Neurological evolution of severe baclofen intoxication: from brain death mimic to recovered brain function.

Patients with brain death have by definition irreversible and complete loss of brainstem reflexes. Before a definite diagnosis of brain death can be confirmed, all potential confounders must be thoroughly excluded. Baclofen intoxication is a rare cause of brain death mimic characterised by transient deep coma and absence of brainstem reflexes and might be mistaken with brain death. We report the case of a female patient in her 70s who ingested baclofen with suicidal intent and was admitted with a deep coma and loss of all brainstem reflexes and a spontaneous burst-suppression pattern in the electroencephalography which resolved over 10 hours. After a state mimicking brain death for 6 hours, the patient experienced complete recovery. Severe baclofen intoxication can mimic brain death clinically and is associated with temporary pathological electroencephalographic findings. Awareness of this toxidrome is crucial, as appropriate management can lead to full recovery.

Motor-evoked potentials after focal electrical stimulation predict drug-induced convulsion potentials in rats.

Drug-induced convulsions-often caused by the inhibition of GABA receptors and stimulation of glutamate receptors-are difficult to predict in animals. In this study, we attempted to detect the proconvulsant potential using motor-evoked potentials (MEPs) after focal electrical stimulation or upon using a functional observational battery (FOB). Pentylenetetrazole, kainic acid, and pilocarpine were used as convulsion-inducing drugs, and baclofen was used as a negative control. First, each compound was administered to male rats, and the FOB tests were performed. All drugs induced behavioral changes, but no commonality was found. Single electrical stimulation train MEPs were recorded under anesthesia for 60 min (at 5 min intervals) after administration of each drug. A dose-dependent increase in MEPs was observed for each convulsion-inducing drug. Moreover, paired electrical stimulation (conditioned and test) of the cerebral motor cortex was conducted with a 1-15 ms interstimulus interval (ISI), 10 min after administration of the drug. All convulsion-inducing drugs inhibited the short-interval intracortical inhibition (ISI: 3 ms), which may be associated with GABA. Intracortical facilitation (ISI: 11 ms), related to glutamate, was not enhanced by any drug but was inhibited by pilocarpine. Dose correlation was not found in short-interval intracortical inhibition or intracortical facilitation in any drugs. No changes in MEPs were observed after baclofen administration. These results suggest that it is possible to evaluate the convulsion potential and associated mechanisms using MEP, independent of the behavioral changes. The early identification of convulsion potential using this model will lead to more efficient drug development.

GABAB R activation partially normalizes acute NMDAR hypofunction oscillatory abnormalities but fails to rescue sensory processing deficits.

Cognitive deficits and impaired sensory processing are hallmarks of several neurodevelopmental and neuropsychiatric disorders. N-methyl-d-aspartate receptor (NMDAR) hypofunction contributes to these deficits by disrupting the excitation-to-inhibition balance in neuronal networks. Although preclinical data suggest that the activation of gamma-Aminobutyric acid B receptors (GABAB R) may restore excitation-to-inhibition balance and rescues some behavioral deficits, GABAB R agonists have failed to meet their clinical study endpoints, suggesting more complex interactions at play. Here, we studied the effects of Baclofen (a GABAB R agonist) and MK-801 (a non-competitive NMDAR antagonist) on the neurophysiology of limbic-auditory circuits in freely-moving rats. The pharmacological effects were assessed using resting-state EEG, auditory-evoked oscillation, and mismatch negativity paradigms. MK-801 elevated resting-state oscillatory power, mainly in the gamma and higher frequency ranges, and impaired auditory-evoked responses. Baclofen partially normalized resting-state oscillations but failed to rescue auditory-evoked oscillatory abnormalities. Coherence analysis indicated that NMDAR hypofunction alters the functional coupling of limbic and thalamocortical circuits in several frequency bands. Baclofen normalized only a fraction of MK-801-induced abnormalities (e.g., theta coherence between frontal cortex and amygdala) while reducing delta-theta and augmenting gamma coherence in thalamocortical circuits. Finally, we report that Baclofen intensified the MK-801-induced deficits in auditory mismatch responses. In summary, while Baclofen partially normalizes MK-801-induced gamma abnormalities, it either fails to rescue or exacerbates deficits in other phenotypes like functional coupling and auditory processing. We hope that the presented complex interactions between pharmacologically induced NMDAR hypofunction and GABABR agonism inspire a new understanding of the therapeutic potential around GABAergic modulation.

