Gabapentin

Key facts

• Gabapentin is an anticonvulsant used alongside other medicines to control certain types of seizures, and it is also used to treat nerve pain, such as pain after shingles and diabetic nerve pain, and restless legs syndrome.
• It is taken by mouth, usually starting at a low dose that is increased gradually; relief from nerve pain can take days to weeks to become noticeable.
• Combining gabapentin with opioids, benzodiazepines, alcohol, or other medicines that slow breathing can cause life-threatening, sometimes fatal, respiratory depression. The risk is highest in older adults and people with lung disease.
• Seek urgent care for slow or shallow breathing, extreme drowsiness, difficulty waking up, or unresponsiveness.

What gabapentin treats

Gabapentin is used as add-on treatment for partial (focal) seizures in epilepsy, for neuropathic pain such as postherpetic neuralgia (pain that lingers after shingles) and diabetic peripheral neuropathy, and for restless legs syndrome. It is not an effective treatment for general or acute pain unrelated to nerve damage.

How gabapentin works

Gabapentin is structurally similar to the brain chemical GABA, but it does not act on GABA receptors. Instead, it binds to a subunit of voltage-gated calcium channels on nerve cells, which reduces the release of excitatory neurotransmitters. This calms the overactive nerve signaling responsible for seizures and for the pain of damaged nerves.

Before you take it

• Tell your prescriber about kidney disease, since the dose needs to be adjusted, and about any history of substance misuse, depression, or breathing problems such as COPD or sleep apnea.
• Avoid alcohol and use caution with other sedating medicines, including opioids, benzodiazepines, sleeping tablets, and some antihistamines. Combined effects on breathing and alertness can be dangerous.
• Do not stop gabapentin suddenly. Abrupt withdrawal can cause anxiety, insomnia, sweating, and, in people with epilepsy, rebound seizures. Your prescriber will lower the dose gradually.
• Gabapentin has a recognized potential for misuse and dependence, particularly in people with a history of substance use disorder. Use it only as prescribed.

Side effects

Common effects include drowsiness, dizziness, fatigue, unsteady walking, blurred vision, and swelling of the hands or feet. These are usually more noticeable when the dose is increased.

Seek urgent care for:

• Slowed or difficult breathing, especially if combined with other sedating medicines.
• Severe drowsiness or confusion, or difficulty waking up.
• Rash, facial swelling, fever with swollen glands, or other signs of a serious allergic reaction.
• New or worsening suicidal thoughts or significant mood changes.

Safety essentials

• Never combine gabapentin with opioids or other central nervous system depressants without medical supervision. This combination is a well-recognized cause of fatal overdose, and the risk is greatest in elderly people and those with existing lung disease.
• Do not stop gabapentin abruptly. Always taper the dose under medical guidance to avoid withdrawal symptoms or seizures.
• Store it securely and never share it with anyone else, given its potential for misuse.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.