The Use of Self-reported Symptoms as a Proxy for Acute Organophosphate Poisoning Among Nepali Farmers

The Use of Self-reported Symptoms as a Proxy for Acute Organophosphate Poisoning Among Nepali Farmers: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02838303

Enrollment

Registered

2016-07-20

Start date

2014-09-30

Completion date

2014-11-30

Last updated

2023-07-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Organophosphate Poisoning

Brief summary

The purpose of this study is to evaluate self-reported symptoms as a proxy for acute organophosphate poisoning by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure among farmers in Nepal.

Interventions

OTHEROrganophosphate

Chlorpyrifos 50% plus cypermethrin 5%, WHO Class II: Moderately hazardous

OTHERPlacebo

Multineem, WHO Class U: Unlikely to present acute hazard in normal use

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

DIAGNOSTIC

Masking

DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender

MALE

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* male * minimum age 18 years * hand pressured backpack sprayer usage * used to spray with moderately to extremely hazardous pesticides according to the World Health Organization's (WHO) Pesticide Hazard Classification

Exclusion criteria

* usual personal protective equipment use (respirator/mask with particulate filter, face shield, googles, gloves, boots, plastic poncho) * unwilling to stay pesticide-free seven days prior to each of the two spray sessions * medical conditions interfering with PchE activity (liver disease, acute infection, chronic malnutrition, heart attack, cancer, obstructive jaundice, inflammation caused by various diseases, or use of pyridostigmine drugs)

Design outcomes

Primary

Measure	Time frame	Description
Change in self-reported acute organophosphate poisoning symptoms from baseline to follow up	Obtained just before (baseline) and 30 minutes after (baseline) each spray session	Obtained using a structured questionnaire interview. The definition of symptoms was based on WHO's standardized list of clinical presentations of acute organophosphate poisoning.
Change in Plasma Cholinesterase (PchE) activity from baseline to follow up	Obtained just before (baseline) and 30 minutes after (baseline) each spray session	PchE activity was measured with a blood test using a Test-mate Che Cholinesterase System (Model 400) with a PchE Plasma Cholinesterase Assay Kit (Model 470).

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 11, 2026