[A case of acute kidney injury during warfarin therapy].

The patient was an 82-year-old female. She had been treated with warfarin for atrial fibrillation that developed after a heart valve replacement operation. She was admitted because of a progressive loss of renal function together with persistent microscopic hematuria and proteinuria. Although the renal biopsy showed only focal mononuclear cell infiltration and mild mesangial expansion in the glomeruli, the occlusive red blood cell casts were remarkable in the tubules and were accompanied by inflammatory and edematous changes in the surrounding interstitial area. After the adjustment of an excessively extended prothrombin time, her renal function gradually improved in parallel with the marked decrease in the microhematuria. It was assumed that an acute kidney injury observed in this case was caused by the occlusive red blood cell casts as a result of abnormal hemorrhage in the glomeruli due to focal glomerulonephritis and a warfarin overdose. The present case, therefore, suggests that a warfarin overdose is a potential risk factor for acute kidney injury in the presence of coexisting glomerular injury.

Pharmacokinetics and pharmacodynamics of low doses of midazolam administered intravenously and orally to healthy volunteers.

1. Midazolam, a short-acting benzodiazepine, has been considered a probe for estimating hepatic and intestinal cytochrome P450 (CYP) 3A activity in humans. The aim of the present study was to evaluate the pharmacokinetics and pharmacodynamics of midazolam administered intravenously (i.v.) and orally (p.o.) at relatively low doses to healthy volunteers. 2. The present study was an open-label, single-sequence trial in three phases distinguished by differing doses of midazolam. Plasma concentrations of midazolam and its metabolites, as well as pharmacodynamic parameters, were measured simultaneously after administration of 5, 15 and 30 microg/kg, i.v., midazolam and 15, 50 and 100 microg/kg, p.o., midazolam. 3. The area under the concentration-time curve (AUC) of midazolam was significantly correlated with dose after both i.v. and oral administration (both P < 0.001). The AUC(0-6) of midazolam after oral administration was also well correlated with the area under the effect curve for peak saccadic velocity (PSV; P < 0.018), postural sway area (PSA; P < 0.069) and mental sedation as measured on a visual analogue scale (VAS; P < 0.054), but not for critical flicker fusion. 4. The present study has shown that the pharmacokinetics of midazolam at relatively low doses are linear for both intravenous and oral dosing regimens. In addition, PSV, PSA and VAS may be useful for the simultaneous evaluation of the pharmacokinetics and pharmacodynamics of midazolam at subtherapeutic doses.

Severe neutropenia with gelatinous bone marrow transformation in anorexia nervosa: a case report.

A 28-year-old woman with a history of anorexia nervosa was admitted with excessive weight loss, edema, and amenorrhea. She had lost 34% of her previous body weight within 2 years, and her body mass index was 12.3 kg/m(2). The leukocyte count on admission was 2150/microl and gradually decreased to 980/microl (neutrophils; 276/microl). Bone marrow biopsy disclosed gelatinous transformation with hypocellularity. After the patient was treated with intravenous nutritional support, the severe neutropenia improved to the level on admission. Hematological abnormalities seem to be common in anorexia nervosa, but severe neutropenia with gelatinous bone marrow transformation has rarely been reported.