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

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.