New research supported by the National Institutes of Health's National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) shows that the anticonvulsant medication gabapentin, which is used for certain types of seizures, can be an effective treatment for the pain and other symptoms associated with the common, often hard-to-treat chronic pain disorder, Fibromyalgia (FM).

In the NIAMS-sponsored, randomized, double-blind clinical trial of 150 women (90 percent) and men with the condition, Lesley M. Arnold, M.D., director of the Women's Health Research Program at the University of Cincinnati College of Medicine, and her colleagues found that those taking gabapentin at dosages of 1,200 to 2,400 mg daily for 12 weeks displayed significantly less pain than those taking placebo. Patients taking gabapentin also reported significantly better sleep and less fatigue. For the majority of participants, the drug was well tolerated. The most common side effects included dizziness and sedation, which were mild to moderate in severity in most cases.

If you are taking gabapentin for seizures, do not stop taking gabapentin even if you feel better. It is important to continue taking the medication to prevent seizures from recurring.

Carry or wear a medical identification tag to let others know that you are taking this medicine in the case of an emergency.

Use caution when driving, operating machinery, or performing other hazardous activities. Gabapentin may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Take gabapentin exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose of gabapentin with a full glass of water. Gabapentin can be taken with or without food.

To ensure you get the correct dose, measure the gabapentin oral solution with a dose-measuring cup or spoon, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

Carry or wear a medical identification tag to let others know that you are taking this medicine in the case of an emergency.

Do not stop taking gabapentin without talking to your doctor. Suddenly stopping gabapentin may cause side effects. If you are taking gabapentin for seizures, do not stop taking gabapentin even if you feel better. It is important to continue taking the medication to prevent seizures from recurring. Store gabapentin tablets and capsules at room temperature away from moisture and heat. Store the gabapentin oral solution in the refrigerator.

Before taking this medication, tell your doctor if you have any other medical conditions, especially:

• kidney disease
• liver disease
• heart disease

Also discuss any medicines that you take, including over-the-counter preparations. Gabapentin is in the FDA pregnancy category C. This means that it is not known whether gabapentin will be harmful to an unborn baby. Do not take gabapentin without first talking to your doctor if you are pregnant or could become pregnant during treatment. Gabapentin passes into breast milk. Do not take gabapentin without first talking to your doctor if you are breast-feeding a baby.

Take the missed dose as soon as you remember. However, if several hours have passed and it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of the medication to catch up.

Side Effects

Get emergency medical help if you have any of these signs of an allergic reaction:

• skin rash or hives
• difficulty breathing
• swelling of your face, lips, tongue, or throat

Other, less serious side effects may be more likely to occur. Continue to take gabapentin and talk to your doctor if you experience:

• dizziness, poor coordination, or drowsiness
• blurred or double vision
• irregular back-and-forth movements of the eyes
• nausea and vomiting
• tremor

If children 3 to 12 years of age experience any of the following serious side effects, contact your doctor immediately:

• emotional lability (anxiety, behavior problems, crying, etc.)
• hostility (aggressive behavior, suspiciousness, or distrust)
• restlessness, hyperactivity or increase in body movements
• amnesia (loss of memory)
• thought disorders (concentration problems and change in school performance)

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

Gabapentin does not interact with other commonly used antiseizure medications.

Antacids will decrease the amount of gabapentin that is absorbed in the stomach. Do not take gabapentin for at least 2 hours after a dose of antacid.

Gabapentin may increase the effects of other drugs that cause drowsiness, including:

• antidepressants
• alcohol
• antihistamines
• sedatives (used to treat insomnia)
• pain relievers
• anxiety medicines
• muscle relaxants

Drugs other than those listed here may also interact with gabapentin or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including herbal products.