Akathisia Induced by Gabapentin Withdrawal

Gabapentin-Associated Movement Disorders: A Literature Review

BACKGROUND

Gabapentin (GBP)-induced movement disorders (MDs) are under-recognized adverse drug reactions. They are commonly not discussed with patients, and their sudden occurrence can lead to misdiagnosis. This literature review aims to evaluate the clinical-epidemiological profile, pathological mechanisms, and management of GBP-associated MD.

METHODS

Two reviewers identified and assessed relevant reports in six databases without language restriction between 1990 and 2023.

RESULTS

A total of 99 reports of 204 individuals who developed a MD associated with GBP were identified. The MDs encountered were 135 myoclonus, 22 dyskinesias, 7 dystonia, 3 akathisia, 3 stutterings, 1 myokymia, and 1 parkinsonism. The mean and median ages were 54.54 (SD: 17.79) and 57 years (age range: 10-89), respectively. Subjects were predominantly male (53.57%). The mean and median doses of GBP when the MD occurred were 1324.66 (SD: 1117.66) and 1033 mg/daily (GBP dose range: 100-9600), respectively. The mean time from GBP-onset to GBP-associated MD was 4.58 weeks (SD: 8.08). The mean recovery time after MD treatment was 4.17 days (SD: 4.87). The MD management involved GBP discontinuation. A total of 82.5% of the individuals had a full recovery in the follow-up period.

CONCLUSIONS

Myoclonus (GRADE A) and dyskinesia (GRADE C) were the most common movement disorders associated with GBP.

Antiseizure Drugs and Movement Disorders

The relationship between antiseizure drugs and movement disorders is complex and not adequately reviewed so far. Antiseizure drugs as a treatment for tremor and other entities such as myoclonus and restless leg syndrome is the most common scenario, although the scientific evidence supporting their use is variable. However, antiseizure drugs also represent a potential cause of iatrogenic movement disorders, with parkinsonism and tremor the most common disorders. Many other antiseizure drug-induced movement disorders are possible and not always correctly identified. This review was conducted by searching for all the possible combinations between 15 movement disorders (excluding ataxia) and 24 antiseizure drugs. The main objective was to describe the movement disorders treated and worsened or induced by antiseizure drugs. We also summarized the proposed mechanisms and risk factors involved in the complex interaction between antiseizure drugs and movement disorders. Antiseizure drugs mainly used to treat movement disorders are clonazepam, gabapentin, lacosamide, levetiracetam, oxcarbazepine, perampanel, phenobarbital, pregabalin, primidone, topiramate, and zonisamide. Antiseizure drugs that worsen or induce movement disorders are cenobamate, ethosuximide, felbamate, lamotrigine, phenytoin, tiagabine, and vigabatrin. Antiseizure drugs with a variable effect on movement disorders are carbamazepine and valproate while no effect on movement disorders has been reported for brivaracetam, eslicarbazepine, lacosamide, and stiripentol. Although little information is available on the adverse effects or benefits on movement disorders of newer antiseizure drugs (such as brivaracetam, cenobamate, eslicarbazepine, lacosamide, and rufinamide), the evidence collected in this review should guide the choice of antiseizure drugs in patients with concomitant epilepsy and movement disorders. Finally, these notions can lead to a better understanding of the mechanisms involved in the pathophysiology and treatments of movement disorders.

Extracorporeal Treatment for Gabapentin and Pregabalin Poisoning: Systematic Review and Recommendations From the EXTRIP Workgroup

