ence. The protocol for this trial and supporting 
CONSORT checklist are available as supporting information; see Checklist S1 and Protocol S1. The main endpoint was bioavailability. Even though the study was not designed to test clinical efficacy, patients evaluated PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19632594 their emetic symptoms by completing a diary. Toxicity was assessed using Common Toxicity Criteria for adverse events version 3.0.. All patients signed written informed consent before treatment. Blood was drawn in purchase BAY41-2272 heparin tubes, centrifuged and frozen at 220uC until analysis. Urine was collected for 12 hours after treatment. Palonosetron levels were determined by a validated high performance liquid chromatography with mass/ mass detection after liquid/liquid extraction of acidified plasma samples. The quantitation limit was 0.1 ng/ml. Calibration curves were prepared at a concentration range of 0. 1100 ng/ml. Plasma concentrations were analyzed by a laboratory certified in Good Laboratory Practices. Pharmacokinetic parameters were calculated by noncompartimental methods. All calculations were carried out using WinNonlin Professional Version 5.3. Pharmacokinetics of Subcutaneous Palonosetron volunteer decision to leave the study, death due to disease progression and chemotherapy related neutropenia. Patient characteristics are described in table 1. Gender distribution was 18 male and 7 female. Mean age was 58 years and mean body mass index 27.2 kg/m2. study drug were headache, diarrhoea, hiccups, dizziness, skin rash and bruise in the injection site. All these events were grade 1 and 2 and none were significantly more frequent with either administration route. Discussion Pharmacokinetic assessment Pharmacokinetic parameters are presented in table 2. Maximum plasma concentrations were observed right at the end of the IV infusion and 15 minutes after SC administration. Cmax obtained after SC route was 15% of that one achieved by IV administration. Mean palonosetron plasma concentrations are presented on figures 1 and 2. AUC024h and urinary elimination were similar between both routes, indicating similar bioavailability with a relative F of 1.18. Other pharmacokinetic parameters, such as t1/2 and ke were not statistically different. In this study, we have shown that palonosetron presents similar bioavailability when administered by either SC or IV route, confirming non-significant differences in AUC and urinary recovery between both routes. Therefore SC palonosetron seems a valid alternative to IV administration for control of emesis. This route could be of particular interest when conventional routes are difficult or impossible to use, for example, when heavy vomiting precludes oral intake or when IV administration is not possible in an outpatient setting. In addition, the SC route might be an interesting alternative for patients receiving oral chemotherapy that do not require IV medication. Guidelines for management of emesis recommend the use of palonosetron with chemotherapy of PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19630872 moderate and high emetic potential, and with chemotherapy regimens lasting over one day . We used a 250 mg dose of palonosetron since higher doses have not shown superior anti-emetic effect. The observed t1/2 for the SC e IV routes were respectively 14.68 hours and 12.71 hours, within the range observed in Efficacy and toxicity assessment From 25 patients evaluable for antiemetic efficacy, 11 reported no differences in antiemetic control between both alternatives, 6 had less emesis with SC palonosetron