Background: Drugabuse is a majorproblemin Iran with ahugesocial burden. MethadoneMaintenance treatment(MMT)is offered as a harm reduction program to decrease the consequences of opioid drug dependence. Single nucleotide polymorphisms (SNPs) in the ABCB1 gene, encoding P-glycoprotein, have shown associations with drug uptake in the central nervous system (CNS). Objectives: We aimed to identify the frequency of ABCB1 SNPs and haplotypes in Iranian opioid-dependent patients and the link between ABCB1 haplotypes and P-glycoprotein function. Methods: We randomly selected 400 patients undergoing methadone treatment from the MMT clinics in Shahroud, Iran. Of these, 320 people qualified for the study were sorted according to their dose requirement. Individuals with a dose of greater than 100 mg/day and less than 60 mg/day were selected and divided into two groups. Blood samples were taken from 83 high-dose dependent (HDD) and 86 low-dose dependent (LDD) individuals. DNA was extracted and ABCB1 SNPs at the C1236T, C3435T, A61G, G1199A, and G2677T loci were detected using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). The haplotypes were obtained by the use of SNP analyzer version 2. 0 software. Results: No significant differences were observed in allele and genotype frequencies of the SNPs between HDD and LDD groups. Eleven unique haplotypes were obtained, of which only the TTAGG haplotype showed a significant difference between the two populations (P = 0. 030557,  2 = 4. 678). Linkage disequilibrium was observed at 1199, 1236, and 3435 loci. There were no significant differences in methadone dose requirement between different haplotypes or genotypes. Conclusions: Here, for the first time, we reported the frequency of ABCB1 SNPs in opioid-dependent people in Iran. Regarding the results, it seems that the use of these SNPs is not beneficial to predict and optimize the amount of drug requirement in Iranian society. However, further genotyping studies are required to decipher the impact of genetic variability on methadone dependence.

Background: The role of methadone in QTc prolongation, Torsades de Pointes (TdP) arrhythmia and sudden cardiac death has been debated. Because of widespread use of methadone in methadone Maintenance treatment (MMT) centers, we aimed to study dose related effects of methadone on QTc prolongation.Methods: In a comparative observational study, 90 patients who were under MMT were evaluated. Patients were divided into three groups according to methadone daily dose (G1: 0-59 mg, G2: 60-109 mg, G3: 110-150 mg). Twelve-lead electrocardiograms (ECG) were performed at baseline and two months later, after reaching the maximum daily dose of methadone. The QTc were calculated for each patient. Comparison of mean QTc and mean QTc prolongation between baseline and follow up ECGs were analyzed.Results: In total, mean (SD) age was 32.4 (8.5). TdP was not detected in any patients. Mean QTc was 405.2 (17.0) and 418.5 (23.1) msec before and two months after MMT respectively. There was a significant difference between mean QTc in each group before and after treatment (P<0.001). In total, mean QTc prolongation was 13.5 (8.1). Univariate analysis showed that there was a significant difference in means of QTc prolongation between G1 and the other two groups (P=0.001), but not between G2 and G3. This indicates that patients receiving methadone over 60 mg/day are at a risk of greater QTc prolongation.Conclusion: Methadone can cause QTc prolongation in different doses. However, the extent of this effect is dose dependent. Daily dose of less than 60 mg methadone is a safer cardiac dose. Nevertheless, it is not possible to administer this low dose for all opioid addict patients. Therefore, it is necessary to closely monitor patients under MMT, especially those receiving higher methadone doses, with constant scheduled ECGs before and during treatment.

Background: Given the importance of the effect of muscle relaxants on the extubation time in coronary artery bypass grafting (CABG) patients, we sought to assess the difference in "time to extubation" and "intensive care unit (ICU) length of stay" between the primary bolus doses of Pancuronium and Cisatracurium without using the Maintenance dose of them during surgery.Methods: This double blind clinical trial divided 110 patients into two equal groups receiving either Cisatracurium or Pancuronium. The patients’ surgical and cardiopulmonary bypass variables were evaluated, and the extubation time and ICU length of stay were compared between the two groups.Results: There was no difference between the two groups regarding the depth of anesthesia, train-offour (TOF) scores at the beginning of anesthesia, and the surgical and cardiopulmonary bypass variables. However, the Cisatracurium patients were extubated earlier and had a shorter ICU length of stay than the Pancuronium patients.Conclusion: An appropriate depth of anesthesia facilitates the administration of the induction dose of Cisatracurium, which confers earlier extubation and shorter ICU length of stay by comparison with Pancuronium.