Toxicity from gabapentin and pregabalin overdose is commonly encountered. Treatment is supportive, and the use of extracorporeal treatments (ECTRs) is controversial. The EXTRIP workgroup conducted systematic reviews of the literature and summarized findings following published methods. Thirty-three articles (30 patient reports and 3 pharmacokinetic studies) met the inclusion criteria. High gabapentinoid extracorporeal clearance (>150mL/min) and short elimination half-life (<5 hours) were reported with hemodialysis. The workgroup assessed gabapentin and pregabalin as "dialyzable" for patients with decreased kidney function (quality of the evidence grade as A and B, respectively). Limited clinical data were available (24 patients with gabapentin toxicity and 7 with pregabalin toxicity received ECTR). Severe toxicity, mortality, and sequelae were rare in cases receiving ECTR and in historical controls receiving standard care alone. No clear clinical benefit from ECTR could be identified although major knowledge gaps were acknowledged, as well as costs and harms of ECTR. The EXTRIP workgroup suggests against performing ECTR in addition to standard care rather than standard care alone (weak recommendation, very low quality of evidence) for gabapentinoid poisoning in patients with normal kidney function. If decreased kidney function and coma requiring mechanical ventilation are present, the workgroup suggests performing ECTR in addition to standard care (weak recommendation, very low quality of evidence).

Complex encephalopathy arising from the combination of opioids and gabapentin

The interactions between opioids and gabapentin are more clinically relevant than ever. Prescriptions dispensed for gabapentin increased from 39 million in 2012 to 64 million in 2018 in the USA and are ever increasing. Authors present a challenging case of these interactions. A 58-year-old man presented to the emergency department with acute respiratory failure and altered mental status. He was on high dose opioids and gabapentin as prescription medications. Despite full intensive care support and resolution of his respiratory failure with non-invasive positive pressure ventilation, the patient did not regain consciousness. After ruling out other causes, the diagnosis of gabapentin withdrawal was considered. Gabapentin was administered by a nasogastric tube that quickly resulted in a reversal of his symptoms. We concluded that severe gabapentin withdrawal should be considered in patients on higher doses of gabapentin when it is stopped abruptly. In such patients, gabapentin should be replaced. As most patients are unable to swallow in this situation and intravenous formulation is not available, nasogastric tube can be used for replacement.

Commentary on "A Call for Caution in Prescribing Gabapentin to Individuals with Concurrent Polysubstance Abuse: A Case Report"

Gabapentin is an anticonvulsant medication with an indication from the US Food and Drug Administration for use in partial onset seizures and postherpetic neuralgia in the United States. Currently, gabapentin is only classified as a controlled substance subject to stricter prescribing and distributing regulations in certain states, as opposed to pregabalin, an anticonvulsant with a similar mechanism of action which is a considered a Schedule V medication under federal law. Gabapentin shares a structural similarity to pregabalin, and several case reports have suggested that gabapentin has a similar propensity for abuse. The mechanisms of the gabapentin reward pathway, addiction, and withdrawal, however, are not well known. This case report describes a patient with long-term polysubstance abuse and new onset gabapentin dependence and demonstrates the need for increased surveillance of gabapentin prescribing.

A Call for Caution in Prescribing Gabapentin to Individuals With Concurrent Polysubstance Abuse: A Case Report

Gabapentin is an anticonvulsant medication with an indication from the US Food and Drug Administration for use in partial onset seizures and postherpetic neuralgia in the United States. Currently, gabapentin is only classified as a controlled substance subject to stricter prescribing and distributing regulations in certain states, as opposed to pregabalin, an anticonvulsant with a similar mechanism of action which is a considered a Schedule V medication under federal law. Gabapentin shares a structural similarity to pregabalin, and several case reports have suggested that gabapentin has a similar propensity for abuse. The mechanisms of the gabapentin reward pathway, addiction, and withdrawal, however, are not well known. This case report describes a patient with long-term polysubstance abuse and new onset gabapentin dependence and demonstrates the need for increased surveillance of gabapentin prescribing.

Complex encephalopathy arising from the combination of opioids and gabapentin

The interactions between opioids and gabapentin are more clinically relevant than ever. Prescriptions dispensed for gabapentin increased from 39 million in 2012 to 64 million in 2018 in the USA and are ever increasing. Authors present a challenging case of these interactions. A 58-year-old man presented to the emergency department with acute respiratory failure and altered mental status. He was on high dose opioids and gabapentin as prescription medications. Despite full intensive care support and resolution of his respiratory failure with non-invasive positive pressure ventilation, the patient did not regained consciousness. After ruling out other causes, the diagnosis of gabapentin withdrawal was considered. Gabapentin was administered by a nasogastric tube that quickly resulted in a reversal of his symptoms. We concluded that severe gabapentin withdrawal should be considered in patients on higher doses of gabapentin when it is stopped abruptly. In such patients, gabapentin should be replaced. As most patients are unable to swallow in this situation and intravenous formulation is not available, nasogastric tube can be used for replacement.

