Gabapentin: what it treats, how to take it, side effects
Last updated September 3, 2026.
Gabapentin is an anticonvulsant that calms abnormal excitement in the brain and changes how the body senses pain. You may know it as Neurontin (or Horizant, the extended-release version). It controls seizures and nerve pain rather than curing them.
What does it treat?
Three label jobs: with other medications, controlling certain seizures in epilepsy; relieving postherpetic neuralgia (the burning, stabbing pain that can linger for months after shingles); and, in the extended-release form, restless legs syndrome. Doctors also use it for diabetic neuropathy pain and for hot flashes, per MedlinePlus.
How do you take it?
The capsules, tablets, and oral solution are taken three times a day with a full glass of water, with or without food, evenly spaced - no more than 12 hours between doses. The extended-release tablet is a different animal: once daily with food at about 5 PM, and it cannot be substituted for other gabapentin products. Doses start low and rise gradually - the label's typical nerve-pain start is 300 mg on day one, 600 mg on day two, 900 mg on day three, titrating up as needed. Do not stop suddenly: withdrawal can bring anxiety, insomnia, nausea, pain, and sweating, and stopping seizure treatment cold can bring more seizures - your doctor will decrease the dose gradually over at least a week. Antacids like Maalox or Mylanta go at least 2 hours before gabapentin. Missed dose: take it when you remember unless the next one is close (for the extended-release tablet, skip it); never double up.
Side effects to know
- Common: drowsiness, tiredness or weakness, dizziness, headache, uncontrollable shaking of a body part, double or blurred vision, unsteadiness, anxiety, memory problems, strange or unusual thoughts, unwanted eye movements, nausea, vomiting, heartburn, diarrhea, dry mouth, constipation, increased appetite, and weight gain. Do not drive until you know how it affects you - and alcohol adds to the drowsiness.
- Serious: rash, itching, swelling of the face, throat, tongue, lips, or eyes, hoarseness, and difficulty swallowing or breathing - allergic, immediate call. Difficulty breathing with bluish-tinged skin, lips, or fingernails, confusion, or extreme sleepiness signals dangerous respiratory depression - emergency. And the mental health warning from MedlinePlus: a small number of people (about 1 in 500 in studies) became suicidal on anticonvulsants like gabapentin, sometimes within the first week. Watch for panic attacks, agitation, new or worsening depression or irritability, dangerous impulses, mania, withdrawing from friends and family, preoccupation with death, or giving away prized possessions - and call your doctor right away if they appear.
Who should not take it?
Tell your doctor about lung or kidney disease - kidney problems change the dose, and lung problems raise the breathing risk. NSAIDs like ibuprofen and naproxen can interact. Check that you are not accidentally taking two gabapentin products at once (the forms are not interchangeable). Children on it need watching for mood changes, hostility, hyperactivity, and clumsiness. If you are pregnant, planning pregnancy, or breastfeeding, tell your doctor, and call if you become pregnant while taking it.
When is it an emergency?
Call 911 for trouble breathing, bluish lips or fingernails, extreme sleepiness you cannot be woken from, or facial or throat swelling. If you or someone near you notices talk of self-harm or suicide, call your doctor right away - or call or text 988, the Suicide and Crisis Lifeline, any time. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Why can't I stop gabapentin suddenly?
Withdrawal and rebound. MedlinePlus says stopping suddenly can cause anxiety, insomnia, nausea, pain, and sweating - and if you take it for seizures, stopping cold can make seizures come back more often. The taper is gradual, over at least a week, and your doctor owns the schedule.
Does gabapentin affect mood?
It can, and there is a formal warning. MedlinePlus says about 1 in 500 adults and children in anticonvulsant studies became suicidal, sometimes as early as one week in. The watch list: panic attacks, agitation, new or worsening depression or irritability, dangerous impulses, mania, withdrawal from people, preoccupation with death. Family should know the list too - and call the doctor right away if any of it shows up.
Can I drink alcohol while taking gabapentin?
Bad idea, and MedlinePlus says why: alcohol adds to the drowsiness gabapentin causes. The drug already slows thinking and coordination; alcohol stacks on top and pushes toward dangerous sedation. Ask your doctor, but expect the answer to be skip it.
Why can't I take antacids with gabapentin?
They cut absorption. MedlinePlus says if you take antacids such as Maalox or Mylanta, take them at least 2 hours before gabapentin. Move the antacid, not the gabapentin.
What is the difference between gabapentin and Horizant?
Same ingredient, different release. Regular gabapentin capsules, tablets, and solution go three times a day for seizures and nerve pain. Horizant is the extended-release tablet for restless legs syndrome, taken once daily with food at about 5 PM. MedlinePlus warns the forms cannot be substituted for each other - take exactly the type prescribed.
Is gabapentin addictive?
The sources frame it as dependence-forming rather than addictive: MedlinePlus documents real withdrawal symptoms when it is stopped suddenly - anxiety, insomnia, nausea, pain, sweating - which is why the dose gets tapered over at least a week. Take it exactly as prescribed and never stop on your own.