Gabapentin is a widely prescribed medication in the UK for epilepsy and neuropathic pain, including diabetic neuropathy and post-herpetic neuralgia. As a Class C controlled drug, it requires careful prescribing and monitoring. Patients taking gabapentin may wonder whether the medication can affect liver health, particularly regarding fatty liver disease. Understanding the relationship between gabapentin and liver function is important for informed decision-making. This article examines the evidence on whether gabapentin can cause fatty liver, explores the drug's metabolism, and provides guidance on recognising potential liver problems and when to seek medical advice.

Understanding Gabapentin and How It Works

Gabapentin is a prescription medicine licensed in the UK for treating epilepsy and neuropathic pain. Originally developed as an anticonvulsant, it is prescribed for chronic pain conditions such as diabetic neuropathy and post-herpetic neuralgia (shingles pain). Since 1 April 2019, gabapentin has been classified as a Class C controlled drug under Schedule 3 by the Home Office due to its potential for misuse and dependence.

The drug works by binding to the alpha-2-delta subunit of voltage-gated calcium channels in the nervous system, reducing the release of excitatory neurotransmitters. This mechanism helps to calm overactive nerve signals that cause seizures or transmit pain sensations. Unlike many other medications, gabapentin is not metabolised by the liver—it is eliminated almost entirely unchanged through the kidneys. Because it is renally excreted, dose adjustment is required in patients with reduced kidney function (based on estimated glomerular filtration rate, eGFR), but no dose adjustment is needed in liver impairment.

Licensed uses for gabapentin in the UK include:

• Partial seizures (with or without secondary generalisation)

• Peripheral neuropathic pain in adults

• Post-herpetic neuralgia

Gabapentin is sometimes used off-label for other conditions such as anxiety disorders or restless leg syndrome, but evidence for these uses is limited and such prescribing should be specialist-led. NICE advises against initiating gabapentinoids for chronic primary pain, including fibromyalgia.

Gabapentin is typically started at a low dose and gradually increased to minimise side effects such as dizziness, drowsiness, and coordination problems. The medication comes in capsules, tablets, and oral solution forms, with dosing schedules tailored to individual patient needs and kidney function. The Medicines and Healthcare products Regulatory Agency (MHRA) has issued safety warnings about the risk of severe respiratory depression, particularly when gabapentin is taken with opioid medicines, and in older adults or those with respiratory or neurological disease. There is also a recognised risk of dependence and misuse. Understanding how gabapentin works in the body is essential when considering its potential effects on various organ systems, including the liver.

Can Gabapentin Cause Fatty Liver Disease?

There is no established clinical evidence linking gabapentin directly to the development of fatty liver disease (hepatic steatosis). The Summary of Product Characteristics (SmPC) and regulatory data from the MHRA and European Medicines Agency (EMA) do not list fatty liver as a recognised adverse effect of gabapentin therapy. This absence of association is consistent with gabapentin's pharmacokinetic profile—since the drug is not metabolised by the liver and is excreted unchanged by the kidneys, it does not undergo hepatic processing in the way that many other medications do.

Fatty liver disease occurs when excess fat accumulates in liver cells, typically due to factors such as obesity, type 2 diabetes, excessive alcohol consumption, metabolic syndrome, or certain medications. Non-alcoholic fatty liver disease (NAFLD) affects up to one in three adults in the UK and is closely linked to lifestyle and metabolic factors rather than specific medications. When medications do cause hepatic steatosis, they typically do so through mechanisms involving altered lipid metabolism, mitochondrial dysfunction, or direct hepatotoxicity—none of which are associated with gabapentin's mechanism of action.

Rare cases of idiosyncratic liver injury have been reported in the medical literature with gabapentin, but these are not characterised as fatty liver disease. The SmPC does not require routine liver function monitoring for patients taking gabapentin. However, it is important to note that patients prescribed gabapentin often have underlying conditions that independently increase their risk of fatty liver disease. For instance, individuals with diabetes (who may receive gabapentin for diabetic neuropathy) or those with limited mobility due to chronic pain conditions may be at higher risk of developing NAFLD due to their primary condition rather than the medication itself. If you have concerns about liver health whilst taking gabapentin, these should be discussed with your GP or specialist, who can assess your individual risk factors and arrange appropriate investigations if needed.

Recognising Liver Problems While Taking Gabapentin

Whilst gabapentin is not known to cause fatty liver disease, it is prudent to be aware of general signs and symptoms that might indicate liver problems, particularly if you have pre-existing liver conditions or other risk factors. Early recognition of potential liver issues allows for timely medical assessment and intervention.

Signs and symptoms that may indicate liver problems include:

• Yellowing of the skin or whites of the eyes (jaundice)

• Persistent fatigue or unusual tiredness

• Dark-coloured urine or pale stools

• Abdominal pain or swelling, particularly in the upper right side

• Unexplained nausea, vomiting, or loss of appetite

• Easy bruising or bleeding

• Itchy skin without an obvious rash

It is important to recognise that these symptoms are non-specific and can occur with many conditions unrelated to medication use. Gabapentin itself commonly causes side effects such as dizziness, drowsiness, peripheral oedema (swelling of the ankles and feet), and gastrointestinal disturbances, but these are distinct from liver-related symptoms.

