Phenylephrine

Phenylephrine, sold under the brand names Neosynephrine and Sudafed PE among others, is a <a href="/facts/Medication/h9mhwWP2">medication</a> used as a <a href="/facts/Decongestant/Vthbc5a0">decongestant</a> for uncomplicated <a href="/facts/Nasal_congestion/xClWzxrg">nasal congestion</a> in the form of a <a href="/facts/Nasal_spray/zLm4BmWx">nasal spray</a> or oral tablet, to <a href="/facts/Mydriasis/19r5uMvC">dilate the pupil</a>, to increase <a href="/facts/Blood_pressure/VtqqSM2J">blood pressure</a> given <a href="/facts/Intravenous_therapy/AwwuD3Nu">intravenously</a> in cases of <a href="/facts/Hypotension/BhrdVVRS">low blood pressure</a>, and to relieve <a href="/facts/Hemorrhoids/wlInkR8T">hemorrhoids</a> as a <a href="/facts/Suppository/26njDQ8o">suppository</a>. It can also be <a href="/facts/Transdermal_administration/zFITIEjd">applied to the skin</a>.
Common <a href="/facts/Side_effect/PhuX2haY">side effects</a> when taken by mouth or injected include <a href="/facts/Nausea/dyhkcbeD">nausea</a>, <a href="/facts/Vomiting/R2vQkHqV">vomiting</a>, <a href="/facts/Headache/mdmmC9DP">headache</a>, and <a href="/facts/Anxiety/Geekl883">anxiety</a>. Use on hemorrhoids is generally well tolerated. Severe side effects may include a <a href="/facts/Bradycardia/70msP5HD">slow heart rate</a>, <a href="/facts/Intestinal_ischemia/DvReleG4">intestinal ischemia</a>, <a href="/facts/Angina/rT1brdwS">chest pain</a>, <a href="/facts/Kidney_failure/gsqb5nos">kidney failure</a>, and <a href="/facts/Tissue_death/zCPsTeWx">tissue death</a> at the site of injection. It is unclear whether its use during <a href="/facts/Pregnancy/vEKYGpep">pregnancy</a> and <a href="/facts/Breastfeeding/cdWXyYDX">breastfeeding</a> is safe. Phenylephrine is a <a href="/facts/Binding_selectivity/RryTsdGv">selective</a> <a href="/facts/Alpha-1_adrenergic_receptor/JbPCT974">α1-adrenergic receptor</a> <a href="/facts/Agonist/nz8U5NNp">agonist</a> with minimal to no <a href="/facts/Beta-adrenergic_receptor/uoAeJbcN">β-adrenergic receptor</a> agonist activity or <a href="/facts/Norepinephrine_releasing_agent/Ua8s5KKG">induction of norepinephrine release</a>. It causes <a href="/facts/Vasoconstriction/9hdY0aR2">constriction</a> of both <a href="/facts/Arteries/Y1Yj0jat">arteries</a> and <a href="/facts/Veins/I6ycr6gF">veins</a>.
Phenylephrine was patented in 1933 and came into medical use in 1938. It is available as a <a href="/facts/Generic_medication/IF6AXDVX">generic medication</a>. Unlike <a href="/facts/Pseudoephedrine/b2rMjnLv">pseudoephedrine</a>, abuse of phenylephrine is very uncommon. Its effectiveness as an oral nasal decongestant has been questioned. In 2023, a U.S. <a href="/facts/Food_and_Drug_Administration/rCEnh9WB">Food and Drug Administration</a> (FDA) panel concluded that the drug was ineffective as a nasal decongestant when taken orally, performing no better than placebo. In November 2024, the FDA proposed to remove oral phenylephrine as an active ingredient that can be used in over-the-counter (OTC) monograph drug products for the temporary relief of nasal congestion.

Phenylephrine open-in-new

Phenylephrine