NEURONTIN SIDE EFFECTS
- Generic Name: gabapentin
- Brand Name: Neurontin
SIDE EFFECTS
The following serious adverse reactions are discussed in greater detail in other sections:
- Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity
- Anaphylaxis and Angioedema
- Somnolence/Sedation and Dizziness
- Withdrawal Precipitated Seizure, Status Epilepticus
- Suicidal Behavior and Ideation
- Respiratory Depression
- Neuropsychiatric Adverse Reactions (Pediatric Patients 3 to 12 Years of Age)
- Sudden and Unexplained Death in Patients with Epilepsy
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Postherpetic Neuralgia
The most common adverse reactions associated with the use of NEURONTIN in adults, not seen at an equivalent frequency among placebo-treated patients, were dizziness, somnolence, and peripheral edema.
In the 2 controlled trials in postherpetic neuralgia, 16% of the 336 patients who received NEURONTIN and 9% of the 227 patients who received placebo discontinued treatment because of an adverse reaction. The adverse reactions that most frequently led to withdrawal in NEURONTIN-treated patients were dizziness, somnolence, and nausea.
Table 1 lists adverse reactions that occurred in at least 1% of NEURONTIN-treated patients with postherpetic neuralgia participating in placebocontrolled trials and that were numerically more frequent in the NEURONTIN group than in the placebo group.
TABLE 1: Adverse Reactions in Pooled Placebo-Controlled Trials in Postherpetic Neuralgia
| NEURONTIN N=336 % |
Placebo N=227 % |
|
| Bodv as a Whole | ||
| Asthenia | 6 | 5 |
| Infection | 5 | 4 |
| Accidental injury | 3 | 1 |
| Digestive Svstem | ||
| Diarrhea | 6 | 3 |
| Dry mouth | 5 | 1 |
| Constipation | 4 | 2 |
| Nausea | 4 | 3 |
| Vomiting | 3 | 2 |
| Metabolic and Nutritional Disorders | ||
| Peripheral edema | 8 | 2 |
| Weight gain | 2 | 0 |
| Hyperglycemia | 1 | 0 |
| Nervous Svstem | ||
| Dizziness | 28 | 8 |
| Somnolence | 21 | 5 |
| Ataxia | 3 | 0 |
| Abnormal thinking | 3 | 0 |
| Abnormal gait | 2 | 0 |
| Incoordination | 2 | 0 |
| Respiratory System | ||
| Pharyngitis | 1 | 0 |
| Special Senses | ||
| Amblyopia* | 3 | 1 |
| Conjunctivitis | 1 | 0 |
| Diplopia | 1 | 0 |
| Otitis media | 1 | 0 |
| * Reported as blurred vision | ||
Other reactions in more than 1% of patients but equally or more frequent in the placebo group included pain, tremor, neuralgia, back pain, dyspepsia, dyspnea, and flu syndrome.
There were no clinically important differences between men and women in the types and incidence of adverse reactions. Because there were few patients whose race was reported as other than white, there are insufficient data to support a statement regarding the distribution of adverse reactions by race.
Epilepsy With Partial Onset Seizures (Adjunctive Therapy)
The most common adverse reactions with NEURONTIN in combination with other antiepileptic drugs in patients >12 years of age, not seen at an equivalent frequency among placebo-treated patients, were somnolence, dizziness, ataxia, fatigue, and nystagmus.
The most common adverse reactions with NEURONTIN in combination with other antiepileptic drugs in pediatric patients 3 to 12 years of age, not seen at an equal frequency among placebo-treated patients, were viral infection, fever, nausea and/or vomiting, somnolence, and hostility.
Approximately 7% of the 2074 patients >12 years of age and approximately 7% of the 449 pediatric patients 3 to 12 years of age who received NEURONTIN in premarketing clinical trials discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with withdrawal in patients >12 years of age were somnolence (1.2%), ataxia (0.8%), fatigue (0.6%), nausea and/or vomiting (0.6%), and dizziness (0.6%). The adverse reactions most commonly associated with withdrawal in pediatric patients were emotional lability (1.6%), hostility (1.3%), and hyperkinesia (1.1%).
Table 3 lists adverse reactions that occurred in at least 1% of NEURONTIN-treated patients >12 years of age with epilepsy participating in placebocontrolled trials and were numerically more common in the NEURONTIN group. In these studies, either NEURONTIN or placebo was added to the patient’s current antiepileptic drug therapy.