How addictive are gabapentin and pregabalin? A systematic review

In the last ten years, gabapentin and pregabalin have been becoming dispensed broadly and sold on black markets, thereby, exposing millions to potential side-effects. Meanwhile, several pharmacovigilance-databases have warned for potential abuse liabilities and overdose fatalities in association with both gabapentinoids. To evaluate their addiction risk in more detail, we conducted a systematic review on PubMed/Scopus and included 106 studies. We did not find convincing evidence of a vigorous addictive power of gabapentinoids which is primarily suggested from their limited rewarding properties, marginal notes on relapses, and the very few cases with gabapentinoid-related behavioral dependence symptoms (ICD-10) in patients without a prior abuse history (N=4). In support, there was no publication about people who sought treatment for the use of gabapentinoids. Pregabalin appeared to be somewhat more addictive than gabapentin regarding the magnitude of behavioral dependence symptoms, transitions from prescription to self-administration, and the durability of the self-administrations. The principal population at risk for addiction of gabapentinoids consists of patients with other current or past substance use disorders (SUD), mostly opioid and multi-drug users, who preferred pregabalin. Pure overdoses of gabapentinoids appeared to be relative safe but can become lethal (pregabalin > gabapentin) in mixture with other psychoactive drugs, especially opioids again and sedatives. Based upon these results, we compared the addiction risks of gabapentin and pregabalin with those of traditional psychoactive substances and recommend that in patients with a history of SUD, gabapentinoids should be avoided or if indispensable, administered with caution by using a strict therapeutic and prescription monitoring.

Gabapentin: Abuse, Dependence, and Withdrawal

OBJECTIVE

To identify case reports and studies regarding patients who abused, became dependent on, or experienced withdrawal from gabapentin.

DATA SOURCES

A PubMed literature search (1993 to October 2015) was performed using the search terms gabapentin, withdrawal, dependence, and addiction. Additional references were identified from a review of literature citations.

STUDY SELECTION

All English-language case reports and studies were evaluated.

DATA SYNTHESIS

A total of 18 case reports or case series were identified regarding addiction to or withdrawal from gabapentin. All the cases of addiction were in patients who had a previous history of alcohol, cocaine, or opioid abuse. On average, the patients were taking more than 3000 mg/d (600-8000 mg/d). Two surveys reported that the misuse of gabapentin was 1.1% in the general population and 22% in drug abuse treatment centers. Withdrawal, when reported, occurred within 12 hours to 7 days of discontinuation of the medication.

CONCLUSION

There have been numerous documented cases of gabapentin abuse, dependence, and withdrawal. Even though gabapentin is sometimes considered as a treatment option for alcohol and substance abuse, it is important to monitor for drug-seeking behaviors. A history of alcohol or substance abuse appears to be an important part of a patient's medical history when evaluating their risk for addiction and dependence behaviors. Health care providers need to be aware of this risk in their patients and monitor their patients for signs of abuse and dependence along with withdrawal symptoms.

Gabapentin pharmacotherapy for antipsychotic-induced akathisia: single-patient experiment and case report

This clinical study reports upon the efficacy of gabapentin (Neurontin) for treating severe akathisia (3 on the Barnes Akathisia Rating Scale) in two patients receiving quetiapine (Seroquel), one of whom also received olanzapine (Zyprexa) for a short period. The first patient participated in an open-label experiment in which the bedtime dose of gabapentin was discontinued three times at intervals 1 week apart, resulting in severe akathisia which was quickly terminated by taking his usual 1200 mg gabapentin dose. This patient was also taking high doses of two benzodiazepines and a beta blocker, without therapeutic effect upon his akathisia; only gabapentin was efficacious. The second case is a report of a woman taking a high dose of quetiapine for anxiety who experienced severe akathisia which was relieved by taking 1200 mg of gabapentin. Possible mechanisms of action of gabapentin are discussed. Particular attention is drawn to the difference between neuroleptic-induced akathisia and the neurological condition of restless legs syndrome.

