Category: Gabapentin

Gabapentin Interactions with other medications and substances

Gabapentin can interact with other prescription and over-the-counter medications, vitamins, and herbal supplements.

People should be sure to give a doctor a full list of their current medications and supplements before taking gabapentin.

The results of another 2017 review suggest that the following are some of the main substances that interact with the drug:

    • caffeine, which is present in tea, coffee, and cola
    • ethacrynic acid, which is a diuretic
    • losartan, which is a medication for high blood pressure
    • magnesium oxide, which is a mineral supplement and antacid
    • mefloquine, which is an antimalarial drug
    • morphine, which is an opioid pain medication
    • phenytoin, which is an anti-seizure medication

If gabapentin causes sleepiness, a person should speak with a doctor before taking other medications that can also cause drowsiness, including:

    • antianxiety medications
    • antidepressants
    • antihistamines
    • cold and flu medications
    • muscle relaxers
    • narcotics, which are pain medications
    • sleeping pills

Presence of other health conditions

To ensure that gabapentin is safe to take, a person should tell a doctor if they also currently have or have ever had:

    • diabetes
    • dialysis treatment
    • drug or alcohol misuse issues
    • heart disease
    • kidney disease
    • liver disease
    • seizures (if taking gabapentin for conditions unrelated to seizures)

What is the maximum daily dosage of Gabapentin?

I’m taking 800mg three times a day for anxiety. It works great. The max recommended dose is 3600mg daily, but I’ve read where some people take up to 4800mg a day. I guess it depends on the person and how they metabolize it.

Although the FDA says 3600mg/day in most places, they have a more extensive doc about gabapentin/neurontin usage and bioavailability. First, your body can only process a certain amount taken and the rest is excreted, so large doses over their bioavailablity chart don’t give larger effects.

Lyrica and other meds have different bioavailability, so use smaller dosages. Since your kidneys do much of the work with gaba/neurontin, you want to make sure you do not have any kidney problems.

A person may need lower doses or not use it due to that. Second, calcium channel meds like gabapentin are nonlinear, so side effects and benefits vary from person to person.

What works or doesn’t work for one, may be the opposite for another. That is why dosage benefits and side effects vary so much from person to person. Even a small dose might make you sleep, but not to another person.

I have heard from some people their doc may prescribe smaller doses during the day and a larger dose at the time of day more problems appear such as at night.

Gaba/neurontin has a short half life so needs doses spread out during the day. One challenging thing is that people that are on gaba are also on other meds too, so there is going to be confusion about what caused what and if there are interactions.

After a couple years, I was only on gaba. For me on maximum dose, I did sleep more, plus several other side effects. It all comes down to finding the most benefit with the least negatives including cost or as docs say, benefits outweigh the risks. Suggest reading more of this forum for a patient viewpoint.

Does Gabapentin cause constipation?

Gabapentin may cause constipation, but it is not a common side effect. In clinical trials of adults taking gabapentin for nerve pain, only about 4% of people reported constipation.

Who may not be able to take gabapentin

Gabapentin is not suitable for some people.

To make sure it’s safe for you, tell your doctor if you:

    • have ever had an allergic reaction to gabapentin or any other medicine
    • have ever misused or been addicted to a medicine
    • are trying to get pregnant or are already pregnant
    • are on a controlled sodium or potassium diet, or your kidneys do not work well (gabapentin liquid contains sodium and potassium, so speak to your doctor before taking it)

Some people in these trials took an inactive medicine (placebo). About 2% of people taking a placebo also reported constipation, so the actual percentage of people with constipation while taking gabapentin is probably less than 4%.

In clinical trials of people aged 12 and over taking gabapentin for seizure disorder, about 2% reported constipation as a side effect. Out of people taking a placebo, 1% also reported constipation.

In the clinical trials of gabapentin to treat nerve pain in adults, the most common side effects were:

  • Dizziness
  • Sleepiness
  • Swelling in the hands or feet (peripheral edema)

In clinical trials of people older than 12 taking gabapentin to treat a seizure disorder, the most common side effects were sleepiness and clumsiness (ataxia).

Thoughts of death or suicide is another rare but important side effect of gabapentin, occurring in about 1 in 500 people. These thoughts can happen within one week of starting gabapentin. Call your doctor right away if you have any unusual changes in mood or behavior, or any of these symptoms:

  • Thoughts about suicide or dying
  • Suicide attempt
  • Depression, new or worsening
  • Anxiety, new or worsening
  • Panic attacks

In 2019, the U.S. Food and Drug Administration (FDA) added another important warning about gabapentin: When this drug is taken with opioid pain medication or used by a person with chronic lung disease like chronic obstructive pulmonary disease (COPD), it may cause severe and possibly fatal difficulty breathing (respiratory depression). Before starting gabapentin, let your doctor know if you are taking any opioid drug, or if you have been diagnosed with a lung disease.

