Phenylephrine is used in popular versions of Sudafed, Dayquil and other medications, but experts have long questioned its effectiveness. The Food and Drug Administration formally proposed revoking ...

Phenylephrine is used in popular versions of Sudafed, DayQuil and other medications ... Because of its cardiovascular effects, the drug is sometimes used to treat dangerously low blood pressure ...

Hypertensive crisis with MAOIs. Increased risk of hepatotoxicity with ≥3 alcoholic drinks/day. β-blockers may increase the pressor effects of sympathomimetics. Antagonizes antihypertensives.