Neurontin is an anticonvulsant drug used to treat certain types of epilepsy and pain associated with herpes zoster or shingles. It is manufactured by Pfizer and has been the subject of a number of investigations and fines over accusations of illegal marketing.
Originally manufactured but Warner-Lambert, Neurontin was approved in 1994 as an adjunctive treatment for partial seizures, to be used with other medications. It was later approved for the treatment of pain associated with shingles or postherpetic neuralgia (PHN). In 2000, Warner-Lambert became a part of Pfizer pharmaceuticals, one of the largest pharma companies in the world. At its height, Neurontin sales were said to have exceeded $2.7 billion per year, in part, due to off-label marketing.
|Dosage form(s)||100mg capsule|
250mg/5ml oral solution
|Normal dosage||600 to 1800mg/day divided in two or three doses|
pediatric dosing by weight
Neurontin is approved for:
- Management of postherpetic neuralgia in adults
- Add-on treatment in partial onset seizures in adults and children over 3 years of age
Neurontin has also been used as “off-label” treatment for bipolar disorder, refractory depression, anxiety, restless leg syndrome, diabetic neuropathy, insomnia, fibromyalgia, migraine headaches, drug withdrawal and other psychiatric or neurological conditions. Medications may be used off-label for conditions which have not been approved by the U.S. Food and Drug Administration (FDA), but manufacturers are prohibited from marketing or advertising drugs for off-label purposes.
Neurontin Side Effects
All medications may cause side effects, most of which are mild to moderate and may go away with time. Other Neurontin side effects may be more severe or serious.
Common Neurontin side effects include:
- Nausea and vomiting
- Lack of coordination
- Difficulty with speaking
- Swelling of legs and feet
- Jerky movements
- Double vision
- Unusual eye movements
More severe side effects include:
- Violent or aggressive behavior
- Suicidal thoughts or actions
- Anxiety or irritability
- Aggressive behavior
- Panic attacks
- Allergic reactions
Sudden or worsening symptoms should be reported to a medical professional right away.
Neurontin may also cause symptoms of withdrawal if the medication is suddenly discontinued. In some cases, sudden withdrawal may precipitate seizures and should be reported to a physician. Symptoms of withdrawal usually occur in people who have used the drug for a long period of time and may be worsened if it has been misused. Symptoms of withdrawal have included:
- Rapid heart rate
Neurontin Off-label Marketing Lawsuits and Settlements
In 2003, Neurontin became the subject of one of the largest exposures of illegal marketing practices in pharmaceutical history, when a Dateline NBC story aired regarding Warner-Lambert’s promotion of off-label uses. Warner-Lambert had been acquired by Pfizer in 2000 and even though some of the charges occurred before the acquisition, the company was accused of continuing and expanding the illegal practice of off-label marketing.
Related to the television exposé and whistleblower action, in May of 2004, Pfizer pled guilty to criminal charges and paid $430 million in fines for illegal marketing of Neurontin for bipolar disorder, ADHD, migraines and other pain conditions. Emails which emerged long after the trial was settled, indicated that company executives were well aware that the drug was not effective for many of its purported uses including one email in which an executive medical director stated that gabapentin was essentially a modern-day “snake oil”.
In 2014, the company agreed to pay $325 million to settle a decades old lawsuit for similar charges regarding unapproved use marketing, filed by third-party payers. The same year, Pfizer paid another $190 million to settle an antitrust lawsuit regarding the company’s efforts to keep a generic version of gabapentin off of the market. Pfizer had also paid $2.3 billion to settle similar charges for other drugs, including $1.3 billion in criminal penalties.
Neurontin users have claimed that they have been unnecessarily subjected to potential harm for a drug that was marketed for uses not approved by the FDA. No further lawsuit settlements or dispositions have been publicly announced but as Neurontin or gabapentin is still a popular medication which may cause injury or harm, Neurontin attorneys and lawyers will remain watchful.