What Are the Side Effects of Gabapentin (Neurontin)?

Key Takeaways

• Gabapentin (Neurontin) is prescribed for seizures and nerve pain and is used off-label for many other conditions; off-label prescribing accounts for an estimated 95% of its use
• Most side effects are mild, including dizziness, fatigue, and stomach issues, and often improve over time
• Serious side effects include breathing problems, mood changes, and status epilepticus in epileptic patients who stop suddenly
• Misusing gabapentin or combining it with opioids or alcohol significantly increases the risk of overdose
• Older adults, children, and people with kidney disease face elevated risks
• Gabapentin carries a risk of misuse and psychological dependence, particularly among people with a history of substance use disorders

What Is Gabapentin Used For?

Gabapentin, commonly known by the brand name Neurontin, is an anticonvulsant medication approved by the FDA to treat seizures and nerve pain from shingles (post-herpetic neuralgia). It works by reducing abnormal electrical activity in the brain and altering how the nervous system responds to pain signals.

Beyond its approved uses, gabapentin is prescribed off-label for a wide range of conditions, including:

• Diabetic neuropathy and other nerve pain conditions
• Restless leg syndrome
• Alcohol withdrawal support
• Anxiety disorders
• Insomnia
• Hot flashes
• Bipolar disorder and PTSD

Gabapentin enacarbil, sold under the brand name Horizant, is an extended-release formulation approved specifically for restless leg syndrome and postherpetic neuralgia.

Common Side Effects of Gabapentin

Many common side effects are mild and tend to improve as the body adjusts to the medication.[2] You might experience:

• Dizziness
• Drowsiness or fatigue
• Coordination problems (ataxia)
• Stomach discomfort or diarrhea
• Fever
• Nausea

If these symptoms persist or worsen, your doctor may adjust your dosage or the timing of your doses.

Gabapentin Side Effects in the Elderly

Older adults face compounded risks from gabapentin that younger patients typically don't. The drug's half-life is five to seven hours under normal conditions, but kidney function naturally declines with age, which slows gabapentin elimination and causes it to accumulate at higher concentrations in the body.

Specific risks that are elevated in older adults include:

• Dizziness and impaired coordination, raising fall risk significantly
• Excessive sedation and cognitive dulling
• Confusion and memory problems
• Longer and more intense side effects due to slower clearance
• Greater sensitivity to respiratory depression, particularly when combined with opioids or other CNS depressants

Doctors typically start older patients on lower doses and adjust more gradually than they would for younger adults. Regular monitoring of kidney function is standard practice during long-term gabapentin use in this population.

Gabapentin Side Effects in Children

Children can benefit from gabapentin for epilepsy management, but they may respond differently than adults, particularly when it comes to behavior.

Common side effects in children include fatigue, dizziness, and coordination problems, similar to adults. The more distinctive concern in pediatric patients is behavioral change. You might notice:

• More frequent or intense tantrums
• Increased aggression or hostility
• Hyperactivity
• Defiance or oppositional behavior
• Worsening of existing behavioral challenges

These changes can often be managed by adjusting the dosage. In more severe cases, discontinuing the medication may be necessary. Research suggests that once gabapentin is stopped, these behavioral changes typically resolve without lasting effects. Gabapentin is not approved for children under age three.

Serious Side Effects of Gabapentin

Some gabapentin side effects require immediate medical attention.

Neurological Effects

There have been documented cases of chorea, a condition involving sudden involuntary muscle movements, in patients taking gabapentin. In reported cases, symptoms improved after the medication was stopped.

People with myasthenia gravis should use gabapentin with particular caution, as it has been shown to worsen muscle weakness in this condition.[1] A thorough review of medical history with your provider before starting treatment is especially important for this group.

Breathing and Respiratory Risks

Gabapentin has been linked to hypoventilation and respiratory failure in rare cases.[2] The risk increases significantly when gabapentin is combined with opioids, benzodiazepines, or other CNS depressants. People with pre-existing respiratory conditions such as asthma or COPD face elevated risk.

There have also been concerns about mitochondrial toxicity, which can affect how cells produce energy and may contribute to muscle weakness with prolonged use.

Status Epilepticus Risk

Epileptic patients who stop gabapentin suddenly face the risk of status epilepticus, a medical emergency in which seizures continue for more than 30 minutes. This can be fatal if not treated immediately. Gabapentin should never be stopped abruptly in someone with a seizure disorder. Any change in dose or discontinuation must be done gradually and under medical supervision.

Cognitive and Behavioral Side Effects

Gabapentin can affect mental clarity and emotional regulation. These changes range from mild to serious and are more likely at higher doses or in people with kidney disease, which slows the drug's clearance.

Potential cognitive and behavioral effects include:

• Confusion or reduced alertness
• Memory problems
• Intrusive thoughts
• Suicidal thoughts or ideation
• Self-harm behaviors

Older adults are more sensitive to these changes. If you notice shifts in mood, thinking, or behavior while taking gabapentin, contact your doctor promptly rather than waiting to see if they resolve on their own.

Suicidal Thoughts and Self-Harm Risk

The FDA requires anticonvulsant medications, including gabapentin, to carry a warning about increased risk of suicidal thoughts and behaviors. While this is not common, it must be taken seriously.

