Does gabapentin cause weight gain?

Gabapentin may cause weight gain, but it is a rare side effect. Gabapentin is used to treat epilepsy.

It’s also taken for nerve pain, which can be caused by different conditions, including diabetes and shingles. Nerve pain can also happen after an injury.

In epilepsy, it’s thought that gabapentin stops seizures by reducing the abnormal electrical activity in the brain.

With nerve pain, it’s thought to block pain by affecting the pain messages travelling through the brain and down the spine.

Gabapentin is available on prescription. It comes as tablets, capsules and a liquid that you swallow.

Studies have shown that a small number of people taking gabapentin, a drug used to treat epilepsy and postherpetic neuralgia, experienced weight gain. People who do gain weight may gain about 5 pounds after 6 weeks of use.

    • In people with epilepsy, weight gain occurred in 3% of people older than 12 years of age who were taking gabapentin (compared to 2% of people taking the placebo). Weight gain was also seen at a similar rate in pediatric epilepsy patients who were 3 to 12 years old.
    • In people with postherpetic neuralgia, 2% of patients taking gabapentin experienced weight gain. No weight gain was found among people taking the placebo.

The cause of weight gain with gabapentin is likely due to increased appetite. You may be hungry more often. In some cases, weight gain may be due to fluid retention, another side effect of gabapentin. Another possible cause is not getting enough exercise if gabapentin is causing fatigue.

Some ways to avoid weight gain include:

    • Eating a healthy and balanced diet
    • Eating smaller portion sizes
    • Avoiding high-calorie snacks and desserts like chips, pastries and sweets
    • Eating low-calorie snacks like fruits and vegetables to manage hunger
    • Getting regular exercise

Swelling from fluid retention may be reduced by:

    • Sitting with your feet raised
    • Avoiding standing for long periods of time

If gabapentin is causing you to gain weight, do not stop taking this drug on your own. Stopping the drug suddenly can lead to serious problems, especially if you are taking gabapentin for seizures. Abruptly stopping a seizure medicine can cause seizures that won’t stop.

Weight gain is one of many possible side effects. The most common side effects with gabapentin include:

    • Clumsiness
    • Viral infection
    • Sleepiness
    • Nausea and vomiting
    • Speaking difficulties
    • Tremor
    • Swelling, usually involving the legs and feet
    • Fatigue
    • Fever
    • Movements that are jerky
    • Coordination difficulties
    • Double vision
    • Unusual eye movement

Detail Side Effects of Gabapentin

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

    1. Clumsiness or unsteadiness
    2. continuous, uncontrolled, back-and-forth, or rolling eye movements

More common in children

    1. Aggressive behavior or other behavior problems
    2. anxiety
    3. concentration problems and change in school performance
    4. crying
    5. depression
    6. false sense of well-being
    7. hyperactivity or increase in body movements
    8. rapidly changing moods
    9. reacting too quickly, too emotional, or overreacting
    10. restlessness
    11. suspiciousness or distrust

Less common

    1. Black, tarry stools
    2. chest pain
    3. chills
    4. cough
    5. depression, irritability, or other mood or mental changes
    6. fever
    7. loss of memory
    8. pain or swelling in the arms or legs
    9. painful or difficult urination
    10. sore throat
    11. sores, ulcers, or white spots on the lips or in the mouth
    12. swollen glands
    13. unusual bleeding or bruising
    14. unusual tiredness or weakness

