Saturday June 2, 2007
Linezolid infusion and exposure to light

Case: You have a patient diagnosed with vancomycin-resistant enterococci (VRE) and has been started on linezolid (Zyvox). While evaluating patient at bedside you saw a bag labelled with linezolid, due to infuse in 30 minutes. What would be your instruction to pharmacy ?

Answer: To protect the infusion bag of linezolid from light. Linezolid infusion bag need to be protected from light while awaiting infusion to avoid degradation. Once infusion is started, bag can be unwrap.Note: IV Zyvox may exhibit a yellow color that can intensify over time, but it is a benign effect and does not affect potency.


Reference: click to get abstract

1. Zyvox - rxlist.com

Friday June 1, 2007
Phosphate level in acetaminophen-induced acute liver failure

Case: You transferred a patient from nearby community hospital with acetaminophen-induced acute liver failure. ALT / AST reported in thousands and last PT-INR of 2.7. On clinical exam patient is alert and oriented. Hemodynamics are stable. You alerted the hepatology team and send STAT labs. After 45 minutes you received a call from lab with 'critical value' of phosphate with 0.9 mg/dl. Is it a good sign or a bad sign?

Answer: Good SignHypophosphatemia in the setting of acetaminophen-induced acute liver failure is a good sign. It indicates regeneration of hepatocytes and reversal of acute liver failure. You may have to replace it aggressively.Conversely, hyperphosphatemia suggest impaired regeneration and is a poor prognostic sign and actually also said to be a sign of impending hepato-renal failure due to kidney's lost ability of lowering of serum phosphate 1.

Related previous pearl: Is serum phosphate level better than King’s College Hospital criteria in Tylonol Toxicity ?


Reference: click to get abstract

1. Serum Phosphate Is an Early Predictor of Outcome in severe Acetaminophen-Induced Hepatotoxicity , Hepatology, Volume 36, Issue 3 , Pages 659 - 665