title: Formulation changes and time trends in outcome following paraquat ingestion in Sri Lanka.
abstract: BACKGROUND
  Deliberate self-harm with pesticides is a significant public health problem in rural Asia. We have previously shown an improved survival of patients with paraquat self-poisoning following the introduction of a new formulation with an increased emetic concentration, an alginate and a purgative in Sri Lanka. Further, formulation changes were introduced in October 2006; this study was designed to assess the impact of these changes on 6-week mortality following paraquat ingestion.
  
  
  METHODS
  Prospective, cohort study of patients admitted with paraquat poisoning to 10 hospitals across Sri Lanka between September 2006 and September 2008.
  
  
  RESULTS
  Overall, there was a significant (p < 0.001) increase in survival in the 533 patients included in this study compared to previous data (44.5 vs. 35.2% before September 2006 and 27.1% before October 2004). Patients ingesting the new INTEON formulation had a higher survival rate than those ingesting standard formulation (40.2 vs. 31.0%), but this effect was not statistically significant in Cox's proportional hazards model (hazard ratio 0.81, 95% CI 0.61?1.08 (unadjusted) and 1.17, 95% CI 0.82?1.68 (fully adjusted), respectively).
  
  
  CONCLUSIONS
  This study has confirmed a continued improvement in survival of patients following self-harm with paraquat in Sri Lanka in recent years; however, in contrast to previous investigations, a beneficial effect associated with the INTEON formulation could not be substantiated. This may be partly due to the large number of patients in whom paraquat concentrations were too low for analytical confirmation of the formulation (n = 105) and who had a very high survival rate (86.7%).
authors.affiliation: Swiss Centre for Applied Human Toxicology, University of Basel, Switzerland. martin.wilks@unibas.ch
authors.forename: Martin F
authors.initials: MF
authors.lastname: Wilks
authors.forename: John A
authors.initials: JA
authors.lastname: Tomenson
authors.forename: Ravindra
authors.initials: R
authors.lastname: Fernando
authors.forename: P L
authors.initials: PL
authors.lastname: Ariyananda
authors.forename: David J
authors.initials: DJ
authors.lastname: Berry
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Buckley
authors.forename: Indika Bandara
authors.initials: IB
authors.lastname: Gawarammana
authors.forename: Shaluka
authors.initials: S
authors.lastname: Jayamanne
authors.forename: David
authors.initials: D
authors.lastname: Gunnell
authors.forename: Andrew
authors.initials: A
authors.lastname: Dawson
mesh_terms: D000293:Adolescent; D000328:Adult; D000464:Alginates / Q000008:administration & dosage; D002626:Chemistry, Pharmaceutical; D015331:Cohort Studies; D005260:Female; D020723:Glucuronic Acid / Q000008:administration & dosage; D006540:Herbicides / Q000506:poisoning*; D006603:Hexuronic Acids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D010269:Paraquat / Q000008:administration & dosage / Q000506:poisoning*; D011446:Prospective Studies; D016728:Self-Injurious Behavior; D013188:Sri Lanka; D015996:Survival Rate
chemical_list: D000464:Alginates; D006540:Herbicides; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D010269:Paraquat