Problem:
In the mid 2000s in the US, due to issues of drug enforcement, pseudoephedrine containing medications were brought behind the pharmacy counter and in most cases require ID, and phenylephrine was substituted in most over-the-counter products.
Pseudoephedrine increases the amount of endogenous norepinephrine, whereas phenylephrine works on ?1-adrenergic receptors directly.
There are numerous cases where experts have spoken out about the effectiveness of phenylephrine, so it likely is a less effective substitute for pseudoephedrine in its main role as a decongestant.
Question: What I'm curious about is whether there are clinical indications for which the phenylephrine is actually preferred (so situations where the ?1-agonist nature without the increase of endogenous NE is sought after)?
Please explain the clinical indications for which the phenylephrine is actually preferred.