Naphazoline

Naphazoline
Clinical data
Trade names	Clear Eyes, Cleari, Naphcon-A, Rohto
AHFS/Drugs.com	Monograph
Routes of; administration	Ophthalmic drug administration, nasal administration
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	210.280 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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Last updated February 06, 2025

Naphazoline is a medicine used as a decongestant, and a vasoconstrictor added to eye drops to relieve red eye. It has a rapid action in reducing swelling when applied to mucous membranes. It is a sympathomimetic agent with marked alpha adrenergic activity that acts on alpha-receptors in the arterioles of the conjunctiva to produce constriction, resulting in decreased congestion.

Medical uses

Nasal administration

Nasal decongestant.^[2]

Ophthