Baclofen/myoclonus/tramadol

Abstract

Baclofen/myoclonus/tramadolBaclofen overdose associated with various toxicities: case report A 68-year-old man developed various toxicities during treatment with pregabalin and tramadol and after overdose of baclofen and toxicity for chronic low back pain associated with muscle spasms [dosages and routes not stated].The man was brought to emergency room with an altered level of consciousness. A few hours prior to presentation, he started experiencing somnolence and later, loss of brainstem reflexes associated with multifocal myoclonus. After hospitalisation, ventilator and immediate intubation was required to protect his airway. His BP was 115/54 mmHg, HR was 54 beats/min and body temperature was 36.6°C. On neurological examination, it was noted that he was in deep coma, with 4mm fixed unreactive pupils, and absent corneal, oculocephalic and gag reflexes. His other examinations were unremarkable and no external signs of head injury was noted. However, he developed a generalised tonic-clonic seizure.The man was treated with IV diazepam, followed by loading dose of valproate. His serum creatine kinase was 702 IU/L (20-205) and venous lactic acid was 2.27 mmol/L (0.55-2.20). A urine toxicology screen was positive for benzodiazepines and opiates. No abnormalities were detected on head CT scan, CT-angiogram, chest X-ray and brain MRI. A 90 min EEG recording revealed a burst suppression (BS) pattern with bursts of mixed theta delta activity lasting 1 to 3 sec alternating with severe diffuse suppression of the background amplitude lasting 4 to 5 sec. Later, it was noted that his medical history was significant for chronic low back pain associated with muscle spasms, for which he had been receiving baclofen, pregabalin and tramadol. Considering this and current situation his past medications were stopped and blood samples were collected for baclofen and tramadol serum levels. His serum levels showed an elevated tramadol level was 1960 ng/mL (100-1000 ng/mL) and a toxic baclofen level was 4.30 µg/ml (0.08-0.6 µg/mL; toxic >1.1µg/ml). Later, he was shifted to the ICU, where his condition gradually improved over the subsequent 48 hours. On day 3, tubes were removed and he was following command at that time; however, he remained intermittently agitated and commenced on quetiapine. On the same day, his EEG showed resolution of the BS pattern with mild slowing. On day 9, he was discharged from hospital as no neurological deficits were noted.