Coma and Respiratory Failure in a 2-Year-Old Child After Accidental Overdose of Baclofen

Baclofen (Lioresal) is a derivative of gamma-aminobutyric acid and is used in both adults and children mainly for symptomatic treatment of muscle spasticity. It is absorbed completely from the gastrointestinal tract, metabolized minimally in the liver and is excreted almost unchanged by the kidneys. Being lipophilic it can cross the blood-brain barrier easily. Baclofen overdose can result in life threatening complications such as respiratory failure, metabolic encephalopathy, seizures, deep coma and autonomic instability leading to hypertension and bradycardia.1-5 The literature on oral baclofen overdose in young children is very sparse. Here we report a 2-year-old-girl who was found by her parents after an accidental ingestion of her father's baclofen. The child presented with respiratory failure, coma, hypotonia and bradycardia. The patient was managed conservatively; mechanically ventilated for 16 hours and was discharged home after 48 hours with no sequelae.

Correlation between the single, high dose of ingested baclofen and clinical symptoms

INTRODUCTION AND OBJECTIVES

Baclofen is a drug used mainly to treat muscle spasticity. Its overdose can lead to life-threatening clinical symptoms, including acute respiratory failure requiring mechanical ventilation. The aim of this study was to assess the prevalence of selected clinical symptoms associated with baclofen poisoning comparing to an ingested dose.

MATERIAL AND METHODS

60 cases of oral baclofen poisoning were analyzed. Gender, age distribution, and correlation between the dose of ingested baclofen were studied, as well as and following clinical parameters: degree of altered consciousness, heart rate, blood pressure, presence of acute respiratory failure, duration of mechanical ventilation, and presence of psychotic symptoms.

RESULTS

The study found statistically significant correlations between dosage of ingested baclofen and presence of acute respiratory failure, as well as duration of mechanical ventilation. No statistically significant correlations were found between the dose of ingested baclofen and presence of hypertension, bradycardia, acute psychotic symptoms, or level of consciousness disturbance. However, it was found that patients who suffered from hypertension, bradycardia, and altered mental status ingested a larger dose of baclofen.

CONCLUSIONS

There is a statistically significant correlation between the dose of ingested baclofen and the presence of acute respiratory failure, and duration of mechanical ventilation. Patients who have taken a single dose of baclofen of 200 mg, or higher, should be managed in centres able to provide continuous monitoring of life functions. Those with a higher level of a single dose of baclofen ingestion (>500 mg), should be hospitalized in a Toxicology Unit or Intensive Care Unit able to provide airway support and mechanical ventilation.

[Aggression and restlessness following baclofen overdose: the narrow line between intoxication and withdrawal symptoms]

BACKGROUND

Baclofen is increasingly prescribed for alcohol dependency. Subsequently, the risk of self-intoxication with this medicinal product is increasing.

CASE DESCRIPTION

A 23-year-old man with a history of alcohol dependence was admitted to our hospital after self-intoxication with 2700 mg baclofen and 330 mg mirtazapine. Respiratory insufficiency as a result of the baclofen intoxication required intubation and admission to the ICU. During the first day, despite the use of sedatives, the patient became intermittently agitated and aggressive. In the following days, he developed severe delirium, probably due to baclofen withdrawal. The reintroduction of baclofen quickly resolved these symptoms.

CONCLUSION

In the case of baclofen, in practice it is difficult to differentiate between intoxication and withdrawal. To prevent potentially severe withdrawal symptoms, we recommend reintroduction of baclofen when the first signs of restlessness and agitation arise following intoxication.

Increase of baclofen intoxications: risks involved and management

Baclofen has been increasingly used in the treatment of alcohol withdrawal syndrome (AWS). We present a patient with AWS and psychiatric comorbidity who ingested 700 mg of baclofen. ICU admission was necessary for ventilatory support and symptomatic treatment. The patient was dismissed without sequelae.