Incidence not known

      1. Abdominal or stomach pain
      2. blistering, peeling, or loosening of the skin
      3. clay-colored stools
      4. coma
      5. confusion
      6. convulsions
      7. dark urine
      8. decreased urine output
      9. diarrhea
      10. difficult or troubled breathing
      11. dizziness
      12. fast or irregular heartbeat
      13. headache
      14. increased thirst
      15. irregular, fast or slow, or shallow breathing
      16. itching or skin rash
      17. joint pain
      18. large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
      19. loss of appetite
      20. muscle ache or pain
      21. nausea
      22. pale or blue lips, fingernails, or skin
      23. red skin lesions, often with a purple center
      24. red, irritated eyes
      25. unpleasant breath odor
      26. vomiting of blood
      27. yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Blurred vision
  2. cold or flu-like symptoms
  3. delusions
  4. dementia
  5. hoarseness
  6. lack or loss of strength
  7. lower back or side pain
  8. swelling of the hands, feet, or lower legs
  9. trembling or shaking

Less common or rare

  1. Accidental injury
  2. appetite increased
  3. back pain
  4. bloated or full feeling
  5. body aches or pain
  6. burning, dry, or itching eyes
  7. change in vision
  8. change in walking and balance
  9. clumsiness or unsteadiness
  10. congestion
  11. constipation
  12. cough producing mucus
  13. decrease in sexual desire or ability
  14. dryness of the mouth or throat
  15. earache
  16. excess air or gas in the stomach or intestines
  17. excessive tearing
  18. eye discharge
  19. feeling faint, dizzy, or lightheadedness
  20. feeling of warmth or heat
  21. flushed, dry skin
  22. flushing or redness of the skin, especially on the face and neck
  23. frequent urination
  24. fruit-like breath odor
  25. impaired vision
  26. incoordination
  27. increased hunger
  28. increased sensitivity to pain
  29. increased sensitivity to touch
  30. increased thirst
  31. indigestion
  32. noise in the ears
  33. pain, redness, rash, swelling, or bleeding where the skin is rubbed off
  34. passing gas
  35. redness or swelling in the ear
  36. redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
  37. runny nose
  38. sneezing
  39. sweating
  40. tender, swollen glands in the neck
  41. tightness in the chest
  42. tingling in the hands and feet
  43. trouble sleeping
  44. trouble swallowing
  45. trouble thinking
  46. twitching
  47. unexplained weight loss
  48. voice changes
  49. vomiting
  50. weakness or loss of strength
  51. weight gain

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

How long does it take gabapentin to work?

It can take several weeks for gabapentin to reach its full effect, but this depends on the condition being treated.

Gabapentin is approved to treat:

      • Nerve pain
      • Some types of seizures
      • Restless legs syndrome (RLS)

It also depends on your individual response to the drug. The time gabapentin takes to work is not the same for everyone.

The effective dose of gabapentin is also very different for each person. It may vary from 300 mg per day to up to 3,000 mg per day.

Another reason gabapentin takes time to work is that the dose is usually started low and gradually increased over time to reach an effective dose.

For example, when used to relieve nerve pain, the initial dose may be started at 300 mg and increased by 300 mg daily over several days, gradually reaching up to 600 mg three times per day. Studies for nerve pain treatment show that pain relief may begin within 1 week, with the maximum effect reached after about 4 weeks.

Gabapentin is in a class of medications called anticonvulsants. It is not completely known how this drug works. When used to treat a type of seizure disorder, called a partial onset seizure, gabapentin decreases the abnormal activity in the brain that causes the seizures. When used to treat nerve pain, or neuralgia, following a herpes zoster (shingles) infection, gabapentin may reduce the response to painful stimuli. It is unknown how gabapentin relieves symptoms of restless legs syndrome.

Even though it may take up to 4 weeks to get the full effects of gabapentin, it is important not to stop taking it suddenly. That could cause withdrawal symptoms such as:

      • Anxiety
      • Insomnia
      • Nausea
      • Pain

If you are taking gabapentin to control seizures, stopping suddenly may increase your risk of a seizure.

Common side effects of Gabapentin

These common side effects of gabapentin may happen in more than 1 in 100 people. They’re usually mild and go away by themselves.

