ACMT Toxicology Visual Pearl: Is the Silver Bullet for Refractory Vasoplegia Really Blue?

What is the proposed mechanism for the pictured antidote when used as a pressor for refractory vasoplegic shock?

1. Alpha-1-adrenergic agonist
2. Angiotensin II receptor antagonist
3. Nitric oxide/cyclic GMP pathway inhibition
4. Vasopressin-1 receptor agonist

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