[Acute beta 1-selective beta-receptor blocker nebivolol poisoning in attempted suicide]

Abstract

History and admission findings: A 17-year-old girl had swallowed 80-100 tablets of Nebivolol, 5 mg each, with suicidal intent. She was referred to hospital 8 hours later by an emergency duty physician. On admission she was sweaty and pale, but there were no other obvious abnormalities. Neurological examination revealed decreased responsiveness and slowed movements. She was known to have type 1 diabetes mellitus.

Investigations: Blood pressure was 105/55 mmHg, the ECG showed sinus bradycardia of 55 beats/min. Biochemical tests revealed hypoglycaemia (2.1 mmol/l), hypokalaemia (3.4 mmol/l) and respiratory failure (pO2 6.16 kPa, O2 saturation 82%, pCO2 6.55 kPA). Heart and lung were unremarkable on physical examination as were chest radiogram and echocardiogram. Plasma level of nebivolol was 480 ng/ml on admission (therapeutic range 88-195 ng/ml).

Treatment and course: After gastric lavage and administration of charcoal and sodium sulphate a temporary pacemaker was connected and glucagon infused intravenously as an antidote. The cardiovascular state stabilized with falling plasma level of nebivolol. Glucose was administered initially, but transient intravenous insulin infusion became necessary to counteract hyperglycaemia. The patient was transferred from the intensive care unit in a stable cardiovascular state after 2 days.

Conclusion: This case demonstrates that swallowing 400-500 mg nebivolol, resulting in a plasma level of 480 ng/ml, need not be fatal. But the outcome in this patient should not be taken as necessarily applying to similar cases. It depends on the individual patient's metabolic state whether higher plasma levels might be reached with the same amount of ingested nebivolol.