Delirium Associated With Baclofen Withdrawal: A Review of Common Presentations and Management Strategies

Case of tizanidine withdrawal showing hallucination, decorticate posture and tremor, with hypersympathetic vital signs

Tizanidine, an α2-adrenergic receptor agonist commonly prescribed as a muscle relaxant, has been associated with limited cases of acute intoxication or withdrawal. Here, we present a case of tizanidine withdrawal in a woman in her 40s who presented with an unusual combination of systemic and neurological symptoms. These included hallucinations, decorticate posture, limb and eyelid tremors, along with hypertension, tachycardia and tachypnoea. The diagnosis of tizanidine withdrawal was established by a comprehensive assessment of the patient's medical history and the systematic exclusion of other potential diseases. Our approach to managing the withdrawal symptoms was to initiate symptomatic treatment with a combination of a beta-blocker and a calcium channel blocker. Remarkably, this intervention successfully resolved both vital signs and neurological manifestations by the following day. In conclusion, tizanidine withdrawal is associated with a distinct and diagnostically significant neurological syndrome characterised by hallucinations, decorticate posture, tremors and hypersympathetic vital signs.

Baclofen in the treatment of alcohol use disorder: tailored doses matter

AIMS

To address the question of tailored baclofen prescribing in alcohol use disorder (AUD) in relation to dose-dependent efficacy and the potential danger of high doses and to provide suggestions for the use of high doses of baclofen in the treatment of AUD. The context is the approvement in France of baclofen in the treatment of AUD without dose limitation, making French physicians, who usually prescribe baclofen in a tailored manner, often use high or very high doses.

METHODS

A narrative review of the results of randomized controlled trials (RCTs) and observational studies that used tailored baclofen prescribing and of the severe adverse effects of baclofen that have been reported in the literature.

RESULTS

The results show that RCTs using tailored doses of baclofen in AUD are not completely demonstrative, though they are encouraging according to certain meta-analyses, while observational studies that used tailored doses constantly show a good effectiveness of baclofen treatment. The results suggest that many severe adverse effects of baclofen could be related to a nonrespect by physicians of prescription rules and appropriate treatment monitoring.

CONCLUSIONS

The use of tailored doses shows that the dose required to suppress cravings is highly variable, low or high, depending on each case. Analysis of the circumstances in which severe adverse effects occur suggest that a careful monitoring of baclofen prescribing might prevent a large majority of severe adverse effects. We propose that the education of the patients and the prescription skills, seriousness, and availability of the prescribing physicians are of major importance in the managing of tailored baclofen treatment of AUD.

Reasons for use and experiences of using phenibut, a mixed methods analysis of online reports

Background: Phenibut is a drug similar in structure to gabapentin and pregabalin. It is available online without prescription, often marketed as a dietary supplement or amino acid derivative. Little is known about phenibut use despite its increased popularity in the United States over the last decade.Objective: To clarify reasons for taking phenibut, circumstances, and effects of use.Methods: Reports of phenibut, gabapentin, and pregabalin use were downloaded from a publicly-available database, Erowid.org. A mixed methods approach utilizing qualitative content analysis was used.Results: Of 229 reports, 211 were from male authors. People usually purchased phenibut online and reportedly used it for recreation, to manage a medical or psychiatric problem (primarily insomnia, anxiety), as a substitute for other drugs (especially benzodiazepines), to manage withdrawal from another substance (including benzodiazepines, opioids), and/or for performance enhancement. While it shared many reported effects with pregabalin and gabapentin such as anxiolysis, increased talkativeness, and impaired motor coordination, reports of gastrointestinal distress and sedation were more commonly attributed to phenibut. Several people reported difficulty in restricting their use and managing withdrawal.Conclusions: Phenibut reports suggest that phenibut may have some benefits for some people. Use also, however, carries risks of adverse effects, a potentially dangerous withdrawal syndrome, and addiction. Not dissimilar to unprescribed gabapentin or pregabalin, self-medication is a common motive for phenibut use. Physicians should continue to ask their patients about use of any non-prescribed medications, dietary supplements, or "amino acid derivatives."Abbreviation: PWUPh: people who use phenibut; PWUG: people who use gabapentin; PWUPr: people who use pregabalin.

The impact of intrathecal baclofen on the ability to walk: A systematic review

OBJECTIVE

Intrathecal baclofen (ITB) is an effective treatment for lower limb spasticity. In ambulatory patients with spasticity, there is a justifiable concern that ITB treatment may compromise ambulatory function by reducing the heightened muscle tone, thereby unmasking underlying muscle weakness. ITB is hence offered with reservation in ambulant patients. In this article, we review the literature surrounding the effect of ITB therapy on ambulatory function in patients with concurrent spasticity and discuss the key findings.

DATA SOURCES

A literature search of ProQuest Medline and EBSCO CINAHL databases was performed.

REVIEW METHOD

Inclusion criteria included (a) studies reporting the effect of ITB in adult ambulatory patients; (b) studies with an intervention of screening test trial via either bolus injections or continuous infusion tests; and (c) studies with an intervention of ITB pump implantation. Seventeen eligible studies were identified and two authors independently assessed the study quality using the risk of bias in nonrandomised studies of interventions tool (ROBINS-I).

RESULTS

Seventeen studies were included, with a total of 534 participants. Most of the patients remain ambulatory after ITB treatment, accompanied by improvements in gait speed and reduction in spasticity.

