How Long Does Gabapentin Stay in Your System?

Gabapentin is a prescription medication used to treat some seizure disorders and neuropathic pain under the brand name Neurontin or Gralise. There are many other off-label uses for gabapentin, or uses that are not approved by the FDA:

  • Alcohol withdrawal
  • Cough
  • Fibromyalgia
  • Hiccups
  • Pruritus
  • Restless legs syndrome
  • Social anxiety disorder

Typically, gabapentin stays in the body for up to 45 hours, but it may be detected in drug tests for different lengths of time.

Article at a Glance

  • Most pre-employment drug tests do not normally test for gabapentin.
  • While gabapentin is not a controlled medication at the federal level, some states are beginning to regulate it as a narcotic because of its abuse potential.
  • Urine drug tests can detect gabapentin for 1–2 days, but these tests must be specially ordered.
Gabapentin pills spilled on a blue countertop

How Long Does it Take for Gabapentin to Work?

Gabapentin is available as an immediate-release or extended-release tablet. The time it takes for either formulation to work depends on several factors such as age, kidney function and other medications. Because gabapentin can be used for a variety of indications, the time it takes for effects to kick in can vary.

In general, sleep problems due to nerve pain can improve in a week, but it may take up to two weeks to notice relief from the pain itself. Seizure reduction is often noticeable within a few weeks of starting gabapentin. Symptom relief from restless legs syndrome or postherpetic neuralgia, the nerve pain after shingles, may take several days or weeks to develop.

How Long Does Gabapentin Last?

While the exact mechanism for how gabapentin works is unknown, it is known that gabapentin slows signals in the brain. Gabapentin readily crosses the blood-brain barrier, where its effect takes place. Doses may vary, ranging from 300 to 3000 mg per day and is tolerated to effect or added on to another medication, depending on the indication.

Conventional, or immediate-release, gabapentin, is usually taken three times daily since its half-life is approximately 5–7 hours. While gabapentin is detectable for three to five times that long, the concentration in the blood would be too low to prevent seizures or pain.

How Long Do Gabapentin Side Effects Last?

Most common side effects of gabapentin go away within the first month of taking the drug. Common side effects include:

  • Anxiety
  • Blurred Vision
  • Constipation or diarrhea
  • Dizziness
  • Drowsiness
  • Dry Mouth
  • Headache
  • Heartburn
  • Increased Appetite
  • Memory Problems
  • Nausea
  • Tiredness or Weakness
  • Unsteadiness
  • Vomiting

Side effects typically go away within days of stopping gabapentin because of its relatively short half-life.

Gabapentin Half-Life

Immediate-release gabapentin has a half-life of about 5–7 hours. In addition to patient-specific factors such as age, kidney function and presence of other medications or substances, this number may increase as the dose increases. For this reason, immediate-release gabapentin is often taken three times daily, or up to twice daily for patients with impaired kidney function.

The extended-release formulation of gabapentin, under the brand name Horizant, has the same gabapentin half-life but is released more slowly throughout the day than the immediate-release formulation. For this reason, the extended release formulation is only taken once daily.

Does Gabapentin Show Up on a Drug Test?

Pre-employment and random drug tests do not typically test for gabapentin. However, some addiction centers may order a special test for gabapentin if there is suspicion this medication is being misused.

How Long Does Gabapentin Stay in Urine?

Gabapentin can be detected in urine for 1–2 days.

How Long Does Gabapentin Stay in Your Blood?

Gabapentin is detected in blood several hours after use, and can be detected for up to two days depending on how much was used.

How Long Does Gabapentin Stay in Your Hair?

While hair follicle tests usually measure within the previous 90 days, gabapentin is not typically included unless it is specifically requested.

Factors Affecting How Long Gabapentin Stays in Your System

While gabapentin is not a federally controlled substance, some U.S. states have started regulating it as a result of increasing misuse. One study estimated the prevalence of gabapentin abuse and misuse to be 40–65% among people with prescriptions and 15–22% in populations abusing opioids, compared with 1% in the general population.

Gabapentin can stay in the system for about 45 hours in most people. Some factors that may impact metabolism include:

  • Amount used: Gabapentin accumulates in the body when taken in high amounts. Taking large doses may prolong the time it stays in the body.
  • Frequency of use: Gabapentin will stay in the body longer in people who use it frequently as the concentration in the blood is increased.
  • Age: In general, kidney function declines with age. Therefore, older adults metabolize gabapentin more slowly because the kidneys are responsible for metabolizing gabapentin.
  • Overall health: The length of time gabapentin stays in the body is directly proportional to kidney function. The half-life of gabapentin in people with kidney failure can be up to 132 hours, meaning it can stay in the body for 28 days without dialysis.

How Is Gabapentin Metabolized?

When a dose of gabapentin is taken, it is absorbed in the small intestine and then enters the bloodstream. From there, it crosses the blood-brain barrier where it takes effect via unknown mechanisms in the brain.

Gabapentin is eliminated completely by the kidneys, rather than by the liver like some other medications. The kidneys filter gabapentin from the blood and eliminate it from the body through urine. For this reason, people with impaired kidney function metabolize gabapentin more slowly or accumulate the medication if too much is taken. For example, the reported half-life of one dose in a patient with end-stage kidney failure who is not producing urine would be 132 hours.

How Long Can You Stay on Gabapentin?

While there is a risk of becoming tolerant to gabapentin, where more of the medication is needed to produce the same effect, gabapentin may be safe for long-term use in certain cases. Your healthcare provider will routinely evaluate for side effects and to determine if the medication is still effective. If gabapentin is determined to be safe and effective, use can usually be continued. Sedation, dizziness and forgetfulness are some common side effects that may be present long-term or with higher doses.

Gabapentin Withdrawal

Withdrawal from gabapentin typically begins 12 hours–7 days after the last dose. Abruptly stopping gabapentin can result in seizures or other more mild withdrawal symptoms such as anxiety, insomnia, nausea or pain.

To avoid this, it is important to discuss stopping this medication with your healthcare provider. The safest way to ease symptoms of withdrawal is to slowly taper your dose under medical supervision. Your provider will consider the dose you’re currently taking to determine how quickly or slowly you can safely taper use.

Gabapentin Abuse

Even though gabapentin is not a controlled medication under the Controlled Substances Act, some states have started regulating it as a result of increasing misuse. If you or someone you love is taking gabapentin more often or differently than prescribed, this may be a sign of misuse.

If you or someone you care about is struggling with gabapentin addiction, The Recovery Village Ridgefield can help. The Recovery Village Ridgefield aims to help curb addiction throughout Washington and Oregon and provides people with a safe environment that promotes lifelong recovery.

We offer a full continuum of treatments that includes medical detox, inpatient treatment, outpatient care and partial hospitalization programs (PHPs). Now, we also offer online counseling in order to make ongoing treatment more accessible. Contact us today to learn more about gabapentin addiction programs that can work well for your unique situation.

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Medical Disclaimer: The Recovery Village aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.