Carcinogenicity Evaluation of Baclofen in TgrasH2 Mice.

Baclofen is a γ-aminobutyric acid-B receptor agonist used for control of spastic muscle activity and as a treatment for alcohol abuse. The review of the nonclinical database suggested a data gap for potential carcinogenicity following long-term use. Regulatory requirements for pharmaceutical safety testing of cancer-causing potential have historically included 2-year rodent studies in rats and mice. The availability of transgenic models with greater specificity and sensitivity to carcinogens provides safety testing alternatives that align with the 3Rs. The carcinogenicity of baclofen was evaluated in CB6F1-TgrasH2 transgenic mice following daily oral administration at 45, 90, and 180 mg/kg/d for 26 weeks, preceded by a 2-week drug-conditioning period. There were no treatment-related palpable masses or neoplastic findings, and survival rates were not affected by the baclofen treatment. In conclusion, baclofen was considered as noncarcinogenic in CB6F1-TgrasH2 mice, which is consistent with results previously obtained in a 2-year rat study.

Removal of baclofen with hemodialysis is negligible compared to intact kidney excretion in a pediatric overdose: a case report.

INTRODUCTION: Severe baclofen toxicity can result in respiratory failure, hemodynamic instability, bradycardia, hypothermia, seizures, coma, and death. While hemodialysis (HD) is well-described in treating acute baclofen toxicity in patients with end-stage kidney disease or acute kidney injury, the utility of HD for patients with normal kidney function is uncertain. Implementing HD to speed recovery after a large acute baclofen ingestion is appealing, considering: (a) potential for prolonged coma and ventilator-associated morbidity, and (b) baclofen's low protein-binding, low molecular-weight, and moderate volume of distribution. METHODS: We report a 51 kg, 14-year-old girl who presented to the emergency department (ED) with hypotension, obtundation, and status epilepticus after an intentional ingestion of 1200 mg baclofen. Her post-intubation neurologic examination was concerning for coma. A 14-hour post-ingestion baclofen concentration was 882 ng/mL (therapeutic range 80-400 ng/mL). Three urgent-HD sessions were performed to reduce her time on the ventilator. RESULTS: The total baclofen removed in the first three-hour HD session was 3.05 mg. The total urinary elimination of baclofen 42 mg over 24-hours on day one. She was discharged without neurologic deficits to psychiatry on day-14. CONCLUSION: In this case, the amount of baclofen recovered during HD is negligible in comparison to the amount cleared by kidney elimination in this patient with normal kidney function.

Prevalence and risk factors of baclofen neurotoxicity in patients with severely impaired renal function / Prevalencia y factores de riesgo de la neurotoxicidad por baclofeno en pacientes con la función renal gravemente deteriorada

BACKGROUND/AIMS: The most common adverse effect of baclofen, used for managing hiccups and spasticity, is neurotoxicity. As baclofen is primarily excreted by the kidneys, neurotoxicity is more likely to occur in patients with chronic kidney disease (CKD). We evaluated the risk factor for baclofen neurotoxicity and the recommended dosage for patients with severe CKD. METHODS: In this single-center retrospective study, we classified 401 patients with CKD as stage 4 (n=174), non-dialysis stage 5 (n=97), and on-dialysis (n=130). RESULTS: The prevalence of baclofen-induced neurotoxicity in patients with severe CKD was 7.0% (28 of 401 patients). There was no significant difference in the presence of neurotoxicity when the patients were classified as CKD stage 4, stage 5, and dialysis patients. There were significant differences in serum albumin levels and the presence of diabetic nephropathy between the patients with neurotoxicity and those without. The results from a multiple logistic regression analysis showed that serum albumin was independently associated with baclofen neurotoxicity (p = 0.007). The minimum daily dose for baclofen neurotoxicity was 10mg, 10mg, and 5mg in patients with CKD stages 4 and 5, and dialysis, respectively. CONCLUSIONS: In this study, the prevalence of baclofen-induced neurotoxicity in patients with severe CKD was 7.0%. Serum albumin was identified as an independent risk factor for neurotoxicity. We recommend initially administering a daily dose of 7.5mg for patients with severe CKD stages 4 and 5, and a daily dose of 2.5mg for patients receiving dialysis

