Baclofen-induced Coma and Respiratory Depression in a Patient with Cervical Spondylotic Myelopathy with Chronic Kidney Disease

Thotalampatti Pachiyappan Jeyaselvasenthilkumar, Deiveegan Kunjithapatham, Sekar Chinnasamy, Mohamed Abith Ali 
 Department of Neurosurgery, SRM Medical College Hospital and Research Centre, Kattankulathur, Kanchipuram, Tamil Nadu, India

Correspondence Address:
Prof. Deiveegan Kunjithapatham
Department of Neurosurgery, SRM Medical College Hospital and Research Centre, Kattankulathur, Kanchipuram - 603 203, Tamil Nadu
India

Full Text



Sir,

Baclofen is primarily used in spinal cord disorders to limit spasticity. It induces inhibition at the presynaptic motor neuron leading to an anti-spastic response. Oral baclofen toxicity is extremely rare but can affect patients with impaired renal clearance even in very low doses.[1] The symptoms can vary from mild symptoms, such as ataxia or dystonia, to coma and respiratory depression [2] in patients with severely impaired renal function. Hemodialysis rapidly reverses these side effects.

A 64-year-old man from an endemic area of fluorosis presented with features of Cervical spondylotic Myelopathy He was started on oral baclofen 10 mg twice daily. There was no past history of any renal disease. His other medications were tablet acetaminophen and multivitamins. His investigations revealed that he was suffering from fluorosis with ossified posterior longitudinal ligament with extensive calcification of soft tissues of the neck [Figure 1] and [Figure 2]. Ultrasonogram abdomen suggested features of chronic medical renal disease. Three days after starting baclofen therapy, the patient was found unconscious with Glascow coma scale of 3/15. The patient was shifted to the intensive care unit where he developed severe respiratory depression. The patient was intubated and ventilated and underwent hemodialysis. After Hemodialysis1, the patient regained consciousness but was drowsy and not moving the limbs. After Hemodialysis3, the patient became conscious, obeying and regained preoperative neurological status. The patient was extubated after 4 days and discharged on day 7. The serum baclofen concentration measured was 0.62 μg/ml (0.08–0.40 μg/ml) just prior to hemodialysis. The serum baclofen concentration declined to 0.10 μg/ml after Hemodialysis 2.{Figure 1}{Figure 2}

The exact mechanism of baclofen-induced neurotoxicity is poorly understood. Altered mental state is the commonest presentation. Baclofen toxicity usually presents 2–4 days after initiation of therapy but a period of up to 16 weeks has been described. Usually, patients recover well after Hemodialysis in a period ranging from hours to days.[3] Since baclofen is widely used for the control of spasticity as well as in other conditions, such as trigeminal neuralgia and hemifacial spasm; it is very much important for all of us to know that baclofen should be avoided in patients with impaired renal function. In an unfortunate situation where the patient develops features of toxicity, the treating physician should be aware that HD promptly reverses the toxicity.[4] Hemodialysis removes baclofen as effectively as normal kidneys.[5] The summary of various cases reported so far in the literature is summarized in [Table 1].{Table 1}

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