Objective: Suboptimal treatment of chemotherapy-induced nausea and vomiting and unsatisfactory response to antiemetic drugs cause impairment of cancer patient's daily functioning. This study was aimed to investigate the association of selected germline polymorphisms with ondansetron and metoclopramide response in Indonesian cancer patients treated with highly emetogenic chemotherapy. Methods: We enrolled 202 chemotherapy naïve patients treated with cisplatin at a dosage of !50 mg/m 2 as monotherapy or as combined chemotherapy. Ondansetron 8 mg and dexamethasone 8 mg intravenously were the standard antiemetic therapy for prevention of acute chemotherapy-induced nausea and vomiting. Metoclopramide 10 mg orally, three times per day as fixed prescription, was given until 5 days after chemotherapy to prevent delayed chemotherapy-induced nausea and vomiting. Primary and secondary outcomes were the occurrence of chemotherapy-induced nausea and vomiting in the acute and delayed phase. The following single-nucleotide polymorphisms were determined in ABCB1: rs1045642, rs2032582 and rs1128503; in 5-HT3B-R: rs45460698, rs4938058 and rs7943062; and in CYP2D6: rs16947 (CYP2D6*2), rs3892097 (CYP2D6*4) and rs1065852 (CYP2D6*10) using Taqman assays. Results: During the acute phase, 21.8 and 30.2% patients experienced Grade 3 and 4 nausea and vomiting, respectively, whereas 38.6% patients experienced nausea and/or vomiting in the delayed phase. Carriers of the CTG haplotype of the ABCB1 gene experienced Grade 3 and 4 chemotherapy-induced nausea and vomiting more often than other haplotypes in the delayed phase (P , 0.05). No associations were found with the 5-HT3B receptor haplotypes and CYP2D6-predicted phenotypes. Conclusions: Our study shows that in Indonesian cancer patients treated with highly cytostatic emetogenic, carriership of the CTG haplotype of the ABCB1 gene is related to an increased risk of delayed chemotherapy-induced nausea and vomiting.

Objective. Methotrexate (MTX) is the most commonly used disease-modifying antirheumatic drug in juvenile idiopathic arthritis (JIA). Currently, individual response to MTX cannot be reliably predicted. Identification of clinical and genetic factors that influence the response to MTX could be helpful in realizing the optimal treatment for individual patients. Methods. A cohort of 128 JIA patients treated with MTX were studied retrospectively. Eleven clinical parameters and genotypes of 6 single nucleotide polymorphisms in 5 genes related to the mechanism of action of MTX were compared between MTX responders and nonresponders using a multivariate regression analysis. Results. The time from diagnosis to start of MTX treatment, physician's global assessment at baseline, and the starting dose were significantly associated with the response to MTX at 6 months after initiation. Patients with a shorter time from diagnosis to start of MTX and a higher disease activity according to the physician but with a lower MTX dose showed an increased response. The effect of the starting dose on MTX response seemed to be mainly due to the influence of the systemic JIA subtype. The time from diagnosis to start of MTX treatment and physician's global assessment at baseline were highly correlated. Therefore, the precise effect size of each independent variable could not be determined. Conclusion. In children with JIA, the time from diagnosis to start of MTX appears to be an important factor for MTX response. Our results suggest that an earlier start of MTX treatment will lead to an increased response.

Objective To identify determinants for the discontinuation of non-ergoline dopamine agonist (DA) treatment in patients with Parkinson's disease (PD) and to identify genetic determinants in genes encoding dopamine receptor (DR)D2 and DRD3 in a exploratory analysis.Methods Patients included were first-time users of the nonergoline DA ropinirole or pramipexole who had been diagnosed with PD before 2005. Treatment discontinuation was defined as a gap of 180 days or more between two refills of the DA. Non-genetic determinants for discontinuation were studied in the overall population, and genetic determinants [DRD2 141C Ins/Del, DRD2 (CA) n STR, DRD2 TaqIA, DRD3 MscI single nucleotide polymorphism (SNP) and DRD3 MspI SNP] were studied in a subgroup. Cox proportional hazard analysis was used to estimate the hazard ratios (HR) for the discontinuation of non-ergoline DA treatment.Results The study population comprised 90 patients. Apomorphine use was associated with non-ergoline DA discontinuation, although the apomorphine group consisted only of three patients [HR 6.26; 95% confidence interval (CI) 1.85-21.2]. Daily levodopa dosages between 500 and 1000 mg were positively associated with discontinuation (HR 2.31; 95% CI 1.08-4.93). Included in the exploratory pharmacogenetic analysis were 38 patients. The absence of a 15× DRD2 CA repeat allele was significantly related with a decreased discontinuation of non-ergoline treatment (HR 0.23; 95% CI 0.07-0.81). The DRD3 MspI polymorphism showed a non-significant allele dose effect, suggestive of a causal relationship. Conclusion This study identified apomorphine use and levodopa dosages between 500 and 1000 mg as nongenetic and the 15× DRD2 CA repeat allele as genetic determinants for the discontinuation of non-ergoline DA treatment in patients with PD. More research is needed to replicate these findings.

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