ANTECEDENTES/OBJETIVOS: La neurotoxicidad es el efecto adverso más frecuente del baclofeno, un fármaco que se utiliza para tratar los espasmos y la espasticidad. Dado que el baclofeno se excreta principalmente a través de los riñones, es más probable que la neurotoxicidad se presente en pacientes con enfermedad renal crónica (ERC). Hemos evaluado el factor de riesgo para la neurotoxicidad por baclofeno y la dosis recomendada para pacientes con ERC grave. MÉTODOS: En este estudio retrospectivo unicéntrico, se clasificó a 401 pacientes con ERC en estadio 4 (n=174), estadio 5 sin diálisis (n=97) y en diálisis (n=130). RESULTADOS: La prevalencia de la neurotoxicidad inducida por baclofeno en pacientes con ERC grave fue del 7,0% (28 de 401 pacientes). No se observaron diferencias significativas en la presencia de neurotoxicidad al clasificar a los pacientes en ERC en estadio 4, estadio 5 y pacientes en diálisis. Se observaron diferencias significativas en los niveles de albúmina sérica y en la presencia de nefropatía diabética entre los pacientes con y sin neurotoxicidad. Los resultados de un análisis de regresión logística múltiple mostraron que la albúmina sérica estaba asociada de manera independiente a la neurotoxicidad por baclofeno (p = 0,007). La dosis diaria mínima para la neurotoxicidad por baclofeno fue de 10, 10 y 5mg en pacientes con ERC en estadio 4, estadio 5 y en diálisis, respectivamente. CONCLUSIONES: En este estudio, la prevalencia de la neurotoxicidad inducida por baclofeno en pacientes con ERC grave fue del 7,0%. Se identificó la albúmina sérica como un factor de riesgo independiente de neurotoxicidad. Recomendamos una administración inicial a una dosis diaria de 7,5mg en pacientes con ERC grave en estadios 4 y 5, y una dosis diaria de 2,5mg en pacientes que reciben diálisis

Design, characterization and in vivo evaluation of modified release baclofen floating coated beads.

Baclofen is a centrally acting skeletal muscle relaxant approved by the US Food and Drug Administration (FDA) for the treatment of muscle spasticity, but the immediate release mode of administration and rapid absorption has been associated with adverse effects. The main objective of this study was to prepare modified release floating beads of baclofen in order to decrease the unwanted side effects. The beads were prepared using alginate and coated with Eudragit RS100, Eudragit L100 and cetyl alcohol. They were evaluated for their encapsulation efficiency, buoyance characteristics, morphology, and in vitro release. They have also been tested in vivo for their oral bioavailability and potential side effects. The prepared beads showed floating properties up to 12 h with different lag times ranging from 45.67 to 72.33 sec. Morphological evaluation using scanning electron microscopy (SEM) revealed that the coated beads show smooth with no pores or cracks surfaces. Real-time morphology of the beads during in vitro release testing was studied by the SEM. Optimized formulation of baclofen coated beads exhibited favorable mechanical properties, in addition, it provided extended baclofen release for up to 6 h. In addition, in vivo studies showed that the coated beads effectively decreased the hypotensive side effect associated with rapid plasma peaking from Baclofen® immediate-release tablets. In addition, there were significant differences between the values of Cmax, Tmax, and AUC0-24 of optimized modified release baclofen floating formulations when compared to Baclofen® immediate-release tablets.

An intoxication mimicking brain death: baclofen.

Baclofen is a derivative of gamma-aminobutyric acid, used mainly for the treatment of muscle spasticity. Baclofen overdose can result in severe respiratory depression, autonomic disturbances, seizures and coma. Here we report a 15-year-old girl who was found unresponsive, intubated and admitted to the PICU. On initial presentation, her Glasgow Coma Score was 3, with fixed dilated pupils. EEG revealed cerebral bioelectric activity and ground amplitudes significantly lower than normal. Supportive treatments were administered. On the 2nd PICU day, she regained consciousness and was able to follow commands. She was extubated and discharged on hospital day 3. Conclusively emergency physicians should consider baclofen overdose in children presenting with acute loss of consciousness, flaccidity, and hyporeflexia.

Single-dose baclofen-induced neurotoxicity in a patient with end stage renal disease: case report.