Pharmacogenetic workup of perioperative serotonin syndrome

Serotonin syndrome is gaining attention in perioperative and chronic pain settings due to the growing prevalence of multimodal therapies that increase serotonin levels and thereby heighten patient risk. A patient's genetic make-up may further increase the risk of serotonin syndrome. A case of serotonin syndrome on emergence after general anesthesia is presented. A subsequent cytochrome P4502D6 genetic test result suggested a potential alteration in metabolism. For this patient, who was taking combination antidepressant medications and receiving common perioperative medicines, additive pharmacodynamic effects converged with a pharmacogenetic predisposition, resulting in serotonin syndrome.

Pregnancy outcomes following gabapentin use: results of a prospective comparative cohort study

OBJECTIVES

Our objectives were to 1) determine whether first-trimester use of gabapentin is associated with an increased risk for major malformations; 2) examine rates of spontaneous abortions, therapeutic abortions, stillbirths, mean birth weight and gestational age at delivery; and 3) examine rates of poor neonatal adaptation syndrome following late pregnancy exposure.

METHODS

The study design was prospective. Women were included who initially contacted the services between 5 and 8 weeks with a comparison group of women exposed to nonteratogens, collected in a similar manner.

RESULTS

We have data on 223 pregnancy outcomes exposed to gabapentin and 223 unexposed pregnancies. The rates of major malformations were similar in both groups (p = 0.845). There was a higher rate of preterm births (p = 0.019) and low birth weight <2,500 g (p = 0.033) in the gabapentin group. Among infants who were exposed to gabapentin up until delivery, 23 of 61 (38%) were admitted to either the neonatal intensive care unit or special care nursery for observation and/or treatment, vs 6 of 201 (2.9%) live births in the comparison group (p < 0.001). There were 2 cases of possible poor neonatal adaptation syndrome in neonates exposed to gabapentin close to delivery, compared with none in the comparison group, although it must be noted that these infants were concomitantly exposed to other psychotropic drugs. Among the women who took gabapentin, the major indications were pain (n = 90; 43%) and epilepsy (n = 71; 34%); the remainder were for other indications, mostly psychiatric.

CONCLUSION

Our results suggest that although this sample size is not large enough to make any definitive conclusions, and there was no comparator group treated with other antiepileptic drugs, gabapentin use in pregnancy does not appear to increase the risk for major malformations. This finding and the increased risk for low birth weight and preterm birth require further investigation.

Implications and mechanism of action of gabapentin in neuropathic pain

Gabapentin is an anti-epileptic agent but now it is also recommended as first line agent in neuropathic pain, particularly in diabetic neuropathy and post herpetic neuralgia. α2δ-1, an auxillary subunit of voltage gated calcium channels, has been documented as its main target and its specific binding to this subunit is described to produce different actions responsible for pain attenuation. The binding to α2δ-1 subunits inhibits nerve injury-induced trafficking of α1 pore forming units of calcium channels (particularly N-type) from cytoplasm to plasma membrane (membrane trafficking) of pre-synaptic terminals of dorsal root ganglion (DRG) neurons and dorsal horn neurons. Furthermore, the axoplasmic transport of α2δ-1 subunits from DRG to dorsal horns neurons in the form of anterograde trafficking is also inhibited in response to gabapentin administration. Gabapentin has also been shown to induce modulate other targets including transient receptor potential channels, NMDA receptors, protein kinase C and inflammatory cytokines. It may also act on supra-spinal region to stimulate noradrenaline mediated descending inhibition, which contributes to its anti-hypersensitivity action in neuropathic pain.