[Venovenous hemodiafiltration for patient with baclofen intoxication]

Twice a young man was admitted to hospital upon having taken baclofen overdoses by intention. The ingested dose was 1,850 mg at the first episode and up to 2,500 mg at the second. In both cases the patient had severe overdose symptoms and scored 4-5 on the Glascow Coma Scale and was admitted to intensive care. Continuous venovenous hemodiafiltration (CVVHDF) was initiated. The elimination pharmacokinetics and toxicokinetics for baclofen is not fully known. During the second submission a shorter elimination half-life time was observed and it might be due to either compartmental distribution of baclofen, or more likely caused by an advantageous effect of the CVVHDF.

[Clinical characteristics, diagnosis, and treatment of acute intoxication by baclofen]

For last few years in Russia and in the Armed Forces of RF is marked a growth of number of acute intoxications by GABA-agonists and by muscle relaxants, particularly by baclofen. Manifestations of intoxication by this specimen include cerebral and somatic-vegetal disorders, in grave cases of illness could evolve psychic excitement, delusions and coma. Treatment of baclofen intoxication compares of gastric lavage using a thick pathfinder, accompanied by insertion of adsorbent and apocathartic means, maintaining of impaired vital functions of body. Hereafter these injured patients should be hospitalized in a treatment institute, where exists a possibility of effectuating of reanimation and intensive care as well as extracorporal detoxication (hemosorption, hemodialysis).

[Misuse of substances theoretically without abuse potential--case series]

The aim of our study was to present cases of misuse of different substances theoretically without abuse potential. In the last few years such behavior became an increasing problem in toxicological and emergency units. Lack of typical signs of intoxication with psychoactive substances, and negative results of standard toxicological tests may be a challenge for toxicologists and emergency medicine practitioners.

Prolonged unconsciousness in a patient on automated peritoneal dialysis

A 79-year-old man with end-stage renal disease treated by automated peritoneal dialysis was referred to the emergency department for altered consciousness. The first investigations, including toxicology screening, failed to reveal the precise etiology. The patient was treated for a possible seizure. After the progression of central nervous system depression with bradypnea, the patient was intubated and mechanically ventilated. It appeared later on that he had ingested by mistake one of his wife's medications, baclofen. Baclofen was detected in the blood sampled on admission at a level above the therapeutic range. Baclofen is mainly excreted by the kidney. A short-term administration of low-dose of baclofen is not effectively removed by peritoneal dialysis and may result in prolonged but reversible coma.

Baclofen overdose: defining the spectrum of toxicity

OBJECTIVES

To describe the spectrum of toxicity of baclofen in overdose, and investigate dose-related clinical effects.

METHODS

Consecutive baclofen overdoses were identified from a prospective database of all poisoning admissions presenting to a regional toxicology service. Ingestion was corroborated on more than one occasion and from multiple sources. Demographic, clinical and outcome variables were extracted for each presentation for a retrospective review, and the data sets were divided into high dose (> or = 200 mg) and low dose (< 200 mg) groups for comparison of clinical effects.

RESULTS

There were 23 presentations, of which eight patients ingested baclofen alone. Seizures were reported in four cases, a decreased level of consciousness (GCS < 9) occurred in eight patients and delirium was recorded in eight patients. Five patients had miosis and seven patients had dilated pupils, 13 patients had absent or depressed reflexes. The only arrhythmias were sinus bradycardia in six patients and sinus tachycardia in five. Hypertension occurred in 13 patients and hypotension in one. The reported total ingested dose of baclofen was known in 19 patients (Mean 630 mg, SD 730 mg; 80-2500 mg). A higher ICU admission rate, rate of mechanical ventilation and prolonged length of stay occurred in those ingesting 200 mg or more. Coma, delirium and seizures occurred only with doses of 200 mg or more, and hypertension was more common with higher doses.

CONCLUSIONS

Baclofen overdose causes mainly neurological effects and excepting hypertension cardiovascular effects were uncommon. Doses greater than 200 mg were predictive of patients developing delirium, coma and seizures, requiring long hospital admissions and ICU admission.