There are things you can do to help cope with them:

    • Feeling sleepy, tired or dizzy
    • Feeling sick (nausea)
    • Being sick (vomiting)
    • Diarrhoea
    • Mood changes
    • Swollen arms and legs
    • Blurred vision
    • Dry mouth
    • Difficulty getting an erection
    • Weight gain
    • Memory problems
    • Headaches
    • Getting more infections than usual

Keep taking the medicine, but talk to your doctor if this advice does not help and the side effects bother you or do not go away.

 

Is gabapentin considered a painkiller?

Gabapentin is commonly used to treat some types of nerve pain but is classified as an anticonvulsant medicine, not as an opioid or painkiller.

Gabapentin was first approved in 1993 and is used to treat:

    • postherpetic neuralgia, a nerve pain caused by the shingles virus (herpes zoster),
    • restless legs syndrome (RLS), a painful movement disorder in the legs
    • partial seizures in adults and children at least 3 years old who have epilepsy

Gabapentin works by affecting chemicals and nerves in the body that are involved in the cause of seizures and in some types of nerve pain.

Gabapentin is not a federally-controlled drug substance and does not contain an opioid (narcotic) medication. However, gabapentin misuse and abuse has been reported, and it may be restricted in some states through their state drug-monitoring program. Gabapentin abuse can boost the high a person gets from opioid painkillers, muscle relaxants, and anxiety medications. This can be dangerous and potentially life-threatening.

In 2019, the FDA issued an alert that serious breathing problems have been reported with gabapentin and other related drugs, like Lyrica (pregabalin) in people at risk of slowed breathing.

    • This includes people who use opioid pain medicine or CNS depressants, people with chronic obstructive pulmonary disease (COPD, and the elderly.
    • These serious breathing problems may be fatal.
    • Read more about this serious FDA warning here.

Avoid or limit the use of alcohol (in beverages or medicines) with gabapentin as it can worsen drowsiness or dizziness. Ask you doctor about drinking alcohol while you are taking gabapentin.

What type of pain does gabapentin treat?

Gabapentin is approved by the FDA to treat:

Postherpetic neuralgia: nerve pain that can occur due to an outbreak of shingles. Shingles, also known as herpes zoster, occurs when the chicken pox virus deep-seated in your nerve activates again later in life and causes a serious skin rash. Not everyone gets postherpetic neuralgia from shingles, but it can be painful if you do. It causes a burning nerve pain that lasts for months, or even years, after the rash and blisters have cleared up.

Restless legs syndrome (RLS): an uncontrollable urge to move your legs around, often at night. This is usually due to leg discomfort. It may occur most often when you are sitting, laying down, or during bedtime. It can be disruptful to sleep and travel. It is thought RLS may occur due to an imbalance of the chemical dopamine in the brain.

Gabapentin has also been used off-label for the treatment of other types of neuropathic (nerve) pain like peripheral diabetic neuropathy, fibromyalgia and trigeminal neuralgia. “Off-label” uses of gabapentin are uses that have not been approved by the FDA and are not found in the package insert, but may have been accepted for use by healthcare providers based on clinical use.

How does gabapentin come?

There are several brand names of gabapentin including Gralise, Horizant, and Neurontin. Use only the brand and form of gabapentin your doctor has prescribed.

Gralise (gabapentin) is indicated for the management of postherpetic neuralgia only. It is not used for epilepsy. Gralise comes as a 300 and 600 milligram (mg) extended-release (ER) tablet and in a 30-day starter pack of 78 tablets. A generic option is not yet available.

Horizant (gabapentin enacarbil) is used in adults to treat either nerve pain due to postherpetic neuralgia (PHN) or restless legs syndrome (RLS). Horizont is also an extended-release 300 mg or 600 mg tablet and is not interchangeable with other gabapentin products. A generic option is not yet available.

Neurontin (gabapentin) is an immediate-release form used to treat seizures in adults and children who are at least 3 years old, in addition to nerve pain due to shingles. It comes as 100, 300, or 400 mg oral capsules; 600 mg and 800 mg oral tablets, and as a 250 mg per 5 mL oral solution. It is also available as a generic option.