CONCLUSION

ITB therapy when administered in carefully selected ambulatory patients with spasticity is not associated with loss of ambulatory function.

Transient alteration of consciousness in spinal cord injury secondary to Baclofen use: a case report

INTRODUCTION

Oral baclofen is commonly used for spasticity management, especially with neurogenic bladder in spinal cord injury (SCI). A less common side effect of baclofen is transient alterations of consciousness, which can easily be confused for altered mental status secondary to orthostatic hypotension in SCI.

CASE PRESENTATION

A 43-year-old man with an acute SCI secondary to an aortic dissection was found to have episodes of confusion after titrating oral baclofen from 5 mg three times per day to 10 mg three times per day at an acute rehabilitation facility. Orthostatic hypotension was initially suspected as the cause of transient alterations of consciousness; however, he was never found to be hypotensive during these episodes. His confusion resolved several days after discontinuation of baclofen.

DISCUSSION

Although, confusion and lightheadedness in SCI are commonly caused by orthostatic hypotension, it is important for physicians to be cognizant of baclofen's side effects, which increase in the setting of acute kidney injury (AKI). If an adverse effect is suspected, baclofen should be tapered while remaining observant for signs of baclofen withdrawal, which can be life-threatening. This case report is a reminder for clinicians to be aware of the uncommon adverse effects of baclofen when initiating therapy in SCI, especially in patients with AKI and neurogenic bladders.

Estimating the National Population of Hospitalized Chronic Baclofen Users: A Cross-Sectional Analysis of a Commercial Claims Database

Background

Baclofen is an effective treatment for spasticity. Abrupt cessation of intrathecal (IT) or oral baclofen risks the development of withdrawal symptoms; however, the magnitude of the problem is unknown.

Objectives

The aims for this study were as follows: (1) using an administrative claims database, estimate the number of patients in the United States on baclofen, and (2) estimate the annual percent hospitalized pediatric and adult populations consequently at risk for interruption of chronic baclofen therapy.

Methods

Using 2011–2014 data representing commercially insured individuals, patients were selected based on insurance coverage; evidence of a baclofen claim; and hospitalization. All patients hospitalized while receiving chronic baclofen were assumed to be at risk for baclofen discontinuation. Yearly counts were determined and then extrapolated to national estimates using census data.

Results

Extrapolating from the claims database, oral or IT baclofen was prescribed annually to 33,061 or 1486 patients ≤ 18 years, and 654,294 or 7084 patients 19–64 years, respectively. The estimated national mean number of at-risk hospitalizations per year for patients aged 19–64 years on chronic oral or IT baclofen was 31,116 and 3774, respectively; patients ≤ 18 years numbered 4691 and 959, respectively. The mean percent of patients hospitalized per year was 42% in those ≤ 18 years receiving IT baclofen compared with 30% in adults, and 3–10% in the populations receiving oral baclofen.

Conclusions

Extrapolation from an administrative claims database was used to estimate the national number and demographics of hospitalized chronic baclofen users. Patients ≤ 18 years receiving IT baclofen were at highest risk of withdrawal due to a high occurrence of hospitalization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-022-00293-8.

Severe Case of Oral Baclofen Withdrawal Resulting in Mechanical Ventilation

Abrupt baclofen withdrawal may be life-threatening with varied neuropsychiatric manifestations. We present a case of baclofen withdrawal necessitating intubation. A 58-year-old female with a history of undiagnosed muscle spasticity presented with worsening extremities tremors, paresthesia, and weakness for 2 days. Initial vitals included temperature 103 F, tachycardia, hypertension, and tachypnea. Examination revealed coarse tremors of all extremities. Inflammatory markers, blood, and urine culture were negative. Head and spine imaging were non-diagnostic. Meningitis and seizure were ruled out. She continued worsening with hallucinations, hyperpyrexia, ocular clonus, and profound muscle rigidity. The patient was intubated for respiratory distress and transferred to intensive care unit (ICU). Further history revealed running out of oral baclofen 3 days ago. Baclofen was restarted with symptomatic improvement. The patient was extubated after 2 days and discharged to a rehabilitation facility. Oral or intrathecal baclofen is thought to inhibit spinal nerves reducing muscle spasm and pain. Abrupt stoppage causes activation of dopamine and noradrenergic receptors causing muscle spasms, tremors, hyperpyrexia, delusions, hallucination, and delirium. Severe cases can mimic meningoencephalitis, seizure disorder, or neuroleptic malignant syndrome. Symptoms usually develop in 1 to 3 days of cessation and can be life-threatening if unrecognized timely. Treatment includes supportive therapy, re-administration of baclofen, or use of benzodiazepines, propofol, dexmedetomidine; however, no specific guidelines have been established. To the knowledge of the authors, this is the first case of oral baclofen withdrawal requiring intubation. We found only 3 reported cases of intrathecal baclofen withdrawal necessitating intubation.