Apport de l'EEG dans le diagnostic d'une intoxication au baclofène

In a young woman presenting with severe coma, the EEG helped diagnosing baclofen overdose. In this patient, the first EEG showed continuous multifocal pseudoperiodic sharp waves. The diagnosis was confirmed by the plasma dosage providing an 8-fold increase above normal baclofen therapeutic range. Following symptomatic therapy, the patient improved within a few days and the EEG normalised. Few other drugs may be responsible for such EEG changes, namely lithium, cephalosporin, and bismuth. In such cases, EEG contribution to the diagnosis should not be ignored.

Magnetic resonance spectroscopy and electroencephalography in baclofen coma

This report describes a 14-year-old female who presented with coma and seizures. Continuous electroencephalographic monitoring revealed suppression and semiperiodic sharp waves. Magnetic resonance spectroscopy performed 1 day after admission suggested a good outcome despite her clinical examination and electroencephalogram. She was subsequently found to have elevated serum baclofen levels after an intentional overdose. At the time of her discharge from the pediatric intensive care unit, she manifested no neurologic deficits, and on telephone follow-up 2 years after the ingestion the patient had no complaints of any cognitive problems or neurologic dysfunction.

Intrathecal baclofen overdose followed by withdrawal: clinical and EEG features

Intrathecal baclofen therapy is increasingly used to alleviate medically intractable spasticity in children with cerebral palsy, spinal cord injuries, and generalized dystonia. Complications like overdose or withdrawal can occur and could be the result of pump malfunction (device-related) or refilling and programming mistakes (human errors). This report describes a case, with emphasis on electroencephalographic changes, of a 12-year old male on long-term intrathecal baclofen therapy who had sequential occurrence of both acute inadvertent baclofen overdose followed by withdrawal symptoms. During baclofen intoxication, electroencephalography documented periodic generalized epileptiform discharges, occasionally followed by intermittent electro-decremental responses on a background of diffuse delta slowing (1-2 Hz). During withdrawal, mild generalized slowing during wakefulness was observed along with the appearance of high-amplitude, sharply contoured delta activity resembling frontal intermittent rhythmic delta activity in sleep. To our knowledge, this temporal profile of electroencephalographic features during baclofen intoxication followed by withdrawal has not been described before in pediatric patients. It is important for treating physicians to recognize the evolution of this electroencephalographic pattern in order to avoid misinterpretation of diagnosis and prognosis.

An unusual presentation of baclofen overdose

Baclofen has become increasingly popular in the treatment of spasticity disorders. Its availability for misuse has also increased. We report a case of baclofen overdose in a 20-year-old man, who manifested atypical symptoms of baclofen overdose--that is, delirium and rhabdomyolysis. He was treated successfully with full supportive management, and was discharged from the hospital on the 12th day following admission. If a past medication history is not immediately available, baclofen overdose should be included in the differential diagnosis of an acutely confused patient complicated with rhabdomyolysis, as routine toxicology screening does not include baclofen.

[Baclofen-intoxication in a child resulting in coma, bradycardia and transitory defect of visual power]

A twelve and a half year old girl of foreign nationality was been found in her domestic environment in unwakeable condition. The emergency was alarmed, and she was transferred to the children's hospital. Her condition at this time: she was unconscious and suffering from cold sweat but her circulation was stable and her respiration sufficient. Because of language barriers it was difficult to find out the antecedence of her state, but an empty box of pills (Amitryptilin) lying next to the patient may serve as a first hint to a intoxication. The father denied that his daughter might have consumed drugs or alcohol and meant that any abuse of medicine was out of the question. First urinary measurements to check if any drugs might be involved remain inconspicuous; in a control measurement of the blood 12 hours later only an elevation of the CPK is noticed as an unusual detail. The CPK-MB remains being according to normal. The native CT of the skull remains inconspicuous as well as the control with contrastation after 12 hours and a MRT-examination after 36 hours. The liquor punction does not give hints to any pathological facts. The EEG shows a high degree of continuous irregular slowe waves over both hemispheres in the delta and theta activity range. This gives reason to assume an encephalitis. The result of an electrocardiogram reveals a sinus bradycardia. The therapy was symptomatically, virustatically with aciclovir, antibiotically with cefotaxim and prophylactically against edema of brain with dexamethason. After 24 hours the patient abruptly awakes from coma and after 36 hours the reason for the coma can be stated: The toxicological examinations of the blood lead to the result: Intoxication with Baclofen. Explantation for the origin of the tablets: The family lives together with an aunt, who, after a cerebrovascular accident, was treated with Baclofen, Amitryptilin and ASA.

