The need-to-know information for Phenylephrine


Pearls and Fun Nuggets

1.Phenylephrine was designed as a safer alternative to pseudophedrine ✔ This is due to pseudoephedrine’s use in the illicit manufacture of methamphetamine.

2. Its efficacy as an oral decongestant has been questioned  😐 Two studies published in 2009 examined the effects of phenylephrine on symptoms of allergic rhinitis by exposing people to pollen in a controlled, indoor environment. Neither study was able to distinguish between the effects of phenylephrine or a placebo. Pseudoephedrine and loratadinemontelukast therapy were found to be significantly more effective than both phenylephrine and placebo.[6][7]

3. Phenylephrine can be used topically to prevent symptoms of hemorrhoids 🍑 Phenylephrine causes the constriction of vascular smooth muscle and is often used in the treatment of hemorrhoids presumably to narrow the swollen veins and relieve the attendant pain. However, veins—unlike arteries—contain less vascular smooth muscle in their walls so the mechanism by which pain relief is achieved is likely related to something other than vascular change alone.

4. Phenylephrine is used as an eye drop 👀 It can dilate the pupil to facilitate visualization of the retina. It is often used in combination with tropicamide as a synergist when tropicamide alone is not sufficient.

5. Phenylephrine is commonly used for shock 😱 As a vasopressor, it increases the blood pressure in unstable patients with hypotension, especially resulting from septic shock.

Patient Perspectives

“Doesn’t work. Pseudoephedrine works the best for me”


“People say that this drug isn’t effective but it really is for me. I have tried so many drugs in the past for nasal relief and this drug works wonders for me. Whenever I have a really bad stuffy nose, I turn to phenylephrine because it works. “


“Taking Phenelephrine before bed time allows me to breath all night thru nose while wearing sleep apnea mask which I could not do most nights. I take one 10mg pill before bedtime only, do not use at any other time. Has also stopped my post nasal drip problem.”

Brandon Simpson, PA-C
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