If you develop any concerning symptoms whilst taking gabapentin, particularly those suggestive of liver dysfunction, you should contact your GP promptly. Your doctor may arrange blood tests to assess liver function (liver function tests or LFTs), which measure enzymes and proteins that indicate how well your liver is working. Routine liver function monitoring is not required in the SmPC for gabapentin; however, clinicians may arrange testing if there are specific clinical indications, pre-existing liver disease, or other risk factors. If you have risk factors for liver disease—such as obesity, diabetes, or a history of alcohol excess—your healthcare team may recommend periodic monitoring as part of your overall care.

Very rarely, gabapentin may be associated with severe hypersensitivity reactions (such as drug reaction with eosinophilia and systemic symptoms, or DRESS) which can involve the liver. Seek urgent medical help if you develop a severe rash with fever, swollen glands, or symptoms affecting multiple organs.

If you experience any side effects whilst taking gabapentin, whether or not they are listed in the patient information leaflet, you should report them via the MHRA Yellow Card Scheme (available at yellowcard.mhra.gov.uk or via the Yellow Card app). Reporting helps improve the safety information available about medicines.

Risk Factors for Liver Issues with Gabapentin

Whilst gabapentin itself does not cause fatty liver disease, certain patient populations may be at increased risk of developing liver problems whilst taking the medication, primarily due to concurrent factors rather than the drug itself. Understanding these risk factors helps patients and healthcare professionals make informed decisions about treatment and monitoring.

Key risk factors that may increase vulnerability to liver problems include:

Pre-existing liver disease: Patients with established liver conditions such as cirrhosis, hepatitis, or existing fatty liver disease require careful monitoring when starting any new medication. Gabapentin does not require dose adjustment in liver impairment (unlike in kidney disease, where dose reduction based on eGFR is essential), but the overall health status of the liver should be considered.

Polypharmacy and drug interactions: Taking multiple medications simultaneously increases the risk of additive side effects. Gabapentin has few pharmacokinetic drug interactions, but it can cause additive central nervous system (CNS) depression when taken with opioids, benzodiazepines, alcohol, or other sedatives. The MHRA has warned that gabapentin combined with opioids increases the risk of severe respiratory depression, particularly in older adults and those with respiratory or neurological disease. Your pharmacist or GP can review your complete medication list to identify potential interactions and ensure safe prescribing.

Metabolic conditions: Diabetes, obesity, and metabolic syndrome are independent risk factors for non-alcoholic fatty liver disease. Many patients prescribed gabapentin for diabetic neuropathy already have these risk factors, which should be managed through lifestyle modifications and appropriate medical treatment.

Alcohol consumption: Excessive alcohol intake is a major cause of liver disease. Alcohol may also enhance the sedative effects of gabapentin and increase the risk of CNS depression. The UK Chief Medical Officers advise drinking no more than 14 units of alcohol per week, spread over at least three days.

Age and frailty: Older adults may be more susceptible to adverse effects from medications, including dizziness, drowsiness, and falls, and may have reduced physiological reserve. NICE recommends regular medication reviews for older patients to ensure continued appropriateness of treatment and to minimise polypharmacy risks.

When to Seek Medical Advice About Gabapentin and Liver Health

Knowing when to contact your healthcare provider is essential for maintaining safety whilst taking gabapentin. Although serious liver problems are not associated with gabapentin use, certain situations warrant prompt medical attention.

You should contact your GP or healthcare provider if you experience:

• Any symptoms suggestive of liver dysfunction (jaundice, dark urine, pale stools, persistent upper abdominal pain)

• Unexplained and persistent fatigue that interferes with daily activities

• New or worsening swelling of the abdomen

• Easy bruising or bleeding that cannot be explained

• Severe or persistent nausea and vomiting

• Any new symptoms that concern you whilst taking gabapentin

Seek urgent medical attention (contact 999 or attend A&E) if you develop:

• Severe abdominal pain

• Confusion or altered consciousness

• Signs of severe allergic reaction or hypersensitivity (difficulty breathing, severe rash with fever, facial swelling, swollen glands)

• Vomiting blood or passing black, tarry stools

For routine concerns about gabapentin and liver health, schedule an appointment with your GP. They can assess your individual risk factors, review your complete medication list, and arrange appropriate investigations such as liver function tests if clinically indicated. If you have been diagnosed with fatty liver disease or other liver conditions, inform your prescriber so they can consider this in your overall treatment plan.

Patient safety advice:

• Never stop taking gabapentin suddenly without medical advice, as this can cause withdrawal symptoms or seizures in people with epilepsy

• Attend regular medication reviews as recommended by your healthcare team

• Maintain a healthy lifestyle with a balanced diet and regular physical activity to support overall liver health

• Limit alcohol consumption in line with UK Chief Medical Officers' guidelines (no more than 14 units per week, spread over at least three days)

• Keep an up-to-date list of all medications, supplements, and herbal remedies you take

• Do not drive or operate machinery if you feel drowsy, dizzy, or have blurred vision whilst taking gabapentin

• Report any suspected side effects via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or via the Yellow Card app

Your community pharmacist is also an accessible resource for advice about medications and can help address concerns between GP appointments. They can provide information about potential drug interactions and general guidance about safe medication use.

Frequently Asked Questions