Antagonistic effects of ondansetron and tramadol? A randomized placebo and active drug controlled study

Opposing effects of ondansetron and tramadol on the serotonin pathway have been suggested which possibly increase tramadol consumption and emesis when co-administered. In a randomized, double-blinded study, 179 patients received intravenous ondansetron, metoclopramide, or placebo for emesis prophylaxis. Analgesic regimen consisted of tramadol intraoperative loading and subsequent patient-controlled analgesia. Tramadol consumption and response to antiemetic treatment were compared. Additionally, plasma concentrations of ondansetron and (+)O-demethyltramadol and CYP2D6 genetic variants were analyzed as possible confounders influencing analgesic and antiemetic efficacy. Tramadol consumption did not differ between the groups. Response rate to antiemetic prophylaxis was superior in patients receiving ondansetron (85.0%) compared with placebo (66.7%, P = .046), with no difference to metoclopramide (69.5%). Less vomiting was reported in the immediate postoperative hours in the verum groups (ondansetron 5.0%, metoclopramide 5.1%) compared with placebo (18.6%; P = .01). Whereas plasma concentrations of (+)O-demethyltramadol were significantly correlated to CYP2D6 genotype, no influence was detected for ondansetron. Co-administration of ondansetron neither increased tramadol consumption nor frequency of PONV in this postoperative setting. PERSPECTIVE: Controversial findings were reported for efficacy of tramadol and ondansetron when co-administered due to their opposing serotonergic effects. Co-medication of these drugs neither increased postoperative analgesic consumption nor frequency of emesis in this study enrolling patients recovering from major surgery.

CYP2D6- and CYP3A-dependent enantioselective plasma concentrations of ondansetron in postanesthesia care

An influence of polymorphic cytochromes P450 (CYP) 2D6 genetic variants on antiemetic efficacy of ondansetron has been suggested. However, the role of CYP3A in ondansetron metabolism and efficacy has been unclear. In this study, we evaluated the hypothesis that genotype-dependent CYP2D6 and CYP3A activity selectively influences plasma concentrations of ondansetron enantiomers. Additionally, the effects of doubling the ondansetron dose on genotype-dependent plasma concentrations were investigated.

Comparison between the first and second generation bioresorbable vascular scaffolds: a six month virtual histology study

To compare the intravascular ultrasound virtual histology (IVUS-VH) appearance of the polymeric struts of the first (Revision 1.0) and the second (Revision 1.1) generation bioresorbable vascular scaffold (BVS).

Definitions and outcome measures for mucous membrane pemphigoid: recommendations of an international panel of experts

Mucous membrane pemphigoid encompasses a group of autoimmune bullous diseases with a similar phenotype characterized by subepithelial blisters, erosions, and scarring of mucous membranes, skin, or both. Although knowledge about autoimmune bullous disease is increasing, there is often a lack of clear definitions of disease, outcome measures, and therapeutic end points. With clearer definitions and outcome measures, it is possible to directly compare the results and data from various studies using meta-analyses. This consensus statement provides accurate and reproducible definitions for disease extent, activity, outcome measures, end points, and therapeutic response for mucous membrane pemphigoid and proposes a disease extent score, the Mucous Membrane Pemphigoid Disease Area Index.