Selected clinical aspects of acute intoxication with baclofen

Baclofen is a lipophilic analogue of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in central nervous system. The aim of the study was to evaluate some clinical aspects of acute intoxication with baclofen. Fifty two patients (37 females and 15 males) aged from 14 to 58 (mean 30.6 +/- 13.7) years were analyzed. Patients were admitted to the Clinic of Internal Diseases and Acute Poisonings Medical University of Gdańsk and the Centre of Acute Poisonings of Praski Hospital in Warszawa during the years 1996-2004 because of suicidal intoxication with baclofen. The doses of baclofen varied from 100 to 1500 (mean 444.8 +/- 317.8) mg. There were twenty eight patients (53.8%) in deep coma (III and IV grade of Matthew scale). Acute respiratory failure which required mechanical ventilation was observed in 18 cases (34.6%). Cardiac abnormalities included bradycardia (36.5%), hypertension (32.7%) and hypotension (3.8%). Toxic psychoses were observed in 6 cases (11.5%). The dosage of baclofen in patients with acute respiratory failure (ARF) was significantly higher than in patients without ARF. Treatment of patients with acute baclofen intoxication should take place in hospitals appropriately equipped which can provide artificial respiration.

Baclofen toxicity in an 8-year-old with an intrathecal baclofen pump

Baclofen delivered by intrathecal pumps (ITB) is increasingly being utilized in the pediatric population, however, resources and education to support problems with these devices are limited. Typical management strategies for systemic baclofen overdose include removal of baclofen from the device reservoir or removal of cerebrospinal fluid from the adjacent device catheter. Appropriate care of these patients requires awareness of the clinical patterns of toxicity and mechanics of the ITB pump delivery system. This report describes the clinical presentation, unfamiliar dilemmas, and the management of a pediatric patient with intrathecal baclofen toxicity, noting problems that may arise in the care of these patients.

[Acute intoxication with baclofen]

Many authors have noticed an increase in suicidal intoxication with baclofen, a lipophilic analog of gamma-aminobutyric acid (GABA). Although morbidity and mortality is low in baclofen overdosage however may cause serious respiratory failure as also cardiac and neurological system disturbances. The aim of the study was to evaluate some clinical aspects of acute intoxication with baclofen. We analyzed 18 patients (8 females and 10 males) aged from 15 to 58 (mean 33+/-15.4) years. Patients were admitted to the Department of Toxicology in the years 1996-2003 because of suicidal intoxication with baclofen. Number of patients intoxicated with baclofen during the last four years of analysis was two times more than in the first four years. The doses of baclofen were from 150 to 1500 (mean 388) mg. There were twelve patients (66%) admitted to the Clinic in deep coma (III and IV grade of Matthew scale) with the hyporeflexia and low muscle tone. Acute respiratory failure which required mechanical ventilation (6 to 96--mean 53.2 hours) was observed in 10 cases (55.5%). Cardiac abnormalities included bradycardia (44.4%), hypertension (33.0%) and hypotension (5.5%). Toxic psychoses were observed in 6 cases (33.3%). Flumazenil administration had no impact on clinical advancement of coma. An increase in creatine kinase activity was observed in 12 patients (66.6%).

CONCLUSIONS

There was no correlation between the dosage of baclofen and the clinical outcome. Baclofen poisoned patients should be admitted to hospitals with adequate medical equipment, especially respirators.

