Biesenbach P, et al. - Researchers undertook this study to investigate the pharmacokinetics of a 20 mmol magnesium bolus in regards to serum and urinary magnesium concentration, volume of distribution, and half-life. They found a significant but short-lived increase of magnesium serum concentration resulting from magnesium bolus therapy after cardiac surgery, attributed to renal excretion and distribution. It was also noted that the magnesium balance was neutral after 12 hours.