Neurontin (gabapentin) seldom causes problems from side effects. People who do report side effects most often mention:

• tiredness
• sleepiness
• dizziness
• weight gain
• ankle swelling

These effects usually are mild and tend to improve after several weeks:

• headache
• unsteadiness
• double vision
• tremor
• stomach upset
• behavioral problems such as irritability and hyperactivity (in children, especially those with pre-existing behavioral disturbances)

If you notice problems like any of these while you are taking Neurontin, it's probably a good idea to discuss them with your doctor or nurse. Don't stop taking Neurontin or any other seizure medicine without the doctor's advice. Sometimes the doctor can help with these side effects by changing the prescription:

• reducing the overall amount
• prescribing smaller doses, to be taken more often
• changing the amount taken at certain times, such as taking a greater proportion at bedtime to reduce daytime sleepiness

Some people who take Neurontin actually experience beneficial effects on mood and emotional well-being. Doctors are exploring whether it can be used to treat disorders like depression and anxiety. Preliminary evidence suggests that Neurontin may help to stabilize mood in bipolar (manic-depressive) disorder and social phobia, a type of anxiety disorder. No problems with memory or learning have been observed.

Allergic reactions
There do not appear to be any allergic reactions to Neurontin.

Long-term side effects
The long-term side effects of Neurontin are not known.