Multiple Electroencephalogram Recordings for Monitoring the Evolution of Neurological Complications during Baclofen Withdrawal Syndrome

Baclofen withdrawal syndrome represents a clinical emergency that can lead to life-threatening complications. It is often a diagnostic challenge because of its nonspecific nature of presentation and degree of symptom overlap with other clinical diseases. Electroencephalography (EEG) might provide important supporting evidence when neurological complications are involved. We present the case of a 55-year-old woman with sudden onset of motor manifestations at the limbs and an altered mental status 24 hours after cessation of intrathecal baclofen administration, following the removal of the pump due to infection, in whom a computed tomography did not show any acute-onset brain injuries, and multiple EEG recordings were performed. The first EEG showed the presence of bilateral sharply contoured waves, in the absence of epileptic discharges and seizures. No correlation between motor manifestations and EEG changes were detected. This EEG pattern was considered to be the expression of an overexcitation of the central nervous system (CNS) due to the loss of baclofen inhibitory effects, excluding an epileptic origin of motor manifestations. Another EEG, performed 24 hours later, showed the presence of triphasic waves with severe generalised slowing, suggesting the presence of encephalopathy. The last EEG, performed 48 hours after the previous recording, when a recovered state of consciousness was already present, showed regression of the triphasic waves and a reorganisation of the background activity. In our case, repeated EEG evaluation allowed monitoring the evolution of acute encephalopathy developed during baclofen withdrawal syndrome, from the initial phase of CNS hyperexcitability, through the phase of metabolic encephalopathy, and to its resolution. This modality allowed for optimising the diagnostic-therapeutic management of the patient during her stay in the intensive care unit.

Baclofen Withdrawal–Induced Psychosis in the Setting of Renal Insufficiency

Baclofen is used to treat muscle spasticity, acting at GABA B receptors in the central nervous system. The abrupt cessation of baclofen causes baclofen withdrawal–induced psychosis. The risk is exacerbated if the patient has renal insufficiency or if the drug has been taken for a long time at high doses. Gradual tapering of baclofen usually does not produce symptomatic adverse effects. However, abrupt termination of the drug, especially in an inpatient hospital setting, can lead to symptoms such as increased spasticity, agitation, confusion, hallucinations, and seizures. We present a case of a patient who initially presented with seizures and experienced hallucinations after abrupt cessation of the medication. She had baseline chronic kidney disease but presented with acute worsening of her renal function. Impaired renal function decreases baclofen clearance and causes increased concentration of baclofen in circulation. This put the patient at higher risk of developing baclofen withdrawal, even at a lower dose.

Probable Encephalopathy and Spasticity in a Multiple Sclerosis Patient Following Carbapenem Administration: A Case Report and Brief Literature Review

Purpose: The purpose of this case report is to describe spasticity and encephalopathy that developed in a multiple sclerosis patient following carbapenem administration. Summary: A 55-year-old female with multiple sclerosis developed spasticity and encephalopathy within 24 hours of meropenem and ertapenem administration. This was the second time that she had developed encephalopathy following carbapenem administration. The patient gradually recovered over four days following discontinuation of carbapenem therapy. Conclusion: Carbapenem neurotoxicity, a well-documented adverse effect, has been linked to several risk factors, including central nervous system lesions. Despite this, there is little evidence describing the risk of neurotoxicity in patients with multiple sclerosis. It is important to understand the potential adverse effects of carbapenems in specific patient populations to help guide appropriate treatment of infections.

In Support of Initial Parenteral Medical Management of Intrathecal Baclofen Withdrawal in Spasticity Patients

Background: Spasticity may present as a wide range of symptoms and conditions. With this protean presentation, a consensus regarding the best course of treatment does not exist. Those patients most severely affected may receive significant benefit from intrathecal baclofen delivery. However, this therapy may itself lead to patient injury in the event of withdrawal. Objective: Withdrawal from intrathecal baclofen may devolve rapidly into a situation in which the patient may incur significant morbidity and even death. A focused, prompt treatment plan would afford the patient the best possible outcome. Methods: The medical literature was reviewed for reports of plans of treatment of baclofen withdrawal and the results obtained. The nature of this problem does not lend itself to a typical study design, depending on case reports and basic pharmacological science application. The paucity of such reports severely limits categorical comparison of patient characteristics and clinical circumstances. Clinical situations, patient characteristics, and therapies were considered and compared. Outcomes of the varied treatments were evaluated for efficacy. Results: Inaccurate diagnoses, delayed correct diagnoses, and the absence of a consistent, treatment plan contributed to widely disparate outcomes. Prompt, correct diagnosis and intensive care unit-based continuous benzodiazepine infusion with titration led to a controlled clinical situation and maximized patient outcomes. Conclusions: Patients going through withdrawal from intrathecal baclofen achieved best outcomes when treated with a continuous infusion and titration of an intravenous benzodiazepine. A well-defined treatment protocol employing this management, reporting serial outcomes, would enable further refinement of the treatment of this clinical problem.

Prepontine placement of an intrathecal baclofen pump catheter for treatment of dystonia

Background:

Cerebral palsy with medically refractory spasticity and dystonia is a condition that often benefits from intrathecal baclofen pump therapy to treat these symptoms. In this case report, an intracranial baclofen catheter was placed in the prepontine space to improve withdrawal symptoms in a patient unable to undergo new lumbar catheter placement due to infection.

Case Description:

A 22-year-old female with past medical history of cerebral palsy presented with baclofen pump failure and was unable to undergo placement of a new lumbar baclofen catheter due to an infection in her lower back precluding safe and efficacious catheter placement. It was decided the patient would benefit from intrathecal baclofen administered in the prepontine space as a means to avoid a lumbar catheter and thus bypass this prior infection site. An endoscopic third ventriculostomy (ETV) was performed with the endoscope and the distal end of the baclofen pump catheter was fed through this ETV into the prepontine space. Placement in the prepontine space was confirmed by a follow-up head computed tomography. There was a significant improvement in autonomic symptoms and spasticity. By postoperative day 5, the patient was surgically and medically cleared for discharge.