Some brands are only used for certain conditions, and these products may not be interchangeable. Check your medicine each time you get a refill to make sure you have received the correct form.

Some of these medicines may be expensive. Ask your healthcare provider if you are able to use a generic form of gabapentin for your condition (this may not always be possible). Generic options could save you hundreds of dollars each month, or may be less expensive than your insurance copay.

Also, check with the manufacturer who may offer copay cards or patient assistance programs to lessen your overall costs, if you qualify. Be sure to check for online coupons, too, that can save you money on both generics and brands.

To learn more about gabapentin, join the Drugs.com gabapentin Support Group and Q&A Section where you can ask questions, share experiences and keep up with the latest news.

This is not all the information you need to know about gabapentin for safe and effective use and does not take the place of talking to your doctor about your treatment. Review the full gabapentin information here, and discuss this information and any questions you have with your doctor or other health care provider.

Does gabapentin help nerve pain?

Gabapentin is approved to treat the type of nerve pain (neuralgia) that results from nerve damage. Gabapentin is used to treat neuralgia caused by a herpes zoster viral infection, also known as shingles.

This pain is called post-herpetic neuralgia (PHN), and it can be severe and chronic. Gabapentin is also used to treat pain from diabetic neuropathy, which happens when nerves in the feet damaged by diabetes cause chronic burning pain.

The exact way that gabapentin works to relieve pain is not known. It may change the way the body senses and reacts to pain. Gabapentin is used to manage long-term (chronic) pain, not to be taken for pain as needed. Chronic pain can interfere with sleep and work, and lead to depression.

Studies show that pain relief may start within one week and reach a maximum effect in about 4 weeks. It can take this long because gabapentin is usually started at a low dose and gradually increased over time until it works.

For treating neuralgia, gabapentin is often started at 300 mg per day and gradually raised by 300 mg per day. One 2017 review of 37 studies found that pain relief usually occurs at a dose of 1,200 mg or more.

The same review compared gabapentin to an inactive medicine (placebo) in almost 6,000 adults with chronic pain from PHN or diabetic neuropathy. Study participants were given either gabapentin or a placebo for 4 to at least 12 weeks. The results showed that 30-40% of people taking gabapentin were able to reduce their pain by half or more, compared to 10-20% of people taking the placebo.

Although some people may get significant relief, others may have side effects without relief of pain. More than half of people taking gabapentin did not get significant relief and had side effects from the drug.

According to the review, about 60% of people taking gabapentin had side effects, including:

      • Dizziness
      • Sleepiness
      • Water retention (edema)
      • Clumsiness while walking (ataxia)

It does not typically make pain worse: In trials comparing gabapentin side effects to placebo side effects, only 1% of people reported increased pain, and this was the same for gabapentin and placebo.

Once you find the dose that relieves neuralgia for you, it is important not to stop taking it suddenly. Stopping suddenly can lead to withdrawal symptoms such as:

      • Anxiety
      • Insomnia
      • Nausea
      • Pain
      • Sweating

What’s the difference between Lyrica and Gabapentin ?

Both Lyrica and gabapentin are used as anti-epileptic medications and to treat nerve pain.

Lyrica was originally FDA approved as an anti-epileptic drug, also called an anticonvulsant. It works by slowing down impulses in the brain that cause seizures. Pregabalin also affects chemicals in the brain that send pain signals across the nervous system.

Lyrica is used to treat pain caused by fibromyalgia, or nerve pain in people with diabetes (diabetic neuropathy), herpes zoster (post-herpetic neuralgia), or spinal cord injury.

Gabapentin (Neurontin, Gralise, Horizant) is a medicine used to treat partial seizures, nerve pain from shingles and restless leg syndrome. It works on the chemical messengers in your brain and nerves.  Gabapentin is from a group of medicines called anticonvulsants.