Death due to baclofen and dipyrone ingestion

A fatal suicidal intoxication with unusual drugs is reported. A 56-year-old man was found dead in his house; near by the corpse several empty drugs boxes were found. An autopsy was performed and the biological fluids were submitted to a full toxicological work-up. The analytical results supported the hypothesis of a death due to the acute baclofen (4-amino-3-(p-chlorophenyl)butyric acid) and dipyrone (sodium [N-(1,5-dimethyl-3-oxo-2-phenylpyrazolin-4-yl)-N-methylamino] methanesulfonate) intoxication.

[Toxic effects of baclofen in a patient with chronic renal insufficiency]

In this work the authors reported the case of a 29-year-old woman, who had been dialysed since 1997 in the course of chronic pyelonephritis caused by vesicoureteral reflux. Due to the detrusor vesica urinariay's hypofunction (confirmed by repeated urodynamic studies) the patient was prescribed Baclofen with a dosage of 2 x 10 mg per 24 hours. In the course of Baclofen's therapy, toxic effects of the drug like weakness, nausea, vomiting and fears appeared during the second day of treatment. They had been increasing since the patient's admission to the Dialysis Centre where she had immediately undergone the planned haemodialysis. After the initial increase of the poisoning symptoms including the loss of consciousness, patient's state of health improved after approximately two hours since the haemodialysis had been performed. After five more days in hospital, the patient was discharged in general good condition (two more planned haemodialyses were performed at the time of treatment).

Baclofen overdose in two siblings

Baclofen is a muscle relaxant used in both adults and children with neuromuscular disorders to control spasticity. In children, relatively few cases of overdose have been previously reported. We report two cases of baclofen overdose occurring in two siblings. One sibling with cerebral palsy was being treated with baclofen at the time of overdose. Both cases presented with severe respiratory depression requiring mechanical ventilation. Serum baclofen concentrations from both children were significantly elevated. We also review the published literature on baclofen overdose in children and adolescents. These cases emphasize the importance of warning parents about the potential toxicity of baclofen when prescribing the drug to a family member.

Coma mimicking brain death following baclofen overdose

Baclofen toxicity can be a cause of profound coma with brainstem dysfunction mimicking brain death, and is mainly a clinical diagnosis. Measuring plasma levels is not always possible and may be misleading. Imaging results are usually normal. Electroencephalography may show a pattern of burst suppression. At present no effective specific therapy is available. However, as demonstrated in our case, the prognosis can be good even in severe cases, provided it is recognized early enough, and appropriate supportive measures are instituted.

Baclofen and ethanol ingestion: a case report

The number of reported cases of skeletal muscle relaxant ingestion has been increasing in the United States, although fatalities are rare. A 30-year-old women ingested 300 mg of baclofen and ethanol. She was able to ambulate into the Emergency Department (ED) 50 min later, but within 30 min post-arrival had a Glasgow Coma Score of 3. She was treated with supportive care including mechanical ventilation for 36 h. Her neurologic status returned to her previous state. Coma may occur rapidly after baclofen overdose, and the respiratory depression may be exacerbated by the co-ingestion of ethanol. Primary importance in the treatment of such ingestions should be placed on maintenance of an airway and respiratory support.

Baclofen overdose: drug experimentation in a group of adolescents

BACKGROUND

Baclofen, a lipophilic analog of gamma-aminobutyric acid, is clinically used to control spasticity. We report a mass exposure to baclofen in adolescents seeking intoxication; toxicokinetic data are included.

