Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them.

The table below contains some of the most common ones associated with gabapentin.

You will find a full list in the manufacturer’s information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common gabapentin side-effects
What can I do if I experience this?
Feeling sleepy, tired, unsteady or dizzy; blurred vision and other eyesight problems Do not drive or use tools or machines
Headache Ask your pharmacist to recommend a suitable painkiller
Feeling or being sick, indigestion, stomach ache Stick to simple foods – avoid rich or spicy meals
Diarrhoea Drink plenty of water to replace the lost fluids
Constipation Try to eat a well-balanced diet and drink several glasses of water each day
Dry mouth Try chewing sugar-free gum or sucking sugar-free sweets
Infections, flu-like symptoms, increased appetite, flushing,
increased blood pressure, changes in weight, changes in emotions or mood, fits, movement difficulties, feeling shaky, difficulties sleeping, breathing difficulties, cough, gum changes, bruises, muscle or joint pains, impotence, and swollen feet or ankles
If any of these become troublesome, speak with your doctor for advice

Important: gabapentin has been associated with a number of unwanted effects which affect the blood, pancreas and liver.

Although these occur less commonly than the side-effects listed above, you must let your doctor know straightaway if you notice any of the following as they could be serious:

    • Persistent stomach pain with sickness (these could be symptoms of an inflamed pancreas).
    • A skin rash, or any swelling of your mouth or face (these could be symptoms of an allergic reaction).
    • Any yellowing of your skin or of the whites of your eyes (these could be symptoms of jaundice).
    • Any unusual bruising or bleeding (these could be symptoms of a blood disorder).

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.