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

Summary

Common side effects of Neurontin include: ataxia, dizziness, drowsiness, fatigue, fever, nystagmus disorder, and viral infection. Other side effects include: blurred vision, diplopia, peripheral edema, tremor, amblyopia, and xerostomia. Continue reading for a comprehensive list of adverse effects.

Applies to gabapentin: oral gabapentin conventional capsules and tablets, oral gabapentin conventional oral solution, oral gabapentin enacarbil extended-release tablets, oral gabapentin gastroretentive tablets.

Side effects include:

Children 3–12 years of age receiving conventional (immediate-release) gabapentin (the active ingredient contained in Neurontin) as adjunctive therapy for partial seizures: viral infection, fever, nausea and/or vomiting, somnolence, hostility.

Adults and children >12 years of age receiving conventional (immediate-release) gabapentin as adjunctive therapy for partial seizures: somnolence, dizziness, ataxia, fatigue, nystagmus.

Adults receiving conventional (immediate-release) gabapentin for management of PHN: dizziness, somnolence, peripheral edema.

Adults receiving gabapentin gastroretentive tablets for PHN: dizziness.

Adults receiving gabapentin enacarbil for PHN: dizziness, somnolence, headache.

Adults receiving gabapentin enacarbil for restless legs syndrome: somnolence/sedation, dizziness.

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]