CASE SERIES

A group of adolescents became symptomatic after ingesting 3 to 30 20-mg tablets of baclofen during a party at a suburban Boys' Club. Several children were noted to be very lethargic by chaperones, ingestion was suspected, and paramedics were called. Some white tablets were found in a couch at the site of the party. The Massachusetts Poison Control Center was called, and the tablets were identified as baclofen (20 mg). Fourteen patients were taken to local hospitals; 9 required intubation. Eight adolescents were transferred to our institution. In these 8 patients, symptoms were noted within 1 to 2 hours after overdose. The most common clinical findings included coma (7), hypothermia (6), bradycardia (5), hypertension (4), and hyporeflexia (8). Mean length of mechanical ventilation was 40 hours. Three patients had unifocal premature ventricular contractions. Two patients had tonic-clonic seizures. A single dose of activated charcoal was given to all patients. Drugs administered included nifedipine (1), flumazenil (1), naloxone (1), lorazepam (2), and phosphenytion (2). All patients recovered and were discharged home within 5 days of ingestion. Serial serum baclofen levels were obtained in all intubated patients (range, 0.049 to 6.0; normal, 0.08 to .40 microgram/mL). Levels obtained 14 hours after ingestion showed a linear correlation with length of mechanical ventilation (R2 = 0.9863). Persistent symptoms were noted in some patients, despite nondetectable baclofen levels. Toxicologic screening for drugs of abuse was negative except in 2 patients with ethanol levels, both < 5 mg/dL.

CONCLUSION

Baclofen overdose may result in coma, apnea, autonomic disturbances, cardiac conduction abnormalities, and seizures. Levels obtained shortly after overdose correlate with length of mechanical ventilation.

Baclofen toxicity in patients with severely impaired renal function

OBJECTIVE

To report the toxic effects of baclofen in patients with severely impaired renal function.

DATA SOURCES

From 1991 to 1995, nine patients with severely impaired renal function (2 not receiving dialysis, 1 undergoing continuous ambulatory peritoneal dialysis [CAPD], and 6 receiving maintenance hemodialysis), who exhibited clinical toxicity after baclofen therapy at our hospital were included for analysis. Another seven cases from the literature obtained by computerized (MEDLINE) and manual (Index Medicus) search methods published between 1980 and 1995 were also reviewed.

INTERVENTION

Among our nine patients, the six undergoing chronic hemodialysis and one not undergoing dialysis received early (< 48 h) hemodialysis after toxic symptoms developed. The patient undergoing CAPD received late hemodialysis (> 72 h), and the other patient who had not undergone dialysis received only supportive care.

RESULTS

A review of these 16 cases revealed that most patients received only small doses and very short-term baclofen therapy. Altered consciousness was the major presenting feature. Severe acute complications, such as seizures and respiratory depression, were relatively uncommon among patients with severely impaired renal function. However, abdominal pain, which has previously rarely been reported, was noted in five of our nine patients. Most patients showed clinical improvement after hemodialysis. An analysis of these nine patients revealed that those who received early hemodialysis had a shorter recovery time than the patient who received only supportive care (2.71 +/- 0.42, respectively, vs. 9 d; p < 0.01). A lag of several hours between the end of the hemodialysis session and an improvement in the level of consciousness was noted.

DISCUSSION

As most patients with severely impaired renal function developed toxic symptoms soon after initiating a low-dose baclofen regimen, the accumulated dosage was small and severe complications were less common. Abdominal pain may have occurred as a result of the gamma-aminobutyric acid-mediated cholinergic effect exerted by baclofen. The delay in conscious recovery after hemodialysis may be due to a delay in the clearance of baclofen from the central nervous system.

CONCLUSIONS

Patients with severely impaired renal function generally develop baclofen intoxication soon after the initiation of low-dose therapy. Thus, the administration of baclofen, regardless of the dosage, in these patients is not appropriate. Abdominal pain, in addition to altered consciousness, is a common presenting feature in patients with renal failure who have baclofen intoxication. Hemodialysis is effective in alleviating the clinical symptoms and shortening the recovery time for such patients.

Flumazenil: an unreliable antagonist in baclofen overdose

We report a case of inadvertent overdose of baclofen given intrathecally resulting in coma. This was unresponsive to flumazenil and required supportive intensive therapy. With the increasing use of baclofen intrathecally for spasticity and its wide interpatient dose variability, there is a need to find a safe antagonist to baclofen for routine medical use.