Conclusion:

In cases of severe baclofen withdrawal due to dysfunctional pumps, immediate reversal is preferred but may not be feasible due to factors such as infection. This case report has demonstrated that prepontine catheter placement can be effective for the administration of baclofen to reverse withdrawal symptoms in these types of patients.

Recommendations from the EXTRIP workgroup on extracorporeal treatment for baclofen poisoning

Baclofen toxicity results from intentional self-poisoning ("acute baclofen poisoning") or accumulation of therapeutic dose in the setting of impaired kidney function. Standard care includes baclofen discontinuation, respiratory support and seizure treatment. Use of extracorporeal treatments (ECTRs) is controversial. To clarify this, a comprehensive review of the literature on the effect of ECTRs in baclofen toxicity was performed and recommendations following EXTRIP methods were formulated based on 43 studies. (1 comparative cohort, 1 aggregate results cohort, 1 pharmacokinetic modeling, and 40 patient reports or series). Toxicokinetic data were available for 20 patients. Baclofen's dialyzability is limited by a high endogenous clearance and a short half-life in patients with normal kidney function. The workgroup assessed baclofen as "Moderately dialyzable" by intermittent hemodialysis for patients with normal kidney function (quality of evidence C) and "Dialyzable" for patients with impaired kidney function (quality of evidence C). Clinical data were available for 25 patients with acute baclofen poisoning and 46 patients with toxicity from therapeutic baclofen in kidney impairment. No deaths or sequelae were reported. Mortality in historical controls was rare. No benefit of ECTR was identified in patients with acute baclofen poisoning. Indirect evidence suggests a benefit of ECTR in reducing the duration of toxic encephalopathy from therapeutic baclofen in kidney impairment. These potential benefits were balanced against added costs and harms related to the insertion of a catheter, the procedure itself, and the potential of baclofen withdrawal. Thus, the EXTRIP workgroup suggests against performing ECTR in addition to standard care for acute baclofen poisoning and suggests performing ECTR in toxicity from therapeutic baclofen in kidney impairment, especially in the presence of coma requiring mechanical ventilation.

Baclofen therapeutics, toxicity, and withdrawal: A narrative review

Baclofen is an effective therapeutic for the treatment of spasticity related to multiple sclerosis, spinal cord injuries, and other spinal cord pathologies. It has been increasingly used off-label for the management of several disorders, including musculoskeletal pain, gastroesophageal reflux disease, and alcohol use disorder. Baclofen therapy is associated with potential complications, including life-threatening toxicity and withdrawal syndrome. These disorders require prompt recognition and a high index of suspicion. While these complications can develop following administration of either oral or intrathecal baclofen, the risk is greater with the intrathecal route. The management of baclofen toxicity is largely supportive while baclofen withdrawal syndrome is most effectively treated with re-initiation or supplementation of baclofen dosing. Administration of other pharmacologic adjuncts may be required to effectively treat associated withdrawal symptoms. This narrative review provides an overview of the historical and emerging uses of baclofen, offers practical dosing recommendations for both oral and intrathecal routes of administration, and reviews the diagnosis and management of both baclofen toxicity and withdrawal.

Oral Baclofen Withdrawal Resulting in Hyperactive Delirium: A Case Report

Baclofen is used in the treatment of muscle spasms by acting as an agonist GABA_B receptors. Limited case reports describing baclofen withdrawal-induced delirium have largely been demonstrated to occur upon cessation of intrathecal baclofen administration. Fewer reports have characterized the presentation from oral baclofen withdrawal. We describe a case of a patient, MM, who presented with hyperactive delirium with various, associated, behavioral, perceptual, cognitive, and movement disturbances following abrupt withdrawal of oral baclofen. Symptomatic management of occurring during the withdrawal state with antipsychotics and benzodiazepines has been reported previously. Similarly, MM's perceptual and behavioral disturbances were managed with antipsychotics during her admission. However, addressing the underlying cause by reinstating and slowly tapering off baclofen has also been demonstrated to be an effective, targeted approach.

GABAergic Mechanisms Can Redress the Tilted Balance between Excitation and Inhibition in Damaged Spinal Networks

Correct operation of neuronal networks depends on the interplay between synaptic excitation and inhibition processes leading to a dynamic state termed balanced network. In the spinal cord, balanced network activity is fundamental for the expression of locomotor patterns necessary for rhythmic activation of limb extensor and flexor muscles. After spinal cord lesion, paralysis ensues often followed by spasticity. These conditions imply that, below the damaged site, the state of balanced networks has been disrupted and that restoration might be attempted by modulating the excitability of sublesional spinal neurons. Because of the widespread expression of inhibitory GABAergic neurons in the spinal cord, their role in the early and late phases of spinal cord injury deserves full attention. Thus, an early surge in extracellular GABA might be involved in the onset of spinal shock while a relative deficit of GABAergic mechanisms may be a contributor to spasticity. We discuss the role of GABA A receptors at synaptic and extrasynaptic level to modulate network excitability and to offer a pharmacological target for symptom control. In particular, it is proposed that activation of GABA A receptors with synthetic GABA agonists may downregulate motoneuron hyperexcitability (due to enhanced persistent ionic currents) and, therefore, diminish spasticity. This approach might constitute a complementary strategy to regulate network excitability after injury so that reconstruction of damaged spinal networks with new materials or cell transplants might proceed more successfully.