BACKGROUND: Baclofen is a centrally acting GABAB receptor agonist and it is used widely for the treatment of spasticity, persistent hiccups and multiple sclerosis. The renal system is the main route of excretion, thus people with suboptimal renal function are prone to baclofen intoxication. Multiple doses of baclofen have been associated with toxicity, but it is very unusual that single dose can do so. CASE PRESENTATION: A 47 year old female patient with end stage renal disease (ESRD) presented with a sudden onset of altered mental status and state of unconsciousness after the ingestion of one tablet of baclofen 25 mg. All other possible causes were ruled out and a diagnosis of baclofen toxicity was considered. The patient showed dramatic improvement after an extra two sessions of hemodialysis. CONCLUSIONS: We highly recommend that more educational efforts are made for health care professionals about the possible risk of baclofen toxicity among kidney-impaired patients. We also recommend avoiding baclofen use if evidence of chronic renal disease is present and to seek other alternatives for pain management.

Baclofen-Induced Neuro-Respiratory Toxicity in the Rat: Contribution of Tolerance and Characterization of Withdrawal Syndrome.

Baclofen, a γ-amino-butyric acid type-B receptor agonist with exponentially increased use at high-dose to facilitate abstinence in chronic alcoholics, is responsible for increasing poisonings. Tolerance and withdrawal syndromes have been reported during prolonged treatment but their contribution to the variability of baclofen-induced neurotoxicity in overdose is unknown. We studied baclofen-induced effects on rat sedation, temperature, and ventilation and modeled baclofen pharmacokinetics and effect/concentration relationships aiming to investigate the consequences of repeated baclofen pretreatment and to characterize withdrawal syndrome. Baclofen-induced dose-dependent sedation (p <0.01), hypothermia (p <.001) and respiratory depression (p <.01) were altered in repeatedly baclofen-pretreated rats (p <.05). Repeatedly baclofen-pretreated rats did not exhibit respiratory depression following baclofen overdose due to limitations on baclofen-induced increase in inspiratory (p <.01) and expiratory times (p <.01). Only slight hypoxemia without respiratory acidosis was observed. Baclofen discontinuation resulted in hyperlocomotion and non-anxiogenic withdrawal symptoms. Regarding pharmacokinetics, repeated baclofen pretreatment increased the peak concentration (p <.05) and absorption constant rate (p <.05) and reduced the distribution volume (p <.0001) and elimination half-life (p <.05). Analysis of the effect/concentration relationships indicated that plasma baclofen concentration decreases more rapidly than all studied neuro-respiratory effects, in tolerant and non-tolerant rats. Taken together, our findings supported the role of brain distribution in baclofen-induced neurotoxicity expression and its probable involvement in tolerance-related attenuation in addition to physiological adaptations of ventilation. In conclusion, repeated pretreatment attenuates baclofen-attributed neurotoxicity in overdose and results in post-discontinuation withdrawal syndrome. Our findings suggest both pharmacodynamic and pharmacokinetic mechanisms whose relative contributions to the variability of baclofen-induced neurotoxicity in overdose remain to be established.

Baclofen systemic toxicity: Experimental histopathological and biochemical study.

OBJECTIVE: The present study was designed to highlight the toxic impact of baclofen on both biochemical and histopathological aspects in rats' liver, gastric, lung, kidney, and brain tissues. METHODS: The study was performed on 30 healthy adult male albino rats divided into four groups with 5 rats in each control group, and 10 rats in either experimental groups (two experimental and two control groups). Five rats (negative control) were kept in a quite non-stressful environment, provided with food ad libitum and free access to water. Normal saline (1 ml) was given orally as placebo in the positive control group ( n = 5). Experimental group III, baclofen acute toxicity group (10 rats): Each animal received a single dose of lethal dose (LD50) of baclofen orally by gavage. It equals 145 mg/kg body weight. The rats were observed for acute toxicity manifestations as well as for LD50 deaths. Group IV, (baclofen-dependent group, 10 rats): Each animal received baclofen (1/10th LD50) in gradually increasing doses for 1 month. RESULTS: The levels of blood urea nitrogen, creatinine kinase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, cardiac troponin I, and prothrombin time in both baclofen-treated groups showed significant elevation when compared to controls. There were brain, lung, gastric, hepatic, and renal histopathological changes in baclofen-treated rats whose severity varied between the two experimental groups. CONCLUSION AND RECOMMENDATION: Baclofen toxicity is an under diagnosed emergency. Physicians should consider baclofen toxicity in users having hepatorenal dysfunction, presenting with altered mental status, bradycardia, and hypotension.