Baclofen poisoning in children

Six cases of acute baclofen (LIORESAL) overdose in children are reported. Rapid onset of central nervous system depression with respiratory depression was present to a greater or lesser degree in all patients. Agitation, convulsions and ataxia were also seen. The entire cohort responded to supportive management. An accurate assessment of the quantity of drug ingested was not possible. The need for education on safe drug storage and disposal is emphasized.

[Six cases of baclofen poisoning--clinical course and evaluation of conventional treatment and hemodialysis]

6 cases of baclofen overdose were presented. Intentional (suicidal) poisonings of baclofen are rare but their course is serious because of deep coma and cardiodepression. Till now the baclofen poisonings have been treated conventionally. Basing on the pharmacological data (action and kinetics) of baclofen and high severity of poisoning haemodialysis was used in all of them with good effect. The efficacy of such treatment was evaluated and results were compared to the toxicological literature data.

Baclofen toxicity in a patient with subclinical renal insufficiency

Baclofen, a centrally acting gamma-aminobutyric acid agonist is a commonly used pharmacotherapy for spasticity of spinal origin. It is primarily excreted by glomerular filtration with a clearance proportional to creatinine clearance. We describe a 39-year-old quadriplegic women who, over a 16-week period, developed clinical signs of baclofen toxicity confirmed by progressively rising serum baclofen levels while on a conventional stable dosing regimen. During this period blood urea nitrogen and creatinine concentrations were normal and stable (9mg/dL and 0.8mg/dL, respectively). However, creatinine clearance values were consistently low (55 to 60m/min), suggesting renal insufficiency as the underlying cause. After a decrease in baclofen dosage, evidence of baclofen toxicity resolved. Clinicians should be alert to signs of evolving baclofen toxicity even in patients on an apparently stable regimen. Baclofen dosage adjustments based on systemic baclofen level may play a role in optimizing the clinical management of spasticity.

Supraventricular tachyarrhythmia associated with baclofen overdose

Baclofen overdose occasionally results in cardiac effects, but serious tachyarrhythmias have not been reported. We present the case of a 21-year-old man with an acute baclofen overdose who developed increased cardiac conduction times and a rapid supraventricular tachyarrhythmia which required medical intervention. Acute baclofen toxicity can result in the development of tachyarrhythmias and cardiac monitoring is warranted in acute overdose states.

Electrophysiological findings in a case of severe intrathecal baclofen overdose

Multimodality evoked potentials were examined in a case of serious accidental intrathecal baclofen overdose in a patient who suffered from severe spasticity due to a traumatic brain lesion. Electrophysiological findings during, before and after the intoxication were compared. Transcranial electrical stimulation up to 750 V did not evoke any responses in thenar muscles on the first day of intoxication. An improvement to normal values was observed within 3 days, paralleled by an amelioration of the patient's clinical condition. Cervical electrical stimulation was largely unaffected by baclofen. Median nerve somatosensory and brain-stem acoustic evoked potentials revealed few or no differences during intoxication compared to pre- and post-intoxication responses.

[Baclofen intoxication in chronic hemodialysis and kidney transplantation]

Fourteen days after renal transplantation, at first gave with good transplant function, a 36-year-old woman developed neurogenic dysfunction of bladder emptying. This was treated with baclofen, 5 mg three times daily by mouth. Between the 7th and 10th treatment day she progressively developed an organic psychotic syndrome and increasing respiratory paralysis after the onset of renal failure, associated with rejection of the transplanted kidney which required dialysis. Plasma concentration of baclofen was 565 ng/ml (therapeutic range 80-400 ng/ml). After discontinuing the drug and renewed haemodialysis the baclofen level rapidly fell and the symptoms receded. In a second case, a 57-year-old man on dialysis developed a thalamic pain syndrome after an intracerebral haemorrhage in the region of the basal ganglia. He was given four times 10 mg baclofen by mouth over 24 hours. 24 hours after the first dose he became deeply unconscious with respiratory failure. Plasma concentration of baclofen after the first haemodialysis period was 480 ng/ml. After 48 hours of artificial ventilation it was possible to extubate; a symptomatic transitory psychotic syndrome disappeared within 4 days. Both patients had pre-existing cerebral damage in addition to the chronic renal failure (in the first patient, meningoencephalitis 30 years previously with persisting focal lesions in the computed tomogram CT]; in the second one, residual lesions in the CT after intracerebral haemorrhage). It is emphasized that in patients who are in renal failure baclofen treatment should be undertaken cautiously: toxic signs can quickly develop especially if there is pre-existing cerebral damage.

