1/8 - The Mystery

It's...

Metadata

• Author: @tony_breu on Twitter
• Full Title: 1/8 - The Mystery
  It's...
• Category: #tweets
• URL: https://twitter.com/tony_breu/status/1636078689233281027

Highlights

• 1/8 - The Mystery
  It's 1981, 10 years before filgrastim is approved by the FDA.
  You're hoping to mitigate chemotherapy-induced neutropenia in one of your patients.
  🤔What medication might provide this ELEMENT of cancer care? (View Tweet)
• 2/8 - The Answer
  LITHIUM!
  💡Soon after its use for bipolar emerged, LEUKOCYTOSIS was observed to be a common side effect.
  https://t.co/6FmK7ilhyR (View Tweet)
• 3/8 - The Evidence
  One 1970 report of 22 patients on lithium noted the following white blood cell counts (WBCs):
  ☞Pre-drug: 8,050
  ☞On lithium: 10,100
  Other series show that the WBC returns to baseline when lithium is stopped.
  https://t.co/0aacYCwVd1
  (View Tweet)
• 4/8 - The Mechanism
  Over the next decade, the mechanism of lithium-induced leukocytosis emerged.
  💡First, it became clear that lithium leads to the production of NEW neutrophils, not just redistribution of the marginated pool.
  https://t.co/aNTvGtFitN
  (View Tweet)
• 5/8 - The Mechanism
  💡Eventually we learned that lithium promotes neutrophil production by stimulating the synthesis of G-CSF.
  https://t.co/816sYTDLvG
  (View Tweet)
• 6/8 - The Application
  Armed with this mechanistic understanding, the late 70s and early 80s saw trials of lithium aimed at mitigating chemotherapy-induced neutropenia.
  One RCT found that lithium reduced rates of:
  ☞Neutropenia
  ☞Febrile neutropenia
  https://t.co/V5mlNIwoAQ
  (View Tweet)
• 7/8 - The Alternative
  Ultimately, filgrastim emerged as a more effective and safer alternative. This was demonstrated in a 1991 RCT showing reductions in neutropenic fever.
  That same year the FDA approved its use.
  And lithium faded away as an option.
  https://t.co/cK9Eljx9sd
  (View Tweet)
• 8/8 - Postscript
  Now when I see a patient with lithium-induced leukocytosis I'll recall this story.
  In a few brief years, an observation led to basic science's search for a mechanism and clinical medicine's application of that mechanism to patients.
  So cool! (View Tweet)