From the Guidelines
Oral baclofen overdose is a life-threatening condition that requires immediate medical attention, as it can cause severe central nervous system depression, respiratory failure, and even death. The effects of an oral baclofen overdose can be severe and include symptoms such as severe drowsiness, confusion, respiratory depression, seizures, coma, and cardiovascular instability 1. It is essential to note that baclofen is a GABA-B receptor agonist that can cross the blood-brain barrier, leading to central nervous system depression.
Key Considerations
- The severity of overdose depends on the amount ingested, with doses above 200 mg potentially causing serious toxicity.
- Treatment typically involves supportive care, including airway management, ventilatory support if needed, and cardiovascular monitoring.
- Healthcare providers may administer activated charcoal if the ingestion was recent (within 1-2 hours).
- In severe cases, hemodialysis may be used to remove baclofen from the bloodstream.
- Recovery typically occurs within 24-72 hours with proper medical management, though prolonged symptoms may occur in patients with kidney impairment since baclofen is primarily excreted by the kidneys.
Clinical Implications
- Abrupt withdrawal of baclofen in patients who take it long-term can lead to significant withdrawal symptoms, including visual and auditory hallucinations, anxiety, agitation, delirium, fever, tremors, tachycardia, and seizures 1.
- Perioperative management of patients receiving intrathecal baclofen should be planned with input from a specialist in this area to avoid life-threatening complications.
- It is crucial to prioritize immediate medical attention and proper management to prevent long-term consequences and reduce morbidity and mortality associated with oral baclofen overdose.
From the FDA Drug Label
ADVERSE REACTIONS ... Others reported: Neuropsychiatric: ... euphoria, excitement, depression, hallucinations, ... epileptic seizure ... The following laboratory tests have been found to be abnormal in a few patients receiving baclofen: increased SGOT, elevated alkaline phosphase, and elevation of blood sugar.
The effects of an oral Baclofen overdose are not explicitly stated in the drug label. However, based on the reported adverse reactions, it can be inferred that an overdose may exacerbate these effects, potentially leading to:
- Neuropsychiatric symptoms such as confusion, euphoria, excitement, depression, hallucinations, and seizures
- Cardiovascular effects like hypotension
- Gastrointestinal symptoms such as nausea and vomiting
- Abnormal laboratory tests, including elevated liver enzymes and blood sugar levels It is essential to note that these effects are based on reported adverse reactions and may not be directly related to an overdose. The actual effects of an oral Baclofen overdose may be more severe or different from those listed. 2
From the Research
Effects of Oral Baclofen Overdose
- The effects of an oral baclofen overdose can be severe and include coma, respiratory depression, hyporeflexia, and flaccidity 3, 4, 5
- Other symptoms that may occur after an oral baclofen overdose include:
- Baclofen overdose can also lead to a metabolic encephalopathy, characterized by an acute confusional state, generalized slowing on EEG, and triphasic waves 7
- Patients with baclofen neurotoxicity may be susceptible to exacerbation by benzodiazepine therapy, which can cause a marked depression of consciousness and respiration 7
Treatment and Management
- Treatment of oral baclofen overdose typically involves supportive care, including intravenous fluids, atropine, dopamine, and hemodialysis 3
- Activated charcoal may also be administered to help reduce absorption of the drug 4
- In cases of severe overdose, patients may require intubation and mechanical ventilation 4
- Cessation of baclofen and supportive care are the mainstays of management for baclofen neurotoxicity 7