Influence of genetic variations in ABCB1 on the clinical efficacy of ondansetron - A pharmacogenetic analysis of Pakistani population.

To study the association of C1236T single-nucleotide polymorphisms of ABCB1 gene with non-responsiveness to antiemetic treatment in post-operative patients.The prospective, clinical trial was conducted at Combined Military Hospital, Rawalpindi, and the Institute of Biomedical and Genetic Engineering, Islamabad, in 2012-13, and comprised patients undergoing elective laparoscopic cholecystectomy. All patients were given 0.1 mg/kg ondansetron intravenously 30 minutes before the end of surgery and Deoxyribonucleic acid samples were obtained. The frequencies of genotypes of Single Nucleotide Polymorphism were determined by polymerase chain reaction followed by restriction fragment length polymorphism.Of the 426 patients, 201(47%) were responders having no nausea or vomiting, and 225(52.8%) were non-responders having nausea or vomiting. The incidence of post-operative nausea and vomiting during the first 2 hours after surgery was significantly lower in patients with 1236TT genotype than other 1236 genotypes (p<0.001). It was significantly higher in patients with CC genotype at 2 hours than other 1236 genotypes (p<0.001).Polymorphism of ABCB1 gene may be a good guide for predicting responsiveness for ondansetron.