Naphazoline

Naphazoline

Names
Trade names	Naphcon-a, Clear Eyes Red Relief, Visine A, others
IUPAC name 2-(naphthalen-1-ylmethyl)-4,5-dihydro-1H-imidazole
Clinical data
Drug class	Alpha adrenergic agonist
Main uses	Stuffy nose, eye redness
Side effects	Burning, blurry vision
Routes of use	Nasal spray, eye drops
External links
AHFS/Drugs.com	Monograph
Legal
Legal status	In general: Over-the-counter (OTC)
Chemical and physical data
Formula	C14H14N2
Molar mass	210.274 g·mol−1
3D model (JSmol)	Interactive image
SMILES N\1=C(\NCC/1)Cc2cccc3c2cccc3
InChI InChI=1S/C14H14N2/c1-2-7-13-11(4-1)5-3-6-12(13)10-14-15-8-9-16-14/h1-7H,8-10H2,(H,15,16) Y Key:CNIIGCLFLJGOGP-UHFFFAOYSA-N Y

Naphazoline, sold under many brand names, is a medication used to treat a stuffy nose or eye redness due to minor irritation. It is available as a nasal spray or eye drops.

Common side effects include blurry vision and stinging. Other side effects may include recurrence of stuffiness following stopping use, headache, palpitations, and nervousness. Safety in pregnancy is unclear. It works by activating alpha adrenergic receptor which cases small arteries to narrow.

Naphazoline was patented in 1934 and came into medical use in 1942. It is available as a generic medication and over the counter. In the United States 15 ml of solution costs about 14 USD.

Medical use

Dosage

It is used at a dose of 1 to 2 eye drops every 3 to 4 hours.

Side effects

A few warnings and contraindications that apply to all naphazoline-containing substances intended for medicinal use are:

• Hypersensitivity to naphazoline
• Patients taking MAO inhibitors can experience a severe hypertensive crisis if given a sympathomimetic drug such as naphazoline HCl
• Use in infants and children can result in central nervous system depression, leading to coma and marked reduction in body temperature
• Should be used with caution in patients with severe cardiovascular disease including cardiac arrhythmia and in patients with diabetes, especially those with a tendency toward diabetic ketoacidosis
• Drug interactions can occur with anaesthetics that sensitize the myocardium to sympathomimetics (e.g. cyclopropane or halothane cautiously)
• Exercise caution when applying prior to use of phenylephrine.
• Extended use may cause rhinitis medicamentosa, a condition of rebound nasal congestion.

A possible association with stroke has been suggested.

Chemistry

The non-hydrochloride form of Naphazoline has the molecular formula C₁₄H₁₄N₂ and a molar mass of 210.28 g/mol. The HCl salt form has a molar mass of 246.73 g/mol.

Society and culture

Brand names

It is an active ingredient in several over-the-counter formulations including Rohto, Eucool, Clear Eyes and Naphcon eye drops.

External links

Identifiers:	ATC code: R01AA08 (WHO) S01GA01 (WHO) CAS Number: 835-31-4 N PubChem CID: 4436 IUPHAR/BPS: 5509 DrugBank: DB06711 Y ChemSpider: 4283 Y UNII: H231GF11BV KEGG: D08253 Y ChEMBL: ChEMBL761 Y