What are the side effects of gabapentin?

Gabapentin is an anticonvulsant medication that doctors often prescribe to prevent seizures in people with epilepsy. It is not a cure for epilepsy, but it can help people manage the condition. Gabapentin is generally safe, but it can cause side effects, some of which may require medical attention.

In this article, we look at the potential side effects of gabapentin and whether or not they differ between men and women. We also cover when to see a doctor.

What is gabapentin?

close up of woman taking a tablet
Gabapentin is a prescribed anticonvulsant and is available in many forms.

Gabapentin is an anticonvulsant medication that doctors prescribe as an epilepsy treatment to prevent partial seizures.

Gabapentin cannot cure epilepsy, but it helps the brain prevent seizures. This drug can also act as a pain reliever for various conditions that affect the nervous system, such as postherpetic neuralgia, a pain that occurs due to shingles.

However, doctors do not prescribe gabapentin to treat arthritis pain or acute pain that results from minor injuries.

Gabapentin is only available with a doctor’s prescription, and it comes in the following forms:

  • capsule
  • tablet
  • solution
  • suspension

Common side effects

Gabapentin is a fairly safe medication when people take it according to a doctor’s instructions. However, some people may experience side effects.

Common side effects that generally do not require medical attention include:

  • blurred vision
  • cold or flu-like symptoms
  • delusions
  • dementia
  • hoarseness
  • lack or loss of strength
  • pain in the lower back or side
  • swelling of the hands, feet, or lower legs
  • trembling or shaking

Common side effects that do require medical attention include:

  • back-and-forth or rolling eye movements that are continuous and uncontrolled
  • unsteadiness

Gabapentin can cause different side effects in children that may require medical attention. These include:

  • aggressive behavior or other behavioral problems
  • anxiety
  • change in school performance
  • concentration problems
  • crying
  • depression
  • distrust
  • false sense of well-being
  • hyperactivity or increase in body movements
  • rapidly changing moods
  • reacting too quickly or overreacting
  • restlessness

Long-term effects

According to the authors of a 2010 study paper, people with preexisting kidney disease may experience potentially fatal toxicity when taking gabapentin.

Gabapentin may cause other long-term effects, including memory loss, weakened muscles, and respiratory failure.

Rare side effects

man with chest pain
Chest pains can be a rare side effect of taking gabapentin.

Other side effects of gabapentin occur less frequently but may still affect some people.

Rare side effects that are unlikely to need medical attention include:

  • a sore throat
  • black stools
  • chest pain
  • chills
  • coughing
  • depression, irritability, or other mood changes
  • fever
  • memory loss
  • pain or swelling in the legs or arms
  • painful or difficult urination
  • shortness of breath
  • sores, white spots, or ulcers on the lips or in the mouth
  • swollen glands
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Side effects that require medical attention include:

  • a feeling of warmth or heat
  • a runny nose
  • accidental injury
  • an earache
  • back pain
  • bloating
  • body aches or pain
  • breath that smells fruity
  • burning, dry, or itchy eyes
  • changes in vision
  • clumsiness or unsteadiness
  • congestion
  • constipation
  • coughing that produces mucus
  • decreased sexual desire or ability
  • difficulty breathing
  • difficulty swallowing
  • dry skin
  • dryness of the mouth or throat
  • ears ringing
  • excess air or gas in the stomach or intestines
  • excessive tearing of the eyes
  • eye discharge
  • feeling faint, dizzy, or lightheaded
  • flushing or redness of the skin, especially on the face and neck
  • frequent urination
  • higher sensitivity to pain and touch
  • impaired vision
  • increased appetite
  • increased thirst
  • indigestion
  • lack of coordination
  • pain, redness, rash, swelling, or bleeding in areas where the skin rubs
  • passing gas
  • problems with walking and balance
  • redness or swelling in the ear
  • redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
  • sleep problems
  • sneezing
  • sweating
  • tender, swollen glands in the neck
  • tightness in the chest
  • tingling in the hands and feet
  • trouble processing thoughts
  • twitching
  • unexplained weight loss
  • voice changes
  • vomiting
  • weakness or loss of strength
  • weight gain

Does gabapentin affect men and women differently?

There is a lack of scientific research comparing the effects of gabapentin in men and women. However, the 2011 drug label for the Neurontin brand of gabapentin, which the United States Food and Drug Administration (FDA) approved, states that “there are no significant gender differences.”

The only difference between men and women may relate to sexual dysfunction. According to an article in The American Journal of Psychiatry, both men and women may lose the ability to orgasm after taking gabapentin. However, only women have also reported experiencing a lack of libido.

A more recent study confirms this possible side effect at doses of only 300 milligrams per day.

When to see a doctor

gabapentin capsules
A doctor can prescribe gabapentin and give advice on side effects.

Gabapentin is only available on prescription, so people will need to visit a doctor to obtain this medication.

It is vital to discuss the potential side effects of gabapentin, as well as any necessary precautions, with the doctor. They are likely to:

  • offer dietary and lifestyle advice, particularly if weight gain from gabapentin is a concern
  • advise the individual not to drive or operate heavy machinery while taking gabapentin
  • recommend over-the-counter medications that can help with some common side effects

People already taking the medication should visit a doctor if the side effects become bothersome. It is important not to stop gabapentin treatment without speaking with a doctor first. Suddenly stopping the drug can lead to withdrawal, seizures, and other serious problems.

A doctor can offer advice on managing side effects and provide medical supervision to allow a person to start or stop taking the medicine safely.