Gabapentin Overdose: Dosage, Signs, Risks & Treatment

Gabapentin is not a federally controlled substance, but misuse is becoming more and more popular, leading to the possibility of overdose. Help is available.

Gabapentin is a prescription medication commonly used to prevent seizures or to treat nerve pain and may be effective in treating other conditions like fibromyalgia, Restless Leg Syndrome, or alcohol withdrawal. While gabapentin is not a controlled medication under the Controlled Substances Act, some states have started regulating it due to increased misuse and abuse.

Gabapentin overdose is possible. While it may not be as fatal as other prescription medications, combining a gabapentin overdose with alcohol or opioid use can still be highly dangerous.

What Is Gabapentin?

Gabapentin is a prescription medication most often used to prevent seizures or treat nerve pain. While it is not clear exactly how gabapentin works, it appears to slow signals between the brain and body. In addition to being used for seizures and nerve pain, gabapentin also has many potential off-label — or non-FDA-approved — uses, including:

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

Gabapentin is not a controlled medication under the Controlled Substances Act, but some U.S. states have begun treating it as such due to increasing misuse and abuse.

See Related: Lyrica vs. Gabapentin

Gabapentin Dosage

Gabapentin is often titrated to effect and, as a result, doses can vary from person to person and can change over time. Most commonly prescribed as capsules or tablets, examples of available dosages include:

• 100mg
• 300mg
• 400mg
• 600mg
• 800mg

Gabapentin is also available as a liquid, often used in children to prevent seizures.

Gabapentin Dosage for Nerve Pain

The exact way that gabapentin helps with nerve pain is not known, but it may change the way the body senses and reacts to pain. For neuralgia or nerve pain, gabapentin is often started at 300 mg daily and increased by 300 mg per day until pain relief is achieved. Some studies show doses of 1200 mg or more per day is effective for nerve pain.

Gabapentin Dosage for Anxiety

Used in combination with other medications, gabapentin is sometimes helpful for anxiety. While there is limited information for this use, there are some examples where it has been helpful. In one instance, doses of at least 900 mg per day were shown to be helpful in a patient with Generalized Anxiety Disorder (GAD) whereas severe symptoms of anxiety returned at doses less than 600 mg per day.

Gabapentin Dosage for Seizures

Gabapentin seems to slow signaling between the brain and the body, but its exact mechanism for preventing seizures is not known. Typically, gabapentin is started at 300 mg three times per day for this use and slowly increases. Over the long term, doses totaling up to 2400 mg per day have been well tolerated. For short periods, as much as 3600 mg divided throughout the day has been used.

Gabapentin Dosage for Restless Leg Syndrome

Similar to the way gabapentin may be helpful in preventing seizures by slowing signals between the brain and the body, gabapentin may also be helpful for Restless Leg Syndrome (RLS). For RLS, gabapentin enacarbil 600mg, under the brand name Horizant, is taken each evening and can be slowly increased to effect.

What Happens if You Take Too Much Gabapentin?

Like any medication, gabapentin can cause a variety of unintentional side effects. These can develop or become more pronounced any time the dose is increased or if you start taking gabapentin after stopping for a while. These side effects usually go away after the body adjusts to the medication, but contact your healthcare provider if you experience side effects that are severe or do not go away.

Common side effects of gabapentin:

• Drowsiness
• Tiredness or weakness
• Dizziness
• Headache
• Uncontrollable shaking
• Double or blurred vision
• Anxiety
• Memory problems
• Strange or unusual thoughts
• Unwanted eye movements
• Nausea/vomiting
• Diarrhea
• Dry mouth
• Constipation
• Weight gain
• Swelling of hands, feet, ankles or lower legs

Serious side effects of gabapentin:

• Rash
• Itching
• Swelling of the face, throat, tongue, lips or eyes
• Hoarseness
• Difficulty swallowing or breathing
• Seizures
• Bluish-tinged skin, lips or fingernails
• Confusion
• Extreme sleepiness

Can You Overdose on Gabapentin?

Gabapentin is not a controlled medication under the Controlled Substance Act, but misuse and abuse of this medication is on the rise. From 2012 to 2016 in the United States, gabapentin prescribing increased by 64%. With this increase in prescribing, the number of people misusing and abusing gabapentin also increased.

