A cost effectiveness analysis of the preferred antidotes for acute paracetamol poisoning patients in Sri Lanka

Economic analysis was applied using public healthcare system payer perspective.Costs were obtained from a series of patients admitted to the National Hospital of Sri Lanka with a history of acute paracetamol overdose. Evidence on effectiveness was obtained from a systematic review of the literature. Death due to hepatotoxicity was used as the primary outcome of interest. Analysis and development of decision tree models was done using Tree Age Pro 2008.An affordable treatment threshold of Sri Lankan rupees 1,537,120/death prevented was set from the expected years of productive life gained and the average contribution to GDP. A cost-minimisation analysis was appropriate for patients presenting within 10 hours and methionine was the least costly antidote. For patients presenting 10-24 hours after poisoning, n-acetylcysteine was more effective and the incremental cost effectiveness ratio of Sri Lankan rupees 316,182/life saved was well under the threshold. One-way and multi-way sensitivity analysis also supported methionine for patients treated within 10 hours and n-acetylcysteine for patients treated within 10-24 hours as preferred antidotes.Post ingestion time is an important determinant of preferred antidotal therapy for acute paracetamol poisoning patients in Sri Lanka. Using n-acetylcysteine in all patients is not cost effective. On economic grounds, methionine should become the preferred antidote for Sri Lankan patients treated within 10 hours of the acute ingestion and n-acetylcysteine should continue to be given to patients treated within 10-24 hours.Paracetamol is the most common cause of drug poisoning in the world [1] and the single most commonly taken drug in overdoses that lead to hospital presentation and admission [2].Poisoning with paracetamol is an emerging problem in Sri Lanka with rapidly increasing admissions to the National Hospital of Sri Lanka (NHSL): from only 35 cases in 2003 to 515 cases in 2005 [3]. Paracetamol poisoning is one of the most exp