Gabapentin

(gab-uh-PEN-tin)

Trade/other name(s): Neurontin

Why would this drug be used?

Gabapentin is used as a non-opioid pain reliever. It belongs to a general class of drugs called anticonvulsants (anti-seizure drugs). It is given along with pain medicines to help control neuropathic pain (numbness, tingling, burning, shooting, or electric-shock-like pain). It is also used to help prevent seizures and for other purposes.

How does this drug work?

Some studies suggest that it reduces the pain response, but exactly how it works is still unknown.

Before taking this medicine

Tell your doctor…

• If you are allergic to anything, including medicines, dyes, additives, or foods.
• If you have kidney disease. Your dose may need to be reduced.
• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. There may be an increased risk of harm to the fetus if a woman takes this drug during pregnancy. If the drug is taken during pregnancy, the mother should be on a pregnancy registry so that the baby can be observed for any abnormalities.
• If you are breast-feeding. The drug passes into breast milk and can affect the baby.
• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Morphine may increase gabapentin levels and increase risk of side effects. If you need to be on both of these, the doctor may be able to lower your dose of gabapentin to reduce this risk.

The anti-inflammatory pain reliever naproxen increases the amount of gabapentin the body absorbs. Talk with your doctor if you take this medicine.

When gabapentin is taken along with hydrocodone, it lowers hydrocodone levels, while gabapentin levels go higher. Talk with your doctor about this if you are taking both drugs.

Medicines that slow down the brain or nervous system, such as other pain relievers, tranquilizers, sedatives, sleeping pills, antidepressants, muscle relaxers, antihistamines, phenothiazines, anesthetic medicines, and alcohol can cause worse side effects, such as reduced alertness, sleepiness, and similar effects if taken with gabapentin.

Antacids reduce the amount of gabapentin your body can absorb. Take gabapentin at least 2 hours after taking antacids.

Check with your doctor, nurse, or pharmacist about whether other medicines, vitamins, herbs, and supplements can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time, although alcohol can worsen side effects. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Gabapentin comes in a capsule or liquid form which is taken by mouth with or without food, with a glass of water, usually 3 times a day. The dose depends largely on how much you need to control the pain. The dose is usually started low and gradually increased over about 3 days until an effective dose is reached. Take this drug exactly as instructed by your doctor.

If you break a tablet in half for a dose, take the other half at your next dose. Discard broken tablets after a few days.

If you do not understand the directions for taking this drug, ask your doctor or nurse to explain them to you.

Store the medicine in a tightly closed container away from heat and moisture and out of the reach of children and pets. Keep liquid gabapentin in the refrigerator. Do not freeze.

Precautions

This medicine can cause drowsiness, clumsiness, and trouble walking. Do not drive, operate machinery, or perform other activities that require mental alertness and physical coordination until you know how you react to this medicine.

Since gabapentin affects the brain and nervous system, it is important not to take other drugs or substances that slow down the brain or nervous system such as alcohol, sedatives, muscle relaxers, and sleeping medicines unless your doctor tells you to do so.

Call your doctor right away if you notice any rash or hives, especially if you also have swelling of the mouth or throat, or flu-like symptoms such as fever and muscle pain. Sometimes a person who is sensitive (allergic) to gabapentin will also have swollen lymph nodes, which may progress to fever, rash, and effects on other organs of the body. The reaction may even include yellow skin or eyes, bruising, bleeding, or fatigue. Any of these can be signs of a serious reaction that can result in death, so call your doctor without delay.

If you notice any strange or unusual thoughts or behavior while on this medicine, call your doctor. Some people think about suicide and may hurt themselves. Rarely, people get confused, agitated, or start seeing or hearing things that are not there. Tell family members, loved ones, and caregivers that you are taking this drug, so that they can help you if they notice behavior changes.

Call your doctor or nurse right away if you have trouble walking, talking, breathing, or passing your urine, or if you notice confusion, changes in your eyes or vision, or any other problems taking the drug.

If you have ever had seizures, do not stop the medicine suddenly without talking with your doctor. Your dose may need to be tapered down over about a week to prevent seizures.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.

Common

• sleepiness*
• dizziness*
• tiredness (fatigue)

Less common

• trouble walking*
• swelling or numbness in the hands or feet
• tremors
• nervousness
• trouble talking*
• amnesia or lost memory
• headache
• mood swings
• decreased reflexes
• irritability
• heartburn
• rash, sometimes severe, with flu-like symptoms, sores in mouth or on lips*
• hair thinning

Rare

• blurred or double vision, eye problems*
• increased sensitivity to sunlight
• constipation
• nausea, vomiting
• thirst, dry mouth
• increased saliva in the mouth
• cough
• nosebleeds
• change in blood pressure
• chest pain
• dry eyes
• hearing loss
• change in appetite and taste
• runny nose
• depression
• confusion
• trouble breathing*
• trouble passing your urine*
• changes in sexual functioning
• faster heart rate
• breast enlargement in men
• swelling of the face
• seizures if drug is stopped suddenly (if drug is being used to control seizures)*
• sensitivity or allergy involving more than one organ*
• suicidal thoughts or actions
• death due to sensitivity (allergy) to the drug*

*See "Precautions" section for more detailed information.

There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA Approval

Yes – first approved in 1993.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.