The short answer is yes, you can overdose on gabapentin. While gabapentin overdose is less likely to be fatal than with some other medications, like opioids, gabapentin is often taken with other medications or alcohol which add more risks.

Gabapentin Lethal Dosage

Some factors can impact how much gabapentin is lethal — one of the most important being whether gabapentin was taken with other medications or alcohol. By itself, gabapentin would need to be taken in very high doses to be lethal. In mice, the lethal dose for 50% of subjects was over 5000 mg/kg.

Gabapentin Overdose Symptoms

Symptoms of gabapentin overdose are severe and should be treated immediately. These include:

• Double vision
• Slurred speech
• Drowsiness
• Diarrhea

If you suspect that you or someone you love may be overdosing on gabapentin, call 911 immediately or contact Poison Control online or at 1-800-222-1222.

Gabapentin Overdose Risk Factors

There are many drug and alcohol combinations that can increase the risk for overdose when taken with gabapentin. Often, these combinations result in respiratory depression, where the brain and body are not getting enough oxygen. As a result, breathing can be slow or shallow and in some cases, even stop.

Gabapentin and Alcohol

Both gabapentin and alcohol are depressants. This means that each decreases the signaling between the body and the brain. When taken together, the effect is even more pronounced than each substance separately, and this combination can lead to overdose. If you take gabapentin and alcohol together, you may feel especially drowsy or dizzy and may be at increased risk for seizures. In 2019, the FDA issued a warning that the risk of respiratory depression is higher with certain risk factors, including if mixed with depressants such as alcohol.

Gabapentin and Opioids

Similar to the risks associated with combining gabapentin with alcohol, gabapentin and opioids can also increase the risk for overdose when taken together. In the same FDA-issued warning in 2019, the FDA also cautions that taking gabapentin with opioids can increase risk of respiratory depression and may lead to overdose.

Other Gabapentin Drug Interactions

Other central nervous system (CNS) depressants can increase the risk for overdose when taken with gabapentin. Similar to alcohol and opioids, anti-anxiety medications, antidepressants and antihistamines can each increase the risk for gabapentin overdose because these types of medicines decrease signals between the brain and body, putting you at risk for respiratory depression.

Gabapentin Abuse

While the overall likelihood of abuse is relatively low for this medication, the rate of gabapentin abuse among patients with known substance use disorders was found to be 15% to 22%. In recent years, the number of gabapentin prescriptions has increased as the number of opioid prescriptions has decreased. It is possible that the potential for gabapentin misuse and abuse had previously been underestimated.

Some people report feelings of euphoria, dissociation, relaxation, sedation, and sometimes psychedelic effects after taking gabapentin. This is noted most often after taking high doses or mixing it with other drugs and alcohol, which is potentially dangerous.

What Happens If I Miss a Dose?

Consult your healthcare provider or pharmacist if you have missed a dose and are not sure if you should skip your dose or take it. Depending on why you take gabapentin, missing doses can lead to seizures or increased pain.

Never “double up” to catch your gabapentin dose up as this can lead to serious side effects or accidental overdose.

Gabapentin Overdose Treatment

If you or someone you know is showing signs of gabapentin overdose or allergic reaction, call 911 immediately. If left untreated, this can be serious or even fatal. The dispatcher will walk you through exactly what you can do until help arrives.

Once emergency medical services arrive, they will provide supportive care and treat symptoms. If another medication, like an opioid, was taken, EMS may administer naloxone to reverse its effects. Other treatments will depend on symptoms that may be present and can include:

• Providing oxygen and maintaining an open airway
• Management and treatment for delirium, agitation, confusion or aggression
• Protect the patient from self-harm

Getting Help for Gabapentin Abuse

If you or someone you love is struggling with gabapentin addiction, contact us today. We are here to help. We will work with you to taper your medication down safely while providing the support you need to live a drug-free life.

At The Recovery Village at Baptist Health, we offer many treatment programs to support you, ranging from inpatient rehabilitation to teletherapy and aftercare planning. Our programs are customized to your needs to provide you with a path to recovery. Contact us today.