Regulation of Glutamatergic Activity via Bidirectional Activation of Two Select Receptors as a Novel Approach in Antipsychotic Drug Discovery

Schizophrenia is a mental disorder that affects approximately 1-2% of the population and develops in early adulthood. The disease is characterized by positive, negative, and cognitive symptoms. A large percentage of patients with schizophrenia have a treatment-resistant disease, and the risk of developing adverse effects is high. Many researchers have attempted to introduce new antipsychotic drugs to the clinic, but most of these treatments failed, and the diversity of schizophrenic symptoms is one of the causes of disappointing results. The present review summarizes the results of our latest papers, showing that the simultaneous activation of two receptors with sub-effective doses of their ligands induces similar effects as the highest dose of each compound alone. The treatments were focused on inhibiting the increased glutamate release responsible for schizophrenia arousal, without interacting with dopamine (D₂) receptors. Ligands activating metabotropic receptors for glutamate, GABA_B or muscarinic receptors were used, and the compounds were administered in several different combinations. Some combinations reversed all schizophrenia-related deficits in animal models, but others were active only in select models of schizophrenia symptoms (i.e., cognitive or negative symptoms).

Enteral baclofen withdrawal managed with intravenous dexmedetomidine: A case report

PURPOSE

Acute enteral baclofen withdrawal can be clinically severe if not identified and managed appropriately. Treatment of baclofen withdrawal includes supportive care and reinitiation of baclofen. There are limited pharmacotherapeutic interventions available to manage symptoms of acute enteral baclofen withdrawal, especially in nonintubated patients.

SUMMARY

We describe a 61-year-old Caucasian male with a past medical history of chronic back pain and spinal stenosis who was admitted to the medical intensive care unit with confusion, insomnia, agitation, delirium, and auditory and visual hallucinations. For control of agitation, the patient was administered 10 mg of i.v. haloperidol, 1 mg of i.v. lorazepam, and 14 mg of i.v. midazolam, with minimal improvement noted; therefore, dexmedetomidine was initiated, which led to clinical resolution of his symptoms. Upon further investigation it was determined that the patient was taking approximately 10 baclofen 20-mg tablets a day. According to his pharmacy records, he had filled prescriptions for a total of 738 baclofen tablets in the previous 12 weeks. The patient's presentation and sudden discontinuation of high-dose baclofen led to a diagnosis of baclofen withdrawal. Baclofen was subsequently restarted, and dexmedetomidine was weaned over 36 hours.

CONCLUSION

Dexmedetomidine controlled this patient's agitation and delirium without suppressing his respiratory drive and should be considered for management of acute enteral baclofen withdrawal.

Safety and Tolerability of the Anxiolytic and Nootropic Drug Phenibut: A Systematic Review of Clinical Trials and Case Reports

Phenibut is a nootropic drug that exerts anxiolytic and antinociceptive effects by acting on the GABA_B receptor and the α₂-δ subunit of voltage-dependent calcium channels. An increased number of reports of dependence to and intoxication by phenibut purchased online on the one hand and the wide prescription of phenibut in Eastern Europe for more than half a century on the other hand have resulted in a number of controversies regarding its use. In this review, we have summarized currently available information from case reports of phenibut dependence and intoxication and safety data from clinical trials. We included 14 dependence and intoxication case reports (16 patients) and reviewed 11 phenibut clinical trials (583 patients). The clinical symptoms in the case reports included cardiovascular effects, insomnia, anxiety and agitation, hallucinations, and depressed level of consciousness. In addition, the doses used (0.5-100 g/day) were much higher than the recommended daily dose (0.25-2 g/day). An analysis of phenibut side effects described in the clinical trials showed adverse events in only 5.66% of patients, and the most reported side effect was somnolence (1.89%). There are discrepancies in the reported side effects of phenibut in clinical trials compared to those reported in cases of online-purchased phenibut dependence and intoxication. The current systematic review provides evidence that, at therapeutic doses, phenibut is safe and well tolerated with minor adverse effects, but questions regarding the quality of phenibut obtained online and the contribution of alcohol and other drug abuse to phenibut dependence and intoxication remain open.

Drug deprescription-withdrawal risk, prevention, and treatment

In most cases, a sudden interruption of most medications has no major consequences. There are well-recognized therapies that, when withheld, can either lead to the reappearance of the symptoms they were controlling or to signs or symptoms of withdrawal. In this article, we present a table including medications that when interrupted can produce withdrawal syndromes, the signs and symptoms of the withdrawal syndrome, the time to onset and resolution of the syndrome, information regarding alternative delivery options for the drug/s when the oral route is not possible, as well as prevention and therapy.

Intrathecal Baclofen Injection to Avoid Withdrawal in a Multiple Sclerosis Patient Undergoing Lumbar Spine Surgery: A Case Report

Spasticity of spinal or cerebral origin is frequently treated with baclofen. Treatment interruption initially results in rebound spasticity; life-threatening withdrawal symptoms may follow. Severe rebound spasticity of leg muscles occurred in a multiple sclerosis patient after a 10-hour long perioperative pause of oral baclofen intake. In a subsequent spine surgery, recurrence was prevented by substituting a cumulative 12-hour oral baclofen dose with an intraoperative intrathecal injection. Administration of intrathecal baclofen during prolonged surgery in patients dependent on oral baclofen may improve patient comfort and prevent early withdrawal symptoms. The most optimal conversion ratio from oral to intrathecal baclofen is still undetermined.

