Is gabapentin bad for your liver?

In this article:

• Is gabapentin hard on the liver?
• Gabapentin and liver disease
• Dosage recommendations
• Alternatives
• The bottom line

In this article

• Is gabapentin hard on the liver?
• Gabapentin and liver disease
• Dosage recommendations
• Alternatives
• The bottom line

Epilepsy and nerve pain can throw a serious wrench into your life—which is why gabapentin is essential for many people. Gabapentin is an anticonvulsant medication that calms nervous system activity, helping prevent or decrease symptoms. While gabapentin has various side effects and precautions, it typically doesn’t affect the liver, although there are rare cases when it might. We’ve got everything you need to know below. 

Is gabapentin hard on the liver? 

Nearly half of all liver failure cases are caused by drug-induced liver injury, according to 2014 research in Clinical Liver Disease. So it’s natural to be concerned about it. However, most people taking gabapentin can put their minds at ease since it rarely harms the liver.

Gabapentin is considered an analogue for the neurotransmitter gamma-aminobutyric acid (GABA), which blocks certain signals to the brain, slowing down the nervous system. Even though the liver contains GABA—and GABA has some positive hepatic effects—gabapentin rarely reaches it.

That’s why “gabapentin is not known to have any effect on the liver, and if it were to, it would be rare and completely unexpected,” psychiatrist Dr. Cooper Stone, MD. “The reason for this is that gabapentin is not metabolized by the liver like most drugs, instead it is simply cleared from the body unmetabolized by the body’s kidneys.”

That said, there have been some case reports that showed gabapentin-induced liver issues. One 2018 study published in Cureus, for example, found liver injury in a 67-year-old gabapentin patient who had no other known cause for it. But this uncommon side effect isn’t just confined to older adults—a 2022 study from The American Journal of Gastroenterology reported gabapentin-induced hepatotoxicity in a 41-year-old as well. These cases are the exception, not the rule, but it’s still important to know it’s possible.

Typically, doctors use a blood test to evaluate liver health and potential injury, and these tests measure enzymes, a byproduct of red blood cells called bilirubin, and a type of white blood cell called eosinophils. Gabapentin use isn’t known to affect enzyme or bilirubin levels, but it may rarely cause an allergic reaction characterized by elevated eosinophil levels. This is a condition called eosinophilia, which may cause liver damage. In certain cases, drug reactions with eosinophilia and systemic symptoms (DRESS) can even be life-threatening—both those cases are rare. 

Can you take gabapentin if you have liver disease?

Since the liver doesn’t metabolize gabapentin, it’s typically safe for people who have cirrhosis or other liver diseases. In fact, a study from the Journal of Gastroenterology & Hepatology concluded that cirrhotic patients might tolerate gabapentin better than other analgesics for post-surgical pain.

Yet there’s still a small chance that liver issues can affect gabapentin’s effects. “Periodically those with liver disease may experience an acute worsening of their liver, which, for some, can result in an accumulation of toxic chemicals in the body. This accumulation may then lead to changes in one’s cognition, cause confusion, and other such unwanted effects, all of which can be worsened when combined with gabapentin,” Dr. Stone says.

However, he continues, “This effect is not exclusive to gabapentin and can be seen with other medications such as muscle relaxers, benzodiazepines, opioids, etc. It is important to note just because one may have liver disease does not mean they cannot necessarily be on these or other medications.”

It’s a somewhat different story for people with kidney disease, though. Gabapentin doesn’t directly damage the kidneys, but because the body excretes it through the kidneys, reduced renal function might make it harder to clear. That’s why doctor’s will often adjust the dose of gabapentin or consider alternatives for people with significant kidney dysfunction.

Regardless of liver and kidney health, gabapentin may cause certain side effects. According to the clinical trials outlined on Neurontin’s label, the most common side effects of gabapentin for people with postherpetic neuralgia are dizziness, drowsiness, and peripheral edema. For adults with epilepsy, the most common are drowsiness, dizziness, ataxia, fatigue, and uncontrolled eye movements. And for children with epilepsy, the most common are viral infection, fever, nausea/vomiting, drowsiness, and hostility.

