OPC poisoning is one of the most medical emergencies manage in hospital in our country. For the treatment of this acute cases, along with the supportive measures, intravenous anticholinergic atropine is the mostly used antidote. WHO (World Health Organization) recommended the use of intravenous pralidoxime along with atropine for favorable outcomes, while several studies had doubted effectiveness of its use for the treatment of OPC poisoning. Therefore, the aim of this study is assessment of the outcomes of patients with OPC poisoning of moderate severity between two treatment groups one will be treated with atropine plus Pralidoxime and other with only atropine. This open level randomized controlled trail will be conducted in department of Medicine, Sir Salimullah Medical College \& Mitford Hospital, Dhaka. All the patient admitted in the hospital during the study period with OPC poisoning will be evaluated by clinical presentation. Form the total patients, those patients with the history of organophosphorus poisoning within previous 24 hours with clinical features of poison consumption with moderate severity after assessing by Peradeniya OP (POP) Scale and considering the inclusion and exclusion criteria; participant/patients will be enrolled in the study. A total 96 patients will be enrolled in the study. After inclusion in the study the participant will be randomly allocated following simple randomization technique in both treatment group \[atropine plus pralidoxime group (Group A) and atropine only group (Group B). The nature of the chemical composition of the organophosphorus compound will be identified from the brought sample.

The patients of group (A) will be treated with atropine plus pralidoxime and all the patients of group (B) will be treated with atropine only. All patients will receive other supportive therapy with stomach wash, i.v. fluid, antibiotics, and O2 inhalation as required. Every patient will be followed up by careful clinical examination. Patients developing respiratory failure will be identified by clinical examination and by using pulse oximetry. These Patients will be treated in ICU of Sir Salimullah Medical College \& Mitford Hospital and assisted ventilation support will be given. Both groups will be further analyzed from the start of poisoning to arrival at hospital and up to recovery/ ICU support/Death.

Each ampoule of inj atropine contained 0.6 mg atropine sulphate and each vial of inj. pralidoxime contained pralidoxime 1gm. Both drugs will be used in iv route. Inj. pralidoxime will be given as intravenous infusion over 4 minutes to avoid hypotension. Both antidotes will be administered as per recommended dosage schedule.

Inj. Atropine (3 ampule) will be given in intravenous route as a first dose, rapidly. Then the dose will be doubled from the previous dose in every 5 minutes interval until the signs of atropinisation appeared. Then infusion of 10% of the total bolus dose (the dose that was given until the signs of atropinisation appeared) per hour, will be given with intravenous Normal saline/ 5% DNS(Dextrose and Sodium chloride infusion) as a maintenance dose. The dose will be reduced for adjustment, based on clinical features/improvement. Inj. Pralidoxime 1 gm I/V will be given as first dose over 10-20 minutes. If no improvement of muscle weakness, then repeat the dose after one hour. Then 1 gram of Inj. Pralidoxime will be given at an 8-hour interval. The atropine and pralidoxime dose will be continued until symptomatic improvement and recovery. After discontinue of antidote further patient will be observed 24-48 hours then patient will be discharge. Study outcomes will provide any benefit of pralidoxime in moderately severe OPC poisoning patients.