Management of Tizanidine Withdrawal Syndrome: A Case Report

Most drugs that act on the central nervous system (CNS) require dose titration to avoid withdrawal syndrome. Tizanidine withdrawal syndrome is caused by adrenergic discharge due to its α₂-agonist mechanism and is characterized by hypertension, reflex tachycardia, hypertonicity, and anxiety. Although tizanidine withdrawal syndrome is mentioned as a potential side effect of cessation, it is not common and there have been few reports. We present the case of a 31-year-old woman with tizanidine withdrawal syndrome after discontinuing medication prescribed for a muscle contracture (tizanidine). She showed high adrenergic activity with nausea, vomiting, generalized tremor, dysthermia, hypertension, and tachycardia. Symptoms were reversed and successful reweaning was achieved by restarting tizanidine followed by slow downward titration. Withdrawal syndrome should be considered when drugs targeting the CNS are suddenly stopped. Weaning regimens should be closely monitored for acute withdrawal reactions.

Early outcomes after intrathecal baclofen therapy in ambulatory patients with multiple sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a chronic autoimmune disease that causes demyelination and axonal loss. Walking difficulties are a common and debilitating symptom of MS; they are usually caused by spastic paresis of the lower extremities. Although intrathecal baclofen (ITB) therapy has been reported to be an effective treatment for spasticity in MS, there is limited published evidence regarding its effects on ambulation. The goal of this study was to characterize ITB therapy outcomes in ambulatory patients with MS.

METHODS

Data from 47 ambulatory patients with MS who received ITB therapy were analyzed retrospectively. Outcome measures included Modified Ashworth Scale, Spasm Frequency Scale, Numeric Pain Rating Scale, and the Timed 25-Foot Walk. Repeated-measures ANOVA was used to test for changes in outcome measures between baseline and posttreatment (6 months and 1 year). Significance was set at p < 0.05. Descriptive data are expressed as the mean ± SD, and results of the repeated-measures ANOVA tests and the Wilcoxon rank-sum test are expressed as the mean ± SEM.

RESULTS

There was a statistically significant reduction in the following variables: 1) aggregate lower-extremity Modified Ashworth Scale scores (from 14.8 ± 1.0 before ITB therapy to 5.8 ± 0.8 at 6 months posttreatment and 6.4 ± 0.9 at 1 year [p < 0.05]); 2) Numeric Pain Rating Scale scores (4.4 ± 0.5 before ITB, 2.8 ± 0.5 at 6 months, and 2.4 ± 0.4 at 1 year [p < 0.05]); 3) spasm frequency (45.7% of the patients reported a spasm frequency of ≥ 1 event per hour before ITB therapy, whereas 15.6% and 4.3% of the patients reported the same at 6 months and 1 year posttreatment, respectively [p < 0.05]); and 4) the number of oral medications taken for spasticity (p < 0.05). Of the 47 patients, 34 remained ambulatory at 6 months, and 32 at 1 year posttreatment. There was no statistically significant change in performance on the Timed 25-Foot Walk test over time for those patients who remained ambulatory.

CONCLUSIONS

In this retrospective study, the authors found that ITB therapy is effective in reducing spasticity and related symptoms in ambulatory patients with MS. Because the use of ITB therapy is increasing in ambulatory patients with MS, randomized, prospective studies are important to help provide a more useful characterization of the effects of ITB therapy on ambulation.

Baclofen Overdose Presenting as Psychosis with Catatonia

Baclofen is a centrally acting gamma-aminobutyric acid receptor agonist with many therapeutic uses in neurology and psychiatry. An overdose of baclofen is known to cause serious side effects such as encephalopathy, seizures, respiratory depression, and delirium. Association of baclofen with psychosis has also been reported. In this case report, we are highlighting the manifestation of catatonic features in addition to psychosis following baclofen overdose.

Potential for Intrathecal Baclofen in Treatment of Essential Tremor

INTRODUCTION

Essential tremor (ET) is the most common movement disorder of adults, affecting an estimated 7 million Americans. Symptoms of ET range from slightly noticeable to debilitating, with 1 cohort study finding 15% of patients were forced into early retirement. Additionally, depression has also been correlated with the severity of disability of ET. Treatment options include propranolol and primidone. Current treatment options are not very effective, with more than half (56.3%) of patients discontinuing medications because of no changes in symptoms.

METHODS

Unfortunately, there is a relative void and controversy in the literature explaining ET pathophysiology; however, the gamma-aminobutyric acid (GABA) hypothesis is the strongest. We conducted a PubMed search on 30 September 2015 with no time constraints using the search terms "essential tremor" and "baclofen," which resulted in a total of 5 articles.

RESULTS

Neurohistopathologic studies have demonstrated decreased GABA-A and GABA-B receptors in the cerebellar cortex of ET patients. GABA, the major inhibitory neurotransmitter in the central nervous system, is proposed to have an inhibitory effect on pacemaker output activity of the cerebello-thalamo-cortical pathway, with lower receptors resulting in decreased inhibition of baseline tremors. Tariq et al showed delayed onset and intensity of tremor with oral administration of R-baclofen in a mouse model of ET.

