Effects of reduced glutathione (GSH) on oxaliplatin pharmacokinetics (OXA pk) and on Pt-DNA adducts formation in advanced colorectal cancer patients treated by FOLFOX4 regimen

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Background: Neurotoxicity is a common OXA toxicity in FOLFOX4 regimen for patients with advanced colorectal cancer. Recently, Cascinu et al. (JCO 2002; 20: 3478–3483) provided evidence that GSH reduces the OXA-induced neurotoxicity, but GSH influence on the formation of Pt-DNA adducts still remains unknown. This study evaluated the effect of GSH addition on OXA pk and on Pt-DNA adducts formation Table of Contents Methods: 28 patients were given twelve FOLFOX4 courses and randomized to receive either GSH 1,500 mg/m2 or normal saline solution (placebo) before OXA iv infusion. OXA pk and Pt-DNA adducts formation were evaluated at courses 5, 9 and 12. Total and ultrafiltered platinum were analyzed by atomic adsorption, Pt-DNA adducts in leukocytes (as model for tumour tissue) by adsorptive stripping voltammetry. Pk analysis were done by non-compartmental analysis, statistical analysis by non-parametric Mann-Whitney test. Results: Median total and ultrafiltered platinum median Cmax and AUCtot values were comparable to previously reported ones, being higher in the placebo arm, due to a moderate reduction of platinum clearance. The formation of Pt-DNA adducts was more pronounced in GSH arm (median value 20.3 Pt atoms/106 nucleotides vs. 5.7 Pt atoms/106 nucleotides), even not statistically significant. Conclusions: The addition of GSH to FOLFOX4 regimen is able to reduce the OXA-induced neurotoxicity, without affecting either the OXA pk behaviour or the formation of Pt-DNA adducts, without modifying FOLFOX4 clinical efficacy.

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No significant financial relationships to disclose.

Rubidium deficiency in dialysis patients

BACKGROUND

Since dialysis has brought long-term survival to uremic patients, we can now speculate on more subtle problems derived from imbalance or sub-optimal regulation of some elements such as trace metals. We focused on the rubidium (Rb) status in dialysis patients (HD), as concerns about its possible deficiency have been raised.

METHODS

Rb in uremic patients was evaluated by: A) serum concentration (graphite furnace atomic absorption spectroscopy) from blood samples of 70 patients on chronic hemodialysis (HD) in comparison with 75 controls; B) tissue concentration (neutron activation analysis) from autopsy or biopsy samples (20) of HD patients in comparison with 21 controls; C) in vivo intradialytic mass balance during standard bicarbonate dialysis in 8 HD patients.

RESULTS

A) Serum Rb concentrations in HD patients significantly were lower than in normal controls (304 +/- 81 micrograms/L versus 350 +/- 74 micrograms/L p < 0.001, log-transformed 5.68 +/- 0.28 versus 5.84 +/- 0.20, p < 0.001). Univariate logistic regression analysis found a significantly higher risk of serum Rb < 250-300 and 350 micrograms/L in uremic patients than in controls (Odd ratios or 12.6, 95% CI 2.77-57.04; 4.0, 95% CI 1.92-8.4; 2.08, 95% CI 1.02-4.25, respectively). B) Rb was significantly lower in tissues of HD patients, including brain (2250 +/- 1520 ng/g versus 5490 +/- 1250 ng/g, p = 0.0002) than normal controls. C) Rb was transferred from the patients' blood to the dialysis bath during a standard bicarbonate dialysis session, giving mean intradialytic Rb removal of 4.0 +/- 1.1 mg/session.

CONCLUSIONS

These results confirm that Rb deficiency may arise in uremic patients, and indicate that diffusive dialysis treatments allow Rb removal which, however, with a standard bicarbonate schedule does not seem to be any greater than that expected with normal urine output (20 mg/week). Further studies are needed to clarify the roles of many factors in this Rb deficiency, including the effects of uremia by itself, pre-dialysis factors (diet, impaired renal function and drugs), dialysis procedures (frequency, hours, diffusive/convective components) or other biochemical/clinical parameters (hemoglobin, body mass index, age). The finding of a Rb deficiency in uremia is important as it has a role in neurobehavioural functions, mainly as an antidepressant. As Rb deficiency may be implicated in central nervous system alterations which strongly influence the quality of life, we believe that monitoring serum Rb in uremic patients and clarifying the causal mechanisms of deficiency will facilitate future therapeutic approaches.

Integrating a clinical service line for maternal-child health

Clinical integration is a developmental process that calls on the combined resources, expertise, and knowledge of individuals who may be working together for the first time. The process is dependent on the acknowledgment of the value of integration and a shared vision for the service line. By using a strategic thinking and planning process, the service line can be reshaped to function as an integrated system of programs and services that is sensitive to needs at a local level. While the task of integration is not an easy one, the outcomes of the process lead to a synergy that cannot be realized in any other manner.