Introduction Snake bites are common in interior of Sindh all the year round, but are increased manifold during the rainy season and floods. 1 Rural population and agricultural workers are most at risk. 1,2 Following snake bite, the venom predominantly produces either neurotoxic symptoms or cytolysis. Neurotoxins lead to respiratory paralysis and death if not managed promptly, while cytolytic venom causes tissue necrosis and bleeding due to damage to the vascular endothelial lining. 3 After a snake bite when patients come to hospital, the standard operating procedure is admission and evaluation for blood coagulation using 20-minute whole blood clotting (20MWBC) technique along with checking for neurotoxic symptoms. If the blood coagulates, no anti-venom is required and test is repeated every 30 minutes for 3 hours and then hourly for another 3 hours before the patient is discharged. If blood fails to clot, it means that the venom has disrupted the coagulation mechanism and in such cases anti-snake venom (ASV) is injected intravenously and coagulation checked after 6 hours. The dose of ASV is repeated if the blood still fails to coagulate and the procedure is repeated every 6 hours. 4 ASV produced in one country from its own indigenous snakes often do not work as effectively when used in other countries due to differences in snake varieties within the same species. In India, the ASV is produced from the snakes of Tamil Nadu, while in Pakistan it is produced from snakes of Sindh desert. 5 ASVs are imported in Pakistan from India as our indigenous production is low. In Pakistan, the National Institute of Health (NIH) is the only authorised site to produce ASV. The present study was planned to compare the efficacy and safety of Indian and Pakistani ASVs regarding the dose required to restore coagulation, side effects and the cost. Vol. 63, No. 9, September 2013 1129 ORIGINAL ARTICLE Comparative cost and efficacy trial of Pakistani versus Indian anti snake venom Huma Qureshi, 1 Syed Ejaz Alam, 2 Muhammad Ayaz Mustufa, 3 Nasreen Khalid Nomani, 4 Jawahar Lal Asnani, 5 Muhammad Sharif 6 Abstract Objectives: To compare the efficacy, safety and cost of Pakistani anti-snake venom with that imported from India Methods: The comparative cross-sectional study was conducted from June to September 2010 and comprised patients hospitalised following Krait snake bite in Mithi and Umerkot hospitals of Tharparker district who had incoagulable blood test on admission (20-minute whole blood clotting time). Basic demographies of patients, the site of bite and swelling around the bite and joints were entered in a proforma. For blinding, the liquid anti-snake venoms were packed in opaque polythene bags and marked as 'A' and 'B', and refrigerated. Four ampoules of the venom were mixed in a drip and given over one hour while looking for adverse reactions. In case of milder reactions, the venom was temporarily stopped and anti-histamines and analgesics were given. For more severe reactions intra- muscular adrenaline was recommended. Coagulation was again checked after 6 hours and, if blood was still incoagulable, the dose of the venom was repeated after 6 hours. Once coagulation was confirmed on two occasions, the patient was discharged. Total doses of the venom given to achieve coagulation, the reactions and the cost of the venom were analysed at the end to see the response and cost-effectiveness. Results: Of the 80 cases - 40 (50%) from each hospital - 6 (7.5%) had to be excluded for lack of data. Out of the remaining 74 (92.5%) patients, 38 (52.35%) received Pakistani anti-snake venom (A), and 36 (48.64%) received Indian anti-snake venom (B). Immediate reaction to the venom was seen in 23 (60.5%) cases with 'A' and 25 (69.4%) with 'B'. In terms of evenomation, 23 (60.5%) cases with 'A' attained restoration of coagulation with the first dose, compared to 13 (36.11%) with 'B', showing a significantly better response with 'A' (p <0.035). Mean of 1.66 doses of 'A' and 1.94 of 'B' were used to neutralise venom, again showing lesser doses of Pakistani anti-snake venom. Cost-wise 'A' was 2.5 times cheaper than the imported 'B'. Conclusion: Pakistani anti-snake venom was significantly quicker and better as well as cheaper than the Indian anti- snake venom. Keywords: Anti-snake venom, Pakistan, India. (JPMA 63: 1129; 2013) 1 Pakistan Medical Research Council, Islamabad, 2 PMRC Research Centre, Jinnah Postgraduate Medical Centre, 3 NICH, Karachi, 4 Biological Production Division, National Institute of Health, Islamabad, 5 Civil Hospital Mithi, 6 Civil Hospital Umar Kot, Sindh. Correspondence: Syed Ejaz Alam. Email: eazmu2004@yahoo.com