Even if you have side effects from gabapentin, it is important not to stop taking it suddenly on your own. This medication must be reduced over time (tapered) by your doctor. Stopping suddenly can lead to 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.

Does gabapentin help you sleep?

Gabapentin is a prescription medication that may help you sleep. That may be why it has been prescribed for people with insomnia, even though it is not approved for that use.

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

Key facts

  • You’ll usually take gabapentin 3 times a day. You can take it with or without food.
  • Most people who take gabapentin do not get any side effects. But some people may feel sleepy, tired and dizzy. Common side effects are usually mild and go away by themselves.
  • It takes at least a few weeks for gabapentin to work.
  • Most people do not have to stay on the same brand of gabapentin as there’s very little difference between brands.
  • Some people can become addicted to gabapentin after taking it for a long time. When stopping gabapentin you’ll need to reduce your dose gradually to avoid withdrawal symptoms.
  • If you have epilepsy, you are entitled to free prescriptions for all the medicines you take, not just your epilepsy ones. You can get an application form from your doctor’s surgery.

However, gabapentin enacarbil (Horizant) has been approved by the Food and Drug Administration (FDA) to treat a sleep disorder called restless legs syndrome (RLS).

  • One of the most common side effects of gabapentin is drowsiness.
  • In people taking gabapentin for its approved conditions (certain epileptic seizures and postherpetic neuralgia), 19% of patients older than 12 years of age with epilepsy and 21% of patients with postherpetic neuralgia reported drowsiness as a side effect.

Gabapentin and sleep

Most studies show that gabapentin improves slow wave sleep (“deep sleep”) and total sleep time.

  • Two small studies showed that gabapentin may help people with primary insomnia and occasional sleep disturbance improve total sleep time and wakefulness in the morning.
  • In other studies, it appears that gabapentin may improve sleep in people with other medical conditions that make it more difficult to sleep, such as alcohol dependence, hot flashes and bipolar disorder.

In a large review of 26 studies on gabapentin and sleep in patients with other medical conditions, the average dose taken daily was about 1,800 mg. Although positive sleep outcomes were reported, the researchers noted that gabapentin was not tolerated as well as placebo and some patients stopped taking it. Misuse and abuse of the drug has also been reported.

It takes about 2 to 3 hours for immediate-release gabapentin to reach its fullest effect, and it’s typically taken 3 times per day.

RLS treatment

Gabapentin may also be used to treat RLS, a disorder that makes it hard to fall asleep or stay asleep. RLS causes an uncontrollable and uncomfortable urge to move your legs, which is worse at night.

The FDA has approved gabapentin enacarbil (Horizant) — a long-acting gabapentin — as a treatment for RLS.

Side effects of gabapentin

The most common side effects with gabapentin include:

  • Clumsiness
  • Viral infection
  • Drowsiness
  • 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
  • Serious reactions can include:
  • Difficulty breathing
  • Allergic reactions with swelling of the throat or face

Is gabapentin a narcotic/controlled substance?

The anti-seizure medication gabapentin is not currently considered a narcotic or controlled substance by the federal government, but certain states have enacted legislation so that the medication is treated as one or monitored by the state’s prescription drug monitoring program.

The use of a controlled substance is regulated by the federal government to prevent abuse or misuse. Prescription drug monitoring programs track prescriptions of certain medications to flag individuals who may be misusing them and at risk of an overdose.

In addition to preventing seizures in individuals with epilepsy, gabapentin may be prescribed to treat nerve or neuropathic pain caused by herpes virus or shingles in adults.

Gabapentin may be considered as an alternative to opioids, which can be highly addictive and result in overdoses and death. Often prescribed to treat pain, opioids are a controlled substance. Gabapentin is known as an opioid potentiate because it can increase the high felt with opioids such as fentanyl, oxycodone, hydrocodone, codeine, morphine and even the street drug heroin.

As a result, gabapentin has potential for misuse or abuse. The combination of opioids and gabapentin may increase the risk of dying from an overdose likely due to depressed breathing. Individuals with chronic obstructive pulmonary disease (COPD) and the elderly are at greatest risk of dying from this combination.