Naphazoline

Naphazoline
Clinical data
Trade names	Naphcon-a
AHFS/Drugs.com	Monograph
Routes of; administration	Nasal route
ATC code	R01AA08 (WHO) S01GA01 (WHO);
Legal status
Legal status	In general: Over-the-counter (OTC);
Identifiers
	IUPAC name 2-(naphthalen-1-ylmethyl)-4,5-dihydro-1H-imidazole;
CAS Number	835-31-4 ;
PubChem CID	4436;
IUPHAR/BPS	5509;
DrugBank	DB06711 ;
ChemSpider	4283 ;
UNII	H231GF11BV;
KEGG	D08253 ;
ChEMBL	ChEMBL761 ;
CompTox Dashboard (EPA)	DTXSID3048449 ;
ECHA InfoCard	100.011.492
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) ; Key:CNIIGCLFLJGOGP-UHFFFAOYSA-N ;
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Naphazoline is a medicine used as a decongestant. It is a sympathomimetic agent with marked alpha adrenergic activity. It is a vasoconstrictor with a rapid action in reducing swelling when applied to mucous membrane. It acts on alpha-receptors in the arterioles of the conjunctiva to produce constriction, resulting in decreased congestion.

It was patented in 1934 and came into medical use in 1942.^[1]

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.

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.^[2]

Brand names

It is an active ingredient in several over-the-counter formulations including Rohto, Eucool, Clear Eyes and Naphcon eye drops.^[3]

References

^ Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 552. ISBN 9783527607495. {{cite book}}: Unknown parameter |name-list-format= ignored (|name-list-style= suggested) (help)
^ Zavala JA, Pereira ER, Zétola VH, Teive HA, Nóvak EM, Werneck LC (September 2004). "Hemorrhagic stroke after naphazoline exposition: case report". Arquivos de Neuro-Psiquiatria. 62 (3B): 889–91. doi:10.1590/S0004-282X2004000500030. PMID 15476091.
^ Green SM (2008). "Ophthalmology: Naphazoline". Tarascon Pocket Pharmacopoeia 2009. Jones and Bartlett. ISBN 978-0-7637-6572-9.

[Fis2006-1] Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 552. ISBN 9783527607495. {{cite book}}: Unknown parameter |name-list-format= ignored (|name-list-style= suggested) (help)

[pmid15476091-2] Zavala JA, Pereira ER, Zétola VH, Teive HA, Nóvak EM, Werneck LC (September 2004). "Hemorrhagic stroke after naphazoline exposition: case report". Arquivos de Neuro-Psiquiatria. 62 (3B): 889–91. doi:10.1590/S0004-282X2004000500030. PMID 15476091.

[3] Green SM (2008). "Ophthalmology: Naphazoline". Tarascon Pocket Pharmacopoeia 2009. Jones and Bartlett. ISBN 978-0-7637-6572-9.

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