CONCLUSION

With a better side-effect profile and success in a physiologically related condition, we propose more clinical trials and research be carried out on intrathecal baclofen as a potential treatment option, especially drug refractory ET, so as to increase the quality of life of this patient population.

Baclofen-Induced Psychosis

Objective:

To report a case of psychosis induced by therapeutic doses of baclofen.

Case Summary:

A 32-year-old Hindu man was prescribed oral baclofen 10 mg twice daily for relief of muscular spasms secondary to tetanus. After 4 weeks of baclofen use, he presented to the psychiatry emergency facility with a 4 day history of third-person auditory hallucinations and persecutory and referential delusions without underlying mood symptoms. These symptoms resolved within 1 week of discontinuing baclofen. Rechallenge with baclofen resulted in reemergence of psychotic symptoms, which disappeared after discontinuing baclofen.

Discussion:

Reemergence of psychotic symptoms after rechallenge with baclofen suggests baclofen-induced psychosis. Use of the Naranjo probability scale indicates a probable association of baclofen with this patient's psychosis. The absence of underlying mood disorder makes this case different from previously reported ones.

Conclusions:

Baclofen may be associated with the occurrence of psychosis. Clinicians should consider baclofen-induced psychosis as a differential diagnosis in patients presenting with psychosis during treatment with this drug.

Is it time for baclofen to be included in the official recommendations concerning the treatment of alcoholism?

Alcohol dependence and its treatment is not an exactly resolved problem. Based on the EZOP [Epidemiology of Mental Disorders and Accessibility of Mental Health Care] survey, which included a regular analysis of the incidence of mental disorders in the population of adult Polish citizens, we were able to estimate that the problem of alcohol abuse in any period of life affects even 10.9% of the population aged 18-64 years, and those addicted represent 2.2% of the country’s population. The typical symptoms of alcohol dependence according to ICD-10, include alcohol craving, impaired ability to control alcohol consumption, withdrawal symptoms which appear when a heavy drinker stops drinking, alternating alcohol tolerance, growing neglect of other areas of life, and persistent alcohol intake despite clear evidence of its destructive effect on life. At the moment, the primary method of alcoholism treatment is psychotherapy. It aims to change the patient’s habits, behaviours, relationships, or the way of thinking. It seems that psychotherapy is irreplaceable in the treatment of alcoholism, but for many years now attempts have been made to increase the effectiveness of alcoholism treatment with pharmacological agents. In this article we will try to provide a description of medications which help patients sustain abstinence in alcoholism therapy with particular emphasis on baclofen.

Oral Baclofen Withdrawal Resulting in Progressive Weakness and Sedation Requiring Intensive Care Admission

Baclofen is a common medication used as a muscle relaxant and antispasmodic. Baclofen-withdrawal syndrome has many symptoms such as sedation, somnolence, and weakness but can include psychological symptoms. We present a 62-year-old female whose oral baclofen was not continued at a skilled nursing facility after discharge following inpatient surgery that led to the development of altered mental status and respiratory insufficiency necessitating intensive care unit admission. Abrupt cessation of baclofen, no matter the mode of administration to the patient, can lead to baclofen-withdrawal syndrome.

Baclofen pump catheter leakage after migration of the abdominal catheter in a pediatric patient with spasticity

The authors report an unusual case of intrathecal baclofen withdrawal due to the perforation and subsequent leakage of a baclofen pump catheter in a patient with spastic cerebral palsy. A 15-year-old boy underwent an uncomplicated placement of an intrathecal baclofen pump for the treatment of spasticity due to cerebral palsy. After excellent control of symptoms for 3 years, the patient presented to the emergency department with increasing tremors following a refill of his baclofen pump. Initial evaluation consisted of radiographs of the pump and catheter, which appeared normal, and a successful aspiration of CSF from the pump's side port. A CT dye study revealed a portion of the catheter directly overlying the refill port and extravasation of radiopaque dye into the subfascial pocket anterior to the pump. During subsequent revision surgery, a small puncture hole in the catheter was seen to be leaking the drug. The likely cause of the puncture was an inadvertent perforation of the catheter by a needle during the refilling of the pump. This case report highlights a unique complication in a patient with an intrathecal baclofen pump. Physicians caring for these patients should be aware of this rare yet potential complication in patients presenting with baclofen withdrawal symptoms.

Roux-en-Y gastric bypass for intractable biliary reflux in an individual with incomplete tetraplegia

CONTEXT

Gastroesophageal reflux disease (GERD) is a common complication in the spinal cord injury (SCI) population. Surgical treatment of GERD has a unique risk/benefit profile in this population.

FINDINGS

This 68-year-old male with chronic incomplete tetraplegia, dyslipidemia, and well-controlled diabetes mellitus underwent Roux-en-Y gastric bypass surgery (RYGBP) for intractable biliary reflux. Postoperatively, the patient had resolution of his symptoms but he also presented with significant weight loss and dumping syndrome. While he did have improvement in his dyslipidemia there was no change in his functional status.

CONCLUSIONS

RYGBP is an option for refractory GERD treatment in the SCI population but preoperative risk assessment and close monitoring postoperatively is essential.

Tolerability of High-dose Baclofen in the Treatment of Patients with Alcohol Disorders: A Retrospective Study

AIMS

The aim of this study was to describe the tolerability of high-dose baclofen taken by patients with alcohol disorders during their first year of treatment.