TABLE 3: Adverse Reactions in Pooled Placebo-Controlled Add-On Trials In Epilepsy Patients >12 years of Age
| NEURONTIN* N=543 % |
Placebo* N=378 % |
|
| Bodv As A Whole | ||
| Fatigue | 11 | 5 |
| Increased Weight | 3 | 2 |
| Back Pain | 2 | 1 |
| Peripheral Edema | 2 | 1 |
| Cardiovascular | ||
| Vasodilatation | 1 | 0 |
| Dieestive Svstem | ||
| Dyspepsia | 2 | 1 |
| Dry Mouth or Throat | 2 | 1 |
| Constipation | 2 | 1 |
| Dental Abnormalities | 2 | 0 |
| Nervous Svstem | ||
| Somnolence | 19 | 9 |
| Dizziness | 17 | 7 |
| Ataxia | 13 | 6 |
| Nystagmus | 8 | 4 |
| Tremor | 7 | 3 |
| Dysarthria | 2 | 1 |
| Amnesia | 2 | 0 |
| Depression | 2 | 1 |
| Abnormal thinking | 2 | 1 |
| Abnormal coordination | 1 | 0 |
| Respiratory Svstem | ||
| Pharyngitis | 3 | 2 |
| Coughing | 2 | 1 |
| Skin and Appendaees | ||
| Abrasion | 1 | 0 |
| Uroaenital Svstem | ||
| Impotence | 2 | 1 |
| Special Senses | ||
| Diplopia | 6 | 2 |
| Amblyopia† | 4 | 1 |
| * Plus background antiepileptic drug therapy † Amblyopia was often described as blurred vision. |
||
Among the adverse reactions occurring at an incidence of at least 10% in NEURONTIN-treated patients, somnolence and ataxia appeared to exhibit a positive dose-response relationship.
The overall incidence of adverse reactions and the types of adverse reactions seen were similar among men and women treated with NEURONTIN. The incidence of adverse reactions increased slightly with increasing age in patients treated with either NEURONTIN or placebo. Because only 3% of patients (28/921) in placebo-controlled studies were identified as nonwhite (black or other), there are insufficient data to support a statement regarding the distribution of adverse reactions by race.
Table 4 lists adverse reactions that occurred in at least 2% of NEURONTIN-treated patients, age 3 to 12 years of age with epilepsy participating in placebo-controlled trials, and which were numerically more common in the NEURONTIN group.
TABLE 4: Adverse Reactions in a Placebo-Controlled Add-On Trial in Pediatric Epilepsy Patients Age 3 to 12 Years
| NEURONTIN* N=119 % |
Placebo* N=128 % |
|
| Bodv As A Whole | ||
| Viral Infection | 11 | 3 |
| Fever | 10 | 3 |
| Increased Weight | 3 | 1 |
| Fatigue | 3 | 2 |
| Dieestive Svstem | ||
| Nausea and/or Vomiting | 8 | 7 |
| Nervous Svstem | ||
| Somnolence | 8 | 5 |
| Hostility | 8 | 2 |
| Emotional Lability | 4 | 2 |
| Dizziness | 3 | 2 |
| Hyperkinesia | 3 | 1 |
| Respiratory Svstem | ||
| Bronchitis | 3 | 1 |
| Respiratory Infection | 3 | 1 |
| * Plus background antiepileptic drug therapy | ||
Other reactions in more than 2% of pediatric patients 3 to 12 years of age but equally or more frequent in the placebo group included: pharyngitis, upper respiratory infection, headache, rhinitis, convulsions, diarrhea, anorexia, coughing, and otitis media.
Postmarketing Experience
The following adverse reactions have been identified during postmarketing use of NEURONTIN. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Hepatobiliary disorders: jaundice
Investigations: elevated creatine kinase, elevated liver function tests
Metabolism and nutrition disorders: hyponatremia
Musculoskeletal and connective tissue disorder: rhabdomyolysis
Nervous system disorders: movement disorder
Psychiatric disorders: agitation
Reproductive system and breast disorders: breast enlargement, changes in libido, ejaculation disorders and anorgasmia
Skin and subcutaneous tissue disorders: angioedema, bullous pemphigoid, erythema multiforme, Stevens-Johnson syndrome.
There are postmarketing reports of life-threatening or fatal respiratory depression in patients taking NEURONTIN with opioids or other CNS depressants, or in the setting of underlying respiratory impairment.
Adverse reactions following the abrupt discontinuation of gabapentin have also been reported. The most frequently reported reactions were anxiety, insomnia, nausea, pain, and sweating.
SRC: NLM .