Baclofen Toxicity in a Patient with Hemodialysis-Dependent End-Stage Renal Disease.

BACKGROUND: Oral baclofen toxicity is extremely rare, but can affect patients with renal disease due to the drug's predominant renal clearance of approximately 69-85%. Patients with severely impaired renal function typically develop symptoms soon after initiating baclofen therapy, even at relatively low doses. CASE REPORT: A 69-year-old woman with a history of hemodialysis-dependent end-stage renal disease presented to the Emergency Department with encephalopathy, ataxia, and dystonia after the addition of a recent baclofen prescription for back pain (10 mg twice daily). She had been taking baclofen as prescribed for approximately 1 week when, the day prior to admission, she had increased her dose to a total of 40 mg. Diagnostic studies demonstrated the patient had chronic, end-stage renal disease and a supratherapeutic concentration of baclofen. Signs and symptoms resolved with hemodialysis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is of critical importance for emergency physicians to appreciate impaired baclofen clearance in those with underlying renal disease to obviate the potential for significant drug toxicity.

Baclofen Toxicity Causing Acute, Reversible Dyskinesia.

The following unique case demonstrates an episode of acute dyskinesia secondary to oral baclofen toxicity. We discuss an 80-year-old man with a history of Stage III chronic kidney disease, coronary artery disease, diabetes and stroke who presented to the Emergency Department with new onset of behavioral changes and irregular jerking movements. The patient had been recently prescribed baclofen 10mg twice daily for a back strain he suffered; he subsequently was admitted to the hospital, and his symptoms resolved within 48 hours of admission and discontinuance of baclofen.

Baclofen and pregnancy: birth defects and withdrawal symptoms.

A comparison of 134 pregnant women who had taken baclofen in early pregnancy and 400 pregnant controls showed an increased risk of major malformations. Several infants exposed to baclofen until birth exhibited withdrawal symptoms.

Pharmacological inactivation of the prelimbic cortex emulates compulsive reward seeking in rats.

Drug addiction is a chronic, relapsing brain disorder characterized by compulsive drug use. Contemporary addiction theories state that loss of control over drug use is mediated by a combination of several processes, including a transition from goal-directed to habitual forms of drug seeking and taking, and a breakdown of the prefrontally-mediated cognitive control over drug intake. In recent years, substantial progress has been made in the modelling of loss of control over drug use in animal models, but the neural substrates of compulsive drug use remain largely unknown. On the basis of their involvement in goal-directed behaviour, value-based decision making, impulse control and drug seeking behaviour, we identified the prelimbic cortex (PrL) and orbitofrontal cortex (OFC) as candidate regions to be involved in compulsive drug seeking. Using a conditioned suppression model, we have previously shown that prolonged cocaine self-administration reduces the ability of a conditioned aversive stimulus to reduce drug seeking, which may reflect the unflagging pursuit of drugs in human addicts. Therefore, we tested the hypothesis that dysfunction of the PrL and OFC underlies loss of control over drug seeking behaviour, apparent as reduced conditioned suppression. Pharmacological inactivation of the PrL, using the GABA receptor agonists baclofen and muscimol, reduced conditioned suppression of cocaine and sucrose seeking in animals with limited self-administration experience. Inactivation of the OFC did not influence conditioned suppression, however. These data indicate that reduced neural activity in the PrL promotes persistent seeking behaviour, which may underlie compulsive aspects of drug use in addiction.

Postnatal alterations in GABAB receptor tone produce sensorimotor gating deficits and protein level differences in adulthood.

The GABA transmitter system plays a vital role in modulating synaptic formation and activity during development. The GABAB receptor subtype in particular has been implicated in cell migration, promotion of neuronal differentiation, neurite outgrowth, and synapse formation but it's role in development is not well characterized. In order to investigate the effects of brief alterations in GABAB signaling in development, we administered to rats the GABAB agonist baclofen (2.0mg/kg) or antagonist phaclofen (0.3mg/kg) on postnatal days 7, 9, and 12, and evaluated sensorimotor gating in adulthood. We also examined tissue for changes in multiple proteins associated with GABAB receptor function and proteins associated with synapse formation. Our data indicate that early postnatal alterations to GABAB receptor-mediated signaling produced sex differences in sensorimotor gating in adulthood. Additionally, we found differences in GABAB receptor subunits and kalirin protein levels in the brain versus saline treated controls. Our data demonstrate that a subtle alteration in GABAB receptor function in early postnatal life induces changes that persist into adulthood.

