Day 12 Lab Results

 I will be monitored by labs every two weeks for the first two months to see how I am handling Verzenio. So far so good!

 My white cells are kicking butt. My red cells are a little low which is why I'm more tired, but not at a concerning level. My liver function tests are spectacular which is great since this is how Verzenio is metabolized. My kidney levels - creatinine is high and estimated glomerular filtration rate (eGFR) is low, but that is to be expected.

 Down the rabbit hole I go:

 Verzenio (abemaciclib) frequently raises blood creatinine levels by blocking kidney secretion transport, but it usually does not damage actual kidney function.

• Transporter Inhibition: Verzenio inhibits renal tubular transporters—specifically OCT2, MATE1, and MATE2-K.
• Decreased Secretion: These transporters normally help actively secrete creatinine into the urine.
• Elevated Blood Levels: When they are blocked, creatinine builds up in the blood stream (serum creatinine increases), making blood test numbers go up.

Key Clinical Facts

• Not Kidney Damage: Up to 95% of patients experience this rise, but it typically does not mean your kidneys are failing or injured. The actual filtration rate of the kidneys (GFR) remains normal.
• Timing: The increase usually happens early—often within the first 28-day cycle of taking the medication—and then stabilizes.
• Reversibility: The elevated creatinine levels are fully reversible and drop back to normal after stopping Verzenio.