentin safe for dogs?
• Does it cause weight gain?
• Is gabapentin safe for cats?
• How long does it take to work?

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.

Medical Disclaimer