Baclofen Overdose - Symptoms and Treatment

Introduction

Baclofen is a common skeletal muscle relaxant used to treat the symptoms of muscle spasticity. It relieves muscle spasms, tightness, and crampings due to underlying medical conditions like multiple sclerosis and spine injuries. It is available as a tablet, suspension, and solution. Baclofen overdose occurs due to accidental ingestion of heavy doses or chronic consumption of larger doses to relieve pain and spasms. Therefore, Baclofen doses must be monitored regularly to avoid overdose and toxicity. In addition, Baclofen overdose will result in adverse health effects like gastric irritations, tiredness, respiratory insufficiency, and, in advanced cases, may lead to coma.

What Is Baclofen?

Baclofen is used to treat skeletal muscle stiffness and tightness due to medical conditions like multiple sclerosis and spinal cord injuries. Other uses of Baclofen include the treatment of hiccups and sudden muscle contractions. Chemically, Baclofen is a derivative of gamma-aminobutyric acid (GABA), a neurotransmitter. It reduces the symptoms of muscle rigidity and stiffness by acting on the gamma-aminobutyric acid (GABA) receptors in the brain and spinal cord.

Baclofen is commonly administered as an oral drug (tablets). In cases of severe muscle spasms due to spinal injury, they are given through an intrathecal pump, which delivers the drug directly into the space between the spinal cord and the protective sheath surrounding the spinal cord. Baclofen can be used alone or with other medications to relieve pain, muscle spasms, and rigidity. Baclofen is considered effective and safe for adults and children. Each Baclofen tablet used for oral administration contains 10 to 20 milligrams of Baclofen. Inactive ingredients like magnesium stearate, colloidal silicon dioxide, potato starch, microcrystalline cellulose, and povidone are also present.

What Is the Pathophysiology of Baclofen Overdose?

Baclofen is an agonist of the G-protein-mediated GABA B receptor. These GABA B receptors are present in the brain and spinal cord presynaptically and postsynaptically. Baclofen works in the spinal cord at the therapeutic level. Presynaptically, it binds and decreases calcium influx, impairing neurotransmitters' release. Baclofen causes potassium efflux and cell hyperpolarization at the postsynaptic neuron, producing an inhibitory effect.

What Are the Uses of Baclofen?

• Approved by the Food and Drug Administration (FDA) for the treatment of pain, clonus, reversible spasticity, and flexor spasms, which occur as sequelae of multiple sclerosis and spinal cord lesions.

• Intrathecal (into the spinal canal) administration of Baclofen is used to manage spasticity, which occurs due to spinal cord injury, traumatic brain injury, and being unresponsive to other drugs.

• Baclofen is also used for the management of alcoholic liver disease.

• Baclofen can reduce the symptoms of trigeminal neuralgia, hiccups, and gastrointestinal reflux disease.

• In some cases, Baclofen is used to decrease alcohol cravings for the management of alcohol use disorder.

What Are the Common Side Effects Associated With Baclofen?

Some individuals will develop side effects after using Baclofen. It includes the following:

• Headache.

• Nausea.

• Constipation.

• Weakness.

• Tiredness.

• Increased urination.

• Confusion.

• Altered sleeping patterns.

• Drowsiness.

• Mood changes.

• Hallucinations.

• Itching or tingling sensation in hands and legs.

• Fever.

• Shallow breathing.

What Is the Normal Dosing Regimen for Baclofen?

The average dose of Baclofen needed to relieve the symptoms of muscle rigidity and spam will differ for different patients. It depends on the severity of symptoms, the strength of the medication, and the number of doses the patient takes each day. Therefore, Baclofen doses must be finalized and followed after consulting a doctor's opinion.

1. Oral Dose for Tablets

• Adults: Start the dose at five milligrams three times a day. Doctors may increase the dose gradually to achieve the desired response. The maximum dose will be up to 80 milligrams per day.

• Children: Dose and usage will be determined by a doctor based on the clinical conditions.

2. Oral Dose for Solution

• Adults: Start the dose of five milliliters three times a day. Based on the patient's need, the dose can be increased.

3. Intrathecal Administration: Patients initially receive a single dose of 50 micrograms of Baclofen and are observed for four to eight hours. This dose is known as a screening dose. After obtaining a positive response to the screening dose, the dose will be doubled and observed. Daily dose adjustments are made based on the patient's response and the relief of symptoms. For most patients, the original maintenance dose of Baclofen is gradually increased to obtain a good response.

What Is Baclofen Toxicity?

Baclofen overdose primarily occurs due to accidental ingestion of Baclofen tablets or errors during intrathecal administration. Acute Baclofen toxicity may occur in patients receiving intrathecal Baclofen (ITB) pump delivery systems. During intrathecal Baclofen (ITB) administration, the administered values must be monitored regularly to avoid overdose and toxicity. Renal impairment is a major risk factor for Baclofen toxicity. Baclofen is majorly excreted through the kidney. Proper patient history, vitals examination, and diagnosis must be made before starting intrathecal Baclofen.

What Are the Symptoms of Baclofen Toxicity?

Common symptoms associated with Baclofen toxicity include vomiting, gastric disturbances, confusion, nausea, autonomic dysfunction, hypotonia (weak muscles), muscle jerks, drowsiness, and seizures. Adverse health effects associated with Baclofen toxicity include the following.

• Hypotension.

• Delirium.

• Seizures.

• Breathing difficulties.

• Cardiac abnormalities.

• Flaccid paralysis. (neurological condition characterized by weakness or paralysis)

• Hypothermia. (significant and potentially dangerous drop in body temperature)

• Agitations.

• Hyperreflexia. (Skeletal muscles have increased or overactive reflex response)

• Impaired memory.

• Lethargy.

• Mania.

• Tremors.

• Respiratory failure.

• Encephalopathy. (Disorder of brain)

• Coma.

What Are the Treatment Options for Baclofen Toxicity?

• There are no definite treatment options for Baclofen toxicity.

• Effective management involves cessation of Baclofen administration and supportive management to establish proper respiratory and circulatory function.

• Acute intrathecal Baclofen overdose is managed with cessation of Baclofen and cerebrospinal fluid aspiration to reduce Baclofen load.

• In case of acute toxicity due to the consumption of oral Baclofen, gastric decontamination can be performed to remove the ingested tablets from the stomach before the development of toxicity. Activated charcoal and gastric lavage can remove toxic substances from the gastrointestinal system before absorption.

• Intravenous fluids can be given to the patient to manage hypotension.

• In case of respiratory depression, endotracheal intubation can be done.

• Seizures associated with Baclofen toxicity can be managed by using benzodiazepines.

• Hemodialysis is recommended in patients with renal diseases and insufficiency. It helps decrease plasma levels of Baclofen in individuals with altered renal function.

What Is the Prognosis of Baclofen Toxicity?

There will be good outcomes for patients if they are stabilized early in their toxicity. The patient’s mental status will improve when the serum concentration of Baclofen decreases. Massive Baclofen overdoses of up to 1 to 2 grams may be fatal.

Conclusion

Baclofen is commonly used to treat muscle spasticity. It is safe in proper doses, with fewer side effects in certain individuals. Baclofen toxicity will occur due to abnormal drug levels in the body and the resultant adverse health effects. Proper dosage must be followed as per a doctor's instructions to avoid toxicity and dangerous health effects. Care must be taken during intrathecal administration of Baclofen (ITB) to avoid human errors and toxicity.