losartan metabolite
What it isThe carboxylic acid metabolite of losartan, a more potent and insurmountable AT1 antagonist.
Why it mattersIt provides most of losartan’s blood-pressure effect and its longer duration.
What it changesCYP2C9 poor metabolizers form less of it, which is why losartan underperforms in that group — the parent alone is weak.
NO BOXED WARNINGS
Principal riskLittle in its own right; see the parent drug
