Gabapentin (patient information)

Why this medication is prescribed

Gabapentin is used to help control certain types of seizures in patients who have epilepsy. Gabapentin is also used to relieve the pain of postherpetic neuralgia (PHN; the burning, stabbing pain or aches that may last for months or years after an attack of shingles). Gabapentin is in a class of medications called anticonvulsants. Gabapentin treats seizures by decreasing abnormal excitement in the brain. Gabapentin relieves the pain of PHN by changing the way the body senses pain.

How this medication should be used

Gabapentin comes as a capsule, a tablet, and an oral solution (liquid) to take by mouth. It is usually taken with a full glass of water (8 oz) three times a day. Gabapentin may be taken with or without food. Take this medication at evenly spaced times throughout the day and night; do not let more than 12 hours pass between doses. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take gabapentin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If your doctor tells you to take one-half of a tablet as part of your dose, carefully split the tablet along the score mark. Use the other half-tablet as part of your next dose. Properly throw away any half-tablets that you have not used within several days of breaking them.

Your doctor will probably start you on a low dose of gabapentin and gradually increase your dose as needed to treat your condition. If you are taking gabapentin to treat PHN, tell your doctor if your symptoms do not improve during your treatment.

Gabapentin may help to control your condition but will not cure it. Continue to take gabapentin even if you feel well. Do not stop taking gabapentin without talking to your doctor. If you suddenly stop taking gabapentin, you may experience withdrawal symptoms such as anxiety, difficulty falling asleep or staying asleep, nausea, pain, and sweating. If you are taking gabapentin to treat seizures and you suddenly stop taking the medication, you may experience seizures more often. Your doctor probably will decrease your dose gradually over at least a week.

Other uses for this medicine

Gabapentin is also sometimes used to relieve the pain of diabetic neuropathy (numbness or tingling due to nerve damage in people who have diabetes), and to treat and prevent hot flashes (sudden strong feelings of heat and sweating) in women who are being treated for breast cancer or who have experienced menopause ( 'change of life', the end of monthly menstrual periods). Talk to your doctor about the risks of using this medication for your condition.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Special precautions

Before taking gabapentin:

• tell your doctor and pharmacist if you are allergic to gabapentin, any other medications, or any of the inactive ingredients in the type of gabapentin you plan to take. Ask your pharmacist for a list of the inactive ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: hydrocodone (in Hydrocet, in Vicodin, others), morphine (Avinza, Kadian, MSIR, others), and naproxen (Aleve, Anaprox, Naprosyn, others). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• if you are taking antacids such as Maalox or Mylanta, take them at least 2 hours before you take gabapentin.
• tell your doctor if you have or have ever had kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking gabapentin, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking gabapentin.
• you should know that this medication may make you drowsy or dizzy. Do not drive a car or operate machinery until you know how this medication affects you.
• if you are giving gabapentin to your child, you should know that your child's behavior and mental abilities may change while he or she is taking gabapentin. Your child may have sudden changes in mood, become hostile or hyperactive, have difficulty concentrating or paying attention, or be drowsy or clumsy. Have your child avoid activities that could be dangerous, such as riding a bicycle, until you know how gabapentin affects him or her.
• remember that alcohol can add to the drowsiness caused by this medication.

Special dietary instructions

Unless your doctor tells you otherwise, continue your normal diet.

What to do if you forget a dose

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Side effects

Minor side effects

Gabapentin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• drowsiness
• tiredness or weakness
• dizziness
• headache
• shaking of a part of your body that you cannot control
• double or blurred vision
• unsteadiness
• anxiety
• memory problems
• strange or unusual thoughts
• unwanted eye movements
• nausea
• vomiting
• heartburn
• diarrhea
• dry mouth
• constipation
• weight gain
• swelling of the hands, feet, ankles, or lower legs
• back or joint pain
• fever
• runny nose, sneezing, cough, sore throat, or flu-like symptoms
• ear pain
• red, itchy eyes (sometimes with swelling or discharge)

Severe side effects

Some side effects may be serious. If you experience any of the following symptoms, call your doctor immediately:

• rash
• itching
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• hoarseness
• difficulty swallowing or breathing
• seizures

Gabapentin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

Storage conditions needed for this medication

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store the tablets and capsules at room temperature, away from excess heat and moisture (not in the bathroom). Store the oral solution in the refrigerator. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Symptoms of overdose may include:

• double vision
• slurred speech
• drowsiness
• diarrhea

Other information

Keep all appointments with your doctor.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking gabapentin.

If you use a dipstick to test your urine for protein, ask your doctor which product you should use while taking this medication.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Gabarone®
• Neurontin®