Different brands of gabapentin are not interchangeable and they are FDA approved for different conditions. Use only the brand and form of gabapentin your doctor has prescribed. Check your medicine each time you get a refill to make sure you receive the correct form.

Neurontin (gabapentin) is used to treat pain you may have from shingles (postherpetic nerve pain). It is also used with other seizure medicines for partial onset seizures in patients 3 years and older.

Gralise (gabapentin) is only used for pain after having shingles (postherpetic nerve pain). It should not be used for any other medical condition.

Horizant (gabapentin enacarbil) is an extended release tablet used to treat restless legs syndrome and for the pain from having shingles (postherpetic nerve pain).

Generic brands of gabapentin capsules, USP are used for postherpetic nerve pain and for add on therapy for partial onset seizures in patients 3 years and older

But there are several differences between them. The main differences between Lyrica and gabapentin are:

  • Lyrica is a brand name for pregabalin. Gabapentin is the generic name for gabapentin. Gabapentin is not the same as pregabalin, even though they both belong to the same class of medicine, called gabapentinoids, and work similarly
  • Lyrica and Lyrica CR are the only brands of pregabalin. Brand names for gabapentin include Gralise, Horizant, and Neurontin
  • Lyrica and gabapentin are not interchangeable (you cannot switch between them without your doctor’s advice). Even some brands of gabapentin are not interchangeable, for example, gabapentin enacarbil (brand name Horizant) is not interchangeable with Gralise
  • Lyrica may also be used to treat neuropathic (nerve) pain associated with diabetic peripheral neuropathy or postherpetic neuralgia, spinal cord injury, and fibromyalgia. Gabapentin may also be used to treat nerve pain caused by shingles (herpes zoster) and gabapentin enacarbil, brand name Horizant, is also approved for restless legs syndrome (RLS). Gabapentin may also be used for off-label conditions as well
  • Lyrica is more likely than gabapentin to cause side effects such as dry mouth, constipation, swelling (edema), breast enlargement, or weight gain
  • Gabapentin is more likely than Lyrica to cause side effects such as difficulty speaking, fever, an increased risk of viral infections, unusual eye movements, or jerky movements
  • Lyrica is absorbed faster and starts working more quickly than gabapentin. Lyrica reaches its peak concentrations within an hour of being taken, whereas it takes 3 to 4 hours for gabapentin to reach its peak concentration
  • There is some evidence that Lyrica may have a higher addiction potential than gabapentin due to its faster absorption and onset of action
  • Although both drugs have similar interactions, gabapentin may also interact with NSAIDs, such as ibuprofen, naproxen, and diclofenac.

Because Lyrica and gabapentin belong to the same class of medicine (gabapentinoids), they have many similarities, for example:

  • A shared mechanism of action (the way the medicines work), although experts are not exactly sure what the mechanism of action is, they suggest it is through binding to certain pathways in the nervous system. Even though both are structurally like gamma-aminobutyric acid (GABA), they do not bind to GABA or benzodiazepine receptors
  • Both Lyrica and gabapentin have been associated with misuse and in some countries they are classified as controlled substances. Lyrica is classified as a schedule 5 controlled substance in the United States. Gabapentin is not classified as a controlled substance at a Federal level, however some states in the U.S. have classified gabapentin as a controlled substance at a state level. The states that have classified gabapentin as a controlled substance are Kentucky, Virginia, West Virginia, Michigan, and Tennessee. States that include gabapentin in their prescription drug monitoring programs include Minnesota, Ohio, Illinois, Massachusetts, and Wyoming.
  • Some side effects, such as dizziness, drowsiness, loss of balance or coordination, problems with memory or concentration, tremors, and vision problems (blurred vision or double vision) have been reported with both medicines
  • Both Lyrica and gabapentin have been associated with withdrawal syndromes on discontinuation.