Safe gabapentin dosages for people with liver disease

As we mentioned above, gabapentin is generally safe for people who have liver disease, so prescribers often use the standard dose. According to the NIH, those gabapentin doses are:

• For partial seizures: 300–1200 mg, 3 times/day, with a maximum daily dosage of 3600 mg.
• For postherpetic neuralgia: 300–600 mg, 3 times/day, with a maximum daily dosage of 1800 mg.
• For restless legs syndrome: 600 mg, once daily, with a maximum daily dosage of 1800 mg.
• For neuropathic pain: 300–1200 mg, 3 times/day, with a maximum daily dosage of 3600 mg.

• For fibromyalgia: 400–800 mg, 3 times/day, with a maximum daily dosage of 2400 mg.

Some of those are fairly wide ranges, and that’s because gabapentin dosage depends on a few factors. The prescribing doctor chooses the dosage based on a patient’s weight, other medications, age, general health, and other medical conditions. “Typically speaking, it’s better to start with a low dose and adjust gradually while keeping a close eye on how the patient is responding,” says Dr. Misbah Sadiq, psychiatrist at Asana Lodge.

If your doctor is concerned about your hepatic function during gabapentin treatment, they will likely order liver panel tests to monitor it. These blood tests measure the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP), along with albumin and bilirubin. The frequency of these tests depends on the nature of your doctor’s concerns, and labs may be ordered after an increase in the gabapentin dose.

Alternatives to gabapentin

Even though gabapentin is typically safe for the liver, the rare cases of hepatotoxicity might be a dealbreaker for certain patients. The good news is that it’s far from the only medication for epilepsy and nerve pain. Some alternatives include:

• Other anticonvulsants: Belonging to the same drug class as gabapentin, Lyrica (pregabalin), Tegretol (carbamazepine), and Trileptal (oxcarbazepine) can also treat epilepsy and nerve pain.
• Tricyclic antidepressants: Research has shown that drugs like amitriptyline, nortriptyline, and desipramine are often effective for neuropathic pain.
• Serotonin-norepinephrine reuptake inhibitors (SNRIs): Another drug class that’s shown promise in treating nerve pain, these are medications like Cymbalta (duloxetine) and Effexor (venlafaxine).
• Benzodiazepines: Studies also show that these drugs—like Klonopin and Valium—are viable options for seizures. However, “benzodiazepines in nearly all cases should be used extremely sparingly, at the lowest effective dose possible, and for the shortest time possible given the high risk of dependency, side effects, and potentially fatal withdrawal if not tapered under medical supervision,” Dr. Stone says. 
• Barbituates: Drugs like phenobarbital have declined in popularity for seizure treatment over the years, but studies still back up their effectiveness. They are considered a controlled drug and are known to be addictive. 

• Topical anesthetics: While they aren’t as intensive as prescription medications, over-the-counter topical creams and patches like lidocaine and capsaicin may help with nerve pain, according to some research.
• Opioids: Drugs like oxycodone might be effective for some types of nerve pain, but they can also have serious adverse effects, specifically addiction and abuse.

While there are plenty of options, the reality is that there’s no overarching, risk-free supercure that works perfectly for everyone. That’s why it’s important for each patient to consult a healthcare provider about their unique conditions, medical history, other medications, and preferences. Additionally, “collaborating with hepatologists or gastroenterologists is also essential for managing more complex cases,” Dr. Sadiq says.

The bottom line

Although there have been some recorded cases of hepatotoxicity during gabapentin treatment, it’s typically a safe option for most people with epilepsy or nerve pain. It’s eliminated by the kidneys, not the liver, so it only negatively interacts with the liver in rare circumstances. Still, getting medical advice from a doctor before taking it is crucial since they can evaluate your liver health, choose the ideal dosage, and monitor your symptoms and overall health throughout the process.