Neurontin Adverse Reactions

Epilepsy: Gabapentin has been evaluated for safety in more than 2000 subjects and patients in adjunctive therapy studies and was well tolerated. Of these, 543 patients participated in controlled clinical trials. Since gabapentin was most often administered in combination with other antiepileptic agents, it was not possible to determine which agent(s), if any, was associated with adverse events.
Incidence in controlled adjunctive therapy clinical trials: Table 4 lists the treatment-emergent signs and symptoms that occurred in at least 1% of patients with partial seizures participating in placebo-controlled adjunctive therapy studies. In these studies, either gabapentin or placebo was added to the patient's current antiepileptic drug therapy. Adverse events were usually reported as mild to moderate. (See Table 4.)

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Other adverse events observed during all clinical trials: Adjunctive therapy: Those events that occurred in at least 1% of the study participants with epilepsy who received gabapentin as adjunctive therapy in any clinical study and that are not described in the previous section as frequently occurring treatment-emergent signs and symptoms during placebo-controlled studies are summarized as follows.
Body as a Whole: Asthenia, malaise, facial edema.
Cardiovascular System: Hypertension.
Digestive System: Flatulence, anorexia, gingivitis.
Hematologic and Lymphatic Systems: Purpura, most often described as bruises resulting from physical trauma.
Musculoskeletal System: Arthralgia.
Nervous System: Vertigo; hyperkinesia; increased, decreased or absent reflexes; paresthesia; anxiety; hostility.
Respiratory System: Pneumonia.
Urogenital System: Urinary tract infection.
Special Senses: Abnormal vision, most often described as a visual disturbance.
Geriatric use: Fifty-nine individuals aged 65 years or older received gabapentin in pre-marketing clinical trials. Side effects reported among these patients did not differ in kind from those reported in younger individuals. For patients with compromised renal function, the dose should be adjusted (see Dose adjustment in impaired renal function for patients with neuropathic pain or epilepsy and Dose adjustment in patients undergoing hemodialysis under Dosage & Administration).
Pediatric use: The most commonly observed adverse events reported with the use of gabapentin in combination with other antiepileptic drugs in children aged 3 to 12 years, not seen in equal frequency among placebo-treated patients, were viral infection, fever, nausea and/or vomiting, and somnolence. (See Table 5.)

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Other events in more than 2% of children that occurred equally or more frequent in the placebo group included pharyngitis, upper respiratory infection, headache, rhinitis, convulsions, diarrhea, anorexia, coughing, and otitis media.
Withdrawal from treatment due to adverse events: Adjunctive therapy: Approximately 7% of the more than 2000 healthy volunteers and patients with epilepsy, spasticity, or migraine who received gabapentin in clinical studies withdrew due to adverse events.
In all clinical studies, the most frequently occurring events that contributed to discontinuation of gabapentin included somnolence, ataxia, dizziness, fatigue, and nausea and/or vomiting. Almost all participants had multiple complaints, none of which could be characterized as primary.
Pediatric: Approximately 8% of the 292 children aged 3 to 12 years who received gabapentin in clinical trials discontinued treatment because of an adverse event. The adverse events most commonly associated with withdrawal in children were somnolence, hyperkinesia, and hostility.
Neuropathic pain: (See Table 6.)

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Post-marketing experience: Sudden, unexplained deaths have been reported where a causal relationship to treatment with gabapentin has not been established.
Additional post-marketing adverse events reported include blood creatine phosphokinase increased, rhabdomyolysis, acute kidney failure, agitation, allergic reaction including urticaria, alopecia, anaphylaxis, angioedema, hyperglycemia and hypoglycemia (most often observed in patients with diabetes), breast hypertrophy, chest pain, drug rash with eosinophilia and systemic symptoms, elevated liver function tests (LFTs), erythema multiforme, fall, generalized edema, gynecomastia, hallucinations, hepatitis, hypersensitivity including systemic reactions, hyponatremia, jaundice, loss of consciousness, movement disorders, such as choreoathetosis, dyskinesia, and dystonia, myoclonus, palpitation, pancreatitis, sexual dysfunction (including changes in libido, ejaculation disorders and anorgasmia), Stevens-Johnson syndrome, thrombocytopenia, tinnitus and urinary incontinence.
Adverse events following the abrupt discontinuation of gabapentin have also been reported. The most frequently reported events were anxiety, insomnia, nausea, pain, and sweating.
Rare cases of gabapentin with respiratory depression have been reported (see Precautions).