Search

Herein, we describe a case of an elderly patient with muscular dystrophy for whom control of the plasma vancomycin (VCM) concentration proved difficult when he developed a catheter-related bloodstream infection. The pharmacist initially carried out therapeutic drug monitoring using an estimate of the creatinine clearance (CL cr ) level, which was based on the serum creatinine (SCr) and serum cystatin-C (CysC) levels, but was ultimately unable to control the plasma VCM concentration. Therefore, the plasma VCM concentration was predicted ex post facto using population pharmacokinetic parameters as a covariate; that is, directly including the glomerular filtration rate (GFR CysC ) estimated from the CysC level, which is not affected by the muscle mass. As a result, the estimated VCM concentration was closer to the actual concentration than that predicted using CL cr . Furthermore, the results of examining the predictive accuracy according to the assessment of renal function at the time of initial VCM administration suggested that estimation of the trough concentration using GFR CysC might be useful in elderly patients with muscular dystrophy.

Although S-1 is frequently used in cancer chemotherapy, the drug interaction with warfarin, an anticoagulant agent, is not fully paid attention. In the present study, we investigated retrospectively the timing of expression of blood coagulation abnormality in nine patients treated with warfarin and S-1 concomitantly. In five patients, the dose of warfarin was reduced or interrupted after concomitant use of S-1. The International Normalized Ratio (INR) was significantly increased after combination with S-1 compared with the former value. In all patients, the INR was increased in three weeks after combination with S-1. On the other hand, serum creatinine, aspartate aminotransferase, alanine aminotransferase or serum albumin was not different before and after combination with S-1. These results suggest that the careful monitoring of the blood coagulation ability is necessary in all patients receiving warfarin and S-1 concomitantly.

Radiocontrast nephropathy (RCN) is a major complication after radiographical examination with iodinated contrast media (CM). Although little is known about the mechanism of RCN, a direct toxic action on renal cells and/or decrease in renal blood flow are considered to be implicated in the pathogenesis of the disease/the condition, A large number of vasodilatory agents, including endothelin antagonists, adenosine antagonists, atrial natriuretic peptide, calcium channel blockers, dopamine, dopamine D1 receptor agonist fenoldopam, and prostaglandin E1 have been tried clinically to prevent RCN, however, most of them have failed. Although prophylactic effects of antioxidant N-acetylcysteine have recently been reported by several investigators, only hydration is a universally accepted protocol to prevent it. In our recent in vitro and in vivo study, we have elucidated that CM induced apoptosis of renal tubular cells through the reduction in Bcl-2 expression and the subsequent activation of caspase-9 and caspase-3. Moreover, we found that CM caused an increase in ceramide content in renal tubular cells, which leads to apoptosis by inhibiting the phosphorylation of Akt and cAMP responsive element binding protein (CREB) and the subsequent reduction in Bcl-2 expression. The inhibitor of ceramide synthase, fumonisin B1, reversed both the elevation of ceramide content and renal cell injury induced by CM. On the other hand, a prostacyclin analog beraprost prevented RCN in mice by the increase of endogenous cAMP and subsequent CREB phosphorylation resulted in enhancement of Bcl-2 expression. These findings suggest that ceramide synthesis inhibitor or beraprost is potentially useful for the prophylaxis of RCN.