Acute onset rhythmic hiccup-like respirations secondary to oral baclofen toxicity.

OBJECTIVE: Baclofen toxicity has been associated with seizures, coma, apnea, autonomic disturbances, and cardiac conduction abnormalities. It has not been associated with rhythmic hiccup-like respirations. METHOD: We report a patient with suspected baclofen toxicity. RESULTS: Our patient is a 19-year-old girl with cerebral palsy secondary to prematurity and repaired tetralogy of Fallot who had started oral baclofen 8 months before to diminish spasticity. Her main concern was the acute onset of rhythmic, deep, continual, hiccup-like breaths every few seconds, increasing in frequency with exhaustion, and disappearing in sleep. The night after her evaluation, her symptoms significantly worsened. She presented at the Johns Hopkins pediatric emergency room where her symptoms were only somewhat responsive to a benzodiazepine; she was discharged without a clear etiology. After discussion the next day, her baclofen dose was reduced. Within 12 hours, her abnormal respirations disappeared without recurrence. CONCLUSIONS: Respiration involves glutamatergic excitatory synaptic input to medullary inspiratory γ-aminobutyric acid-mediated pacemaker neurons. Baclofen acts on presynaptic γ-aminobutyric acid B receptors on glutamate axons; derangement of this system may explain the irregular respirations in our patient in a dose-dependent fashion.

Activation but not blockade of GABAB receptors during early-life alters anxiety in adulthood in BALB/c mice.

Although the underlying pathophysiology of anxiety disorders is unknown it is clear that a combination of genetic and environmental factors in early life predispose to disease risk. Preclinical research increasingly suggests an important role for the GABAB receptor in modulating anxiety behaviour, with GABAB receptor deficient mice having increased anxiety behaviour. Previous studies have highlighted critical windows during development where adult anxiety behaviour is primed. However, little is known regarding the role played by the GABAB receptors in the developmental processes that underlie adult anxiety behaviour. To this end, we treated male BALB/c mouse pups with the either the selective GABAB receptor agonist, R-baclofen (2 mg/kg, s.c), the GABAB receptor antagonist CGP 52432 (10 mg/kg and 30 mg/kg) or vehicle from postnatal days (P) 14-28. The anxiety behaviour of these mice was then assessed in adulthood (P62 onwards) in a battery of behavioural tests comprising; the stress induced hyperthermia (SIH) test, defensive marble burying (DMB), elevated-plus maze (EPM) and the forced swim test (FST). Postnatal R-baclofen treatment resulted in increased anxiety-like behaviour in the EPM as shown by approach-avoidance and ethological measures. Other behavioural measures were not significantly altered. Interestingly, blockade of GABAB receptors with CGP52432 in early life caused no alterations in emotional behaviour. These data suggest that during early life GABAB receptor signalling can play a functional role in programing anxiety behaviour in adulthood. The underlying neurodevelopmental processes underlying these effects remain to be discovered.

Baclofen toxicity in patients with advanced nephropathy: proposal for new labeling.

BACKGROUND: Despite several reports in the literature of baclofen toxicity in patients with renal dysfunction, the drug is being used for many patients. METHODS: Herein we report a case of baclofen-induced encephalopathy in a patient with pre-end-stage renal disease and review the literature regarding the magnitude of baclofen toxicity in patients with renal insufficiency. A Medline search for studies in English was performed. Twenty-one case reports involving 41 patients (including our patient) were identified. RESULTS: The majority of patients were elderly (62.5% above 60 years) males (56.3%) on dialysis (62.9%). Neurotoxicities were almost always present at presentation. Manifestations of baclofen toxicity usually started 2-3 days after starting baclofen; however, periods as long as 16 weeks have been reported. The daily dose of baclofen ranged from 5 to 60 mg with a mean dose of 20 mg. Hemodialysis (HD) was the most common treatment modality used for drug elimination (65.7%). The recovery time ranged from 2 h in patients who received HD, to 8 days with conservative treatment. CONCLUSION: The literature does not mention a clear recommendation about baclofen safety and dose adjustment, or a minimum level of kidney function below which the drug should not be used.