Baclofen intoxication: report of four cases and review of the literature

Four cases of baclofen intoxication are reported, with a review of 33 cases from the literature. Analysis of these 37 cases suggests that there are two types of baclofen intoxication syndrome. Patients with acute intoxication present with four major clinical manifestations: encephalopathy (disturbance of consciousness and/or seizure), respiratory depression, muscular hypotonia, and generalized hyporeflexia. Patients with chronic intoxication present with hallucinosis, impaired memory, catatonia, or acute mania. The acute intoxication syndrome has a faster onset, shorter duration, more severe clinical manifestations, and higher incidence of seizures than the chronic intoxication syndrome. Baclofen intoxication, although it may cause grave encephalopathic manifestations and electroencephalographic findings, has a benign outcome if actively managed.

Complications of intrathecal baclofen delivery

The medical records of 46 consecutive patients who have had intrathecal Baclofen drug delivery systems implanted in the National Spinal Injuries Centre, the Paddocks Hospital Spinal Unit, Princes Risborough, Lodge Moor Hospital Spinal Unit, Sheffield, the Northern Regional Spinal Injuries Unit, Hexham and The Radcliffe Infirmary, Oxford, were reviewed. Patients were contacted to describe their views on the treatment. The complications of the treatment are described. Some, such as overdose and meningitis are particularly hazardous. Others, in particular pump tubing revisions, are more of an inconvenience and time consuming for the patient and physician. If the serious risks of this valuable treatment are to be minimized and the therapy applied most effectively than a well co-ordinated team is essential, involving in particular the physician responsible for the initial assessment and follow-up of the patient and an experienced surgeon. It is recommended that only a small number of centres in the UK undertake these implants.

Toxicological analysis of a fatal baclofen (Lioresal) ingestion

A fatality following ingestion of the drug baclofen (Lioresal) is described. Baclofen was identified in urine by gas chromatography/mass spectrometry. After derivatization with trinitrobenzene sulfonic acid, baclofen was quantitated in serum and urine by high-performance liquid chromatography. The concentration of baclofen was 17 mg/L in serum and 760 mg/L in urine collected approximately 12 h after the overdose. To our knowledge, this is only the second reported fatality involving a baclofen overdose. The previous case did not include quantitation of baclofen in any biological fluid.

Burst suppression EEG with baclofen overdose

The article reports the case history of a patient with baclofen intoxication and burst suppression activity in the EEG several hours after baclofen ingestion. With symptomatic treatment the patient recovered within 5 days and the EEG became normal, again.

[Is absorption hemoperfusion effective in the treatment of baclofen poisoning?]

By six-hour sorption haemoperfusion over active charcoal in a 33-year-old woman intoxicated with baclofen (Baclofen Polfa) the initial plasma concentration was reduced by 87%, while from the blood only 3% of the ingested dose were removed. Therefore the capacity of baclofen elimination was tested by perfusion and dialysis in vitro. Two-hour dialysis with the Czechoslovak haemodialyzer Chiraplat was equally effective for removal of baclofen from an aqueous solution (21.2 mg) as four-hour perfusion over active charcoal and resin--Czechoslovak haemoperfusion columns Hemasorb 800 C (19.4 mg) and Hemasorb 800 A-4 (18.9 mg). Because during the first 30 minutes of perfusion the resin sorbent has a double extraction, as compared with dialysis, it is better to use in serious intoxication haemodialysis and haemoperfusion concurrently.