METHODS

The medical records of all patients prescribed baclofen by one general practitioner were examined and all patients who could be contacted were retrospectively interviewed about adverse effects.

RESULTS

Of the 146 eligible patients, 116 (79%) could be interviewed. Ninety (78%) reported at least one adverse effect (mean number per patient: 2.8 ± 2.7). The mean dosage of baclofen at the onset of the first adverse effect was 83 ± 57 mg/day. The most frequent group of adverse effects involved disruption of the wake-sleep cycle and affected 73 patients (63%). Persistent adverse effects occurred in 62 patients (53%). Eight patients (7%) had adverse effects that led them to stop taking baclofen. Their dosages were <90 mg/day at that time. Alertness disorders and depression were the adverse effects that most frequently led to stopping baclofen. Bouts of somnolence and hypomanic episodes were the most potentially dangerous adverse effects. Women reported significantly more adverse effects than men.

CONCLUSION

High-dose baclofen exposes patients with alcohol disorders to many adverse effects. Generally persistent, some adverse effects appear at low doses and may be dangerous.

Baclofen as relapse prevention in the treatment of gamma-hydroxybutyrate dependence: a case series

In the last decade, gamma-hydroxybutyrate (GHB) abuse and dependence have increased. It has been reported that GHB dependence has a high rate of relapse, serious complications of intoxication, and a potentially life-threatening withdrawal syndrome. Nevertheless, in clinical practice, there is no known medical treatment to support GHB relapse prevention. We describe a case series of patients who were supported through an off-label treatment with baclofen to avoid a relapse into GHB abuse, for a period of 12 weeks. Nine of 11 patients did not relapse while taking a dose ranging from 30 to 60 mg per day, one patient relapsed after 5 weeks, and one stopped after 7 weeks. Baclofen was well tolerated; patients reported mild side effects such as fatigue, nausea, dry mouth, excessive sweating, and depressive feelings. Although systematic evidence is still lacking, our practice-based experience suggests that treatment with baclofen to assist abstinence might be effective in patients with GHB dependence. Further systematic controlled studies are necessary to establish the exact efficacy and safety of baclofen as relapse prevention for GHB-dependent patients.

Baclofen as relapse prevention in the treatment of Gamma- Hydroxybutyrate (GHB) dependence: an open label study

BACKGROUND

GHB dependence is a growing health problem in several western countries, especially the Netherlands. Attempts to stop using GHB are often followed by relapse shortly after successful detoxification. Craving for GHB use and co-morbid psychiatric symptom levels are thought to be the major factors contributing to the high relapse rates. Given its pharmacological profile, baclofen might prove an effective anti-craving agent for patients with GHB dependence. The aim of the current study is to assess the potential of baclofen as an anti-craving agent relapse prevention intervention in GHB dependent patients.

METHODS/DESIGN

In an open label non-randomized trial treatment with baclofen to a maximum of 60 mg/day will be compared with treatment as usual (TAU) in recently detoxified GHB dependent patients (n = 80). The primary outcome measure will be the level of GHB use. Secondary outcome measures are craving levels, psychiatric symptom levels and quality of life. Questionnaires will be administered during 12 weeks of baclofen treatment and at follow-up (six months after the start of treatment).

DISCUSSION

It is hypothesized that baclofen treatment compared to TAU will be associated with significantly reduced GHB use. In addition, we hypothesize that baclofen treatment will be associated with decreased craving and anxiety levels, and higher quality of life. If results are in line with our hypotheses, further studies on the efficacy of baclofen using placebo controlled designs and long term follow-up are warranted.

TRIAL REGISTRATION

The Netherlands Trial Register with number NTR4528 . Registered 19 April 2014.

Use of baclofen for withdrawal in a preterm infant

Baclofen is a gamma-aminobutyric acid agonist used primarily as a muscle relaxant to treat spasticity in children and adults. Withdrawal of oral baclofen is known to cause a withdrawal syndrome in adults. Only one previous case describes a withdrawal syndrome in a term infant, manifested by seizures, associated with the use of oral baclofen in the mother. This case describes a withdrawal syndrome and the unique use of baclofen for withdrawal in a preterm infant.

Efficacy and tolerability of baclofen in substance use disorders: a systematic review

BACKGROUND

It has been reported that baclofen, a drug used in the treatment of spasticity, reduces the severity of withdrawal symptoms and substance use disorders (SUDs) for some psychoactive drugs.

AIMS AND METHODS

To evaluate the effectiveness and safety of baclofen in the treatment of withdrawal syndrome and/or SUDs, providing (1) an outline of its pharmacological features; (2) a summary of studies that have suggested its possible effectiveness in the treatment of SUDs, and (3) a review of randomized, controlled trials (RCTs) on baclofen and SUDs.

RESULTS

Baclofen tolerability is generally considered to be good. Eleven RCTs investigated its effectiveness in the treatment of SUDs. Of these, 5 RCTs found that baclofen is effective, 5 RCTs found that it is ineffective and the results of 1 RCT were not appreciable because it did not achieve the preplanned level of participation.

CONCLUSIONS

The number of RCTs on baclofen and SUDs is still low, and their results are divergent. Further RCTs should be undertaken, particularly with higher doses of baclofen. Its administration may be suggested in patients who fail to respond to other approved drugs or who are affected by liver disease that prevents their administration, or in patients affected by SUDs for which no approved drugs are available. Treatment should be conducted under strict medical supervision.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.