Gabapentin

Sounds like 'gab-a-pen-tin'

Easy-to-read medicine information about gabapentin – what it is, how to take gabapentin safely and possible side effects.

Type of medicine Also called
  • Pain medication 
  • Anticonvulsant (to treat epilepsy)
  • Neurontin®
  • Nupentin®
  • Arrow-Gabapentin®

What is gabapentin?

Gabapentin works by changing the way that nerves send messages to your brain. It has many uses:

  • for the relief of nerve pain (also called neuropathy). Nerve pain occurs when damage or changes to your nerves through injury or disease such as diabetes or shingles, causes them to misfire and send pain signals to the brain. Read more about nerve pain
  • to treat epilepsy by preventing some types of seizures
  • to prevent attacks of migraine if other medicines are not suitable. 

In New Zealand, gabapentin is available as capsules. 

Dose

  • The dose of gabapentin will be different for different people. Your doctor will usually start you on a low dose and increase the dose over a few days. This allows your body to get used to the medicine and reduces the chances of side effects.
  • Most people take 3 doses a day once they are on a regular dose. 
  • Always take your gabapentin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much gabapentin to take, how often to take it, and any special instructions.  
My dose is:

Date Morning Lunch Night
       
       
       
       
Notes:



How to take gabapentin

  • Take gabapentin at the same times each day.
  • Swallow gabapentin with a glass of water.
  • You can take gabapentin with or without food. Try taking gabapentin with food if it makes you feel sick (nausea).
  • Limit or avoid alcohol while taking gabapentin. Taking gabapentin and alcohol can make your more sleepy, drowsy or dizzy.
  • There are many strengths of gabapentin capsules available. Check the strength of the capsules each time you get a new prescription to make sure they are what you are expecting.
  • If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the amount.
  • If you are taking gabapentin for pain, it will not relieve pain immediately – it may take a few days before you start noticing a reduction in pain.
  • If you think gabapentin is not working for you, do not stop taking it suddenly; speak to your doctor or nurse before stopping. It is usually best to stop taking gabapentin slowly to avoid side effects.

Precautions – before starting gabapentin

  • Do you have kidney problems?
  • Do you have problems with your heart?
  • Do you have diabetes?
  • Have you had any psychotic episodes?
  • Are you pregnant or breast feeding?
  • Are you taking any other medicines? This includes any medicines you buy without a prescription, such as herbal and complementary medicines.

If so, it’s important that you tell your doctor or pharmacist before you start gabapentin. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Possible side effects

Like all medicines, gabapentin can cause side effects, although not everyone gets them. Often side effects improve as your body adjusts to the new medicine.

Problems with balance and drowsiness

This is quite common when you start taking gabapentin. Up to 1 in 3 people experience dizziness or drowsiness.

  • Be careful when driving or using tools until you know how this medicine affects you.
  • Also be careful when getting up from either lying down or sitting – the loss of balance and dizziness can put you at risk of falls and injuries, especially if you are elderly.
  • Avoid drinking alcohol while you are taking gabapentin. This can make dizziness and drowsiness worse. 

Tell your doctor if these side effects are troublesome – you may need a lower dose.

Other side effects

Side effects What should I do?
  • Stomach upset, feeling sick (nausea)
  • Try taking gabapentin with food.
  • Tell your doctor if troublesome.
  • Weight gain 
  • This is quite common in the first few months of starting gabapentin.
  • Most people gain less than 2 kilograms, but up to 15% of people, depending on dose, can gain over 5 kilograms.
  • Follow a healthy diet and exercise regularly.
  • Headache 
  • This may go away with time.
  • Tell your doctor if troublesome.
  • Ankle or leg swelling
  • This is more common in elderly people or if you are taking higher doses.
  • Tell your doctor.
  • Frequent mood changes, depression, or worsening depression, aggressive tendencies, thoughts of suicide, and abnormal behaviours
     
  • Tell your doctor immediately or ring HealthLine 0800 611 116.
  • Signs of an allergy such as skin rash, fever, flu-like symptoms, breathing difficulties.
  • Tell your doctor immediately or ring HealthLine 0800 611 116.

Interactions

Gabapentin interacts with a number of medications and herbal supplements so check with your doctor or pharmacist before starting gabapentin or before starting any new medicines. Do not take antacid preparations during the 2 hours before you are due to take gabapentin, or during the 2 hours after you have taken a dose.

Learn more

Medsafe Consumer Information Sheet: Neurontin; Nupentin 
New Zealand Formulary Patient Information: Gabapentin

References

  1. Prescribing gabapentin and pregabalin: upcoming subsidy changes BPAC, 2018
  2. Managing patients with neuropathic pain BPAC, 2016
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 17 Apr 2018