Between 2006 and 2013, a report found that 5.2% of individuals with gabapentin prescriptions were treated for suicidal behavior or died from it. If you or someone you care about starts taking gabapentin, having additional mental health support in place provides an important layer of monitoring. If suicidal thoughts develop or worsen after starting the medication, seek help immediately or call 988 (the Suicide and Crisis Lifeline).

Sexual Side Effects of Gabapentin

Sexual side effects are not among the most commonly reported gabapentin effects, but they are documented and worth knowing about.

In men, sexual dysfunction is the primary concern, including reduced libido and difficulty with arousal. In women, anorgasmia has been reported across multiple case studies, with evidence suggesting the effect is dose-dependent. In documented cases, orgasmic function returned after the medication was discontinued or the dose was reduced.

Interestingly, gabapentin has also shown potential to improve sexual function in some contexts, particularly in women with anxiety-related sexual dysfunction, where calming the nervous system may reduce inhibitory responses. If sexual side effects are a concern, your doctor can discuss dosage adjustments or alternative approaches.

Visual Side Effects

Some people experience vision-related changes while taking gabapentin. A rare but documented side effect is constriction of the visual field, which can affect peripheral or central vision.[6] Changes to parts of the eye involved in visual processing have also been reported, though research is ongoing.

Report any changes in vision to your doctor right away. In documented cases, visual field changes improved after gabapentin was discontinued.

Gabapentin and Weight Gain

Weight gain is not listed as a primary gabapentin side effect, but changes in appetite have been reported, particularly in studies involving patients with autism spectrum disorder, where increased appetite was a notable finding. Gabapentin's influence on serotonin and dopamine may also shift food perception and cravings in some individuals.

For most patients taking gabapentin at standard doses for nerve pain or seizures, significant weight gain is unlikely. If you notice unexpected changes in appetite or weight, bring them up with your doctor early so they can be tracked.

Gabapentin for Sleep

Gabapentin is sometimes prescribed off-label for insomnia, particularly in people who also have chronic pain, anxiety, or restless leg syndrome. Its sedating effect can help some people fall asleep more easily or stay asleep longer.

Because this is not an FDA-approved use, relying on gabapentin as a long-term sleep aid carries risks. The body can adapt to its sedating effects over time, making sleep without it progressively harder. Some people also begin increasing their dose in search of stronger sedation, which raises the risk of side effects and dependence.

If gabapentin is being used for sleep, it should be part of a broader treatment plan that addresses the underlying causes of insomnia, done under consistent medical supervision.

Gabapentin and Alcohol

Combining gabapentin and alcohol is dangerous. Both depress the central nervous system, and when taken together their effects amplify each other rather than simply adding together.

The combination can cause:

• Extreme drowsiness and sedation
• Impaired coordination and balance
• Slowed reaction time and poor judgment
• Respiratory depression, which can be life-threatening in higher doses or in sensitive individuals

Alcohol also undermines gabapentin's therapeutic goals. In people with seizure disorders, alcohol lowers the seizure threshold, making seizures more likely. For people using gabapentin off-label for anxiety, alcohol's rebound effect worsens the anxiety it temporarily suppresses.

Healthcare providers consistently recommend avoiding alcohol entirely while taking gabapentin.

Gabapentin and Pregnancy

If you are pregnant or planning to become pregnant, discuss gabapentin use with your doctor before starting or continuing treatment. The FDA classifies gabapentin as a Category C drug for pregnancy, meaning animal studies have shown potential risks, but adequate human studies are lacking.

Current evidence has not established clear harm to developing fetuses, but questions remain about potential risks, including low birth weight and preterm delivery. Gabapentin passes into breast milk; one study found infant blood levels at approximately 12% of the mother's levels, with no side effects noted in the six infants studied. Despite this finding, women using gabapentin should always discuss breastfeeding with their provider, given the limited research available.

Can Gabapentin Get You High? 

At higher-than-prescribed doses, some people report experiencing euphoria, relaxation, or a floating sensation from gabapentin. This is why recreational use and searches for "gabapentin high" have increased in recent years.[3]

Gabapentin misuse is most common among people with a history of substance use disorders and is frequently paired with opioids, a combination that dramatically increases overdose risk. A postmortem study of 104 people who had gabapentin in their blood found that 47.1% had the medication as a direct factor in their deaths, and many had other substances in their system as well.

Is Gabapentin Addictive?

Gabapentin is not classified as a controlled substance federally, though several U.S. states have begun scheduling it or requiring prescription drug monitoring program tracking due to rising misuse rates.[5] It does not bind to receptors the way highly addictive substances do, but it can produce psychological dependence, particularly in people who use it for its calming or sedating effects.

Who Is Most at Risk for Misuse?

Misuse is more likely among individuals who:

• Have a history of substance use disorders
• Are trying to enhance the effects of other drugs
• Use gabapentin in higher doses than prescribed

Risks of Combining Gabapentin With Other Substances

Combining gabapentin with opioids is one of the most dangerous patterns of misuse.[4] The combination suppresses breathing more aggressively than either substance alone, and overdose can occur at doses that would be individually tolerable. Alcohol carries similar risks. If you are using gabapentin alongside other substances and finding it difficult to stop, seeking support can significantly reduce your risk of serious complications.

Find Treatment for Gabapentin Misuse

If gabapentin use has become difficult to manage, or you're using it outside of a prescription, you don't have to figure it out alone. Better Addiction Care connects people with personalized treatment options at rehab centers across the country, with no hidden costs and no obligation to commit.

Call or reach out to Better Addiction Care today to speak with a client care specialist about your options.