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1 The elimination and anticoagulant activity of a single intravenous dose of warfarin (1.0‐1.2 mg/kg) without and with concomitant cholestyramine treatment (about 4 g three times daily) was studied in five healthy male subjects. 2 Cholestyramine treatment decreased the biological half‐life of plasma warfarin (from a mean value of 2 days − 1.3 days) and increased the total clearance of this drug (from a mean value of 37 ml kg‐1 day‐1–53 ml kg‐1 day‐1). 3 The total anticoagulant effect per dose of warfarin, as measured by the area under the effect v time curve, was also reduced by cholestyramine (average reduction of about 25%). 4 Warfarin possibly undergoes enterohepatic recycling in man which can be interrupted by cholestyramine.

Hemodynamic response to graded immersion was studied in healthy male subjects in a thermoneutral bath in the sitting position. Pressures in the right heart and cardiac output were determined by means of a semifloating catheter with a thermistor probe. Pressures in the right atrium, pulmonary artery and in pulmonary wedge position increased with increasing depth of immersion, cardiac output was likewise augmented. Heart rate decreased from rest to hip immersion but remained constant from hip to head out water immersion. Plasma norepinephrine concentration remained constant throughout the experiment. The reported changes depend on the blood shift from capacitance vessels into the thoracic cavity. From this, preload increased and cardiac performance was improved. However, in patients with disturbed left ventricular function, immersion to the neck may be potentially hazardous due to augmented left ventricular filling pressure.