Heart conduction problems in a tetraplegic patient caused by a single therapeutic dosage of Baclofen

• Published in: Spinal cord Vol. 46; no. 4; pp. 317 - 318
• Main Authors: Smit, C A J, Slim, E J
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-04-2008; Nature Publishing; Nature Publishing Group
• Subjects: Adult; Anatomy; Baclofen - administration & dosage; Baclofen - adverse effects; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Bradycardia - chemically induced; case-report; Cerebrospinal fluid. Meninges. Spinal cord; Cervical Vertebrae; GABA Agonists - administration & dosage; GABA Agonists - adverse effects; Heart Conduction System - drug effects; Human Physiology; Humans; Male; Medical sciences; Multiple sclerosis and variants. Guillain barré syndrome and other inflammatory polyneuropathies. Leukoencephalitis; Muscle Spasticity - drug therapy; Muscle Spasticity - etiology; Nervous system (semeiology, syndromes); Neurochemistry; Neurology; Neuropsychology; Neurosciences; Quadriplegia - complications; Quadriplegia - drug therapy; Spinal Cord Injuries - complications; Spinal Cord Injuries - drug therapy; spinal cord injury; heart condition problems; Baclofen; Human; Conduction; Nervous system diseases; Treatment; Vertebral canal; Spinal cord trauma; Central nervous system disease; Spinal cord disease
• ISSN: 1362-4393; 1476-5624
• DOI: 10.1038/sj.sc.3102123

Study design:
Case report.
Objective:
To examine the unusual and unknown, severe side effect of a therapeutic dose of oral Baclofen on cardiac function.
Setting:
Spinal Cord Unit, Rehabilitation Centre Amsterdam, Amsterdam, The Netherlands.
Methods:
Review of relevant literature.
Results:
A 53-year-old patient with an incomplete C2 tetrapareses (ASIA B) developed severe and painful muscle spasms together with respiratory failure and autonomic dysreflexia. Spasmolytic treatment was started. After the first admission of 5 mg of oral Baclofen, he collapsed in bed with extreme bradycardia, hypotension, hyperventilation and decreased oxygen saturation. A second dosage of 5 mg Baclofen resulted in the same complications. After implantation of a pacemaker, restarting oral Baclofen induced a pacemaker rhythm with episode of hypotension and respiratory failure and also a delirium. Intrathecal Baclofen also resulted in a pacemaker rhythm with hypotension and a decreased cardiac output. To our knowledge, this is the first time a severe heart conduction problem was induced in a spinal cord injury patient after a single therapeutic dose of Baclofen.
Conclusion:
In this case therapeutic oral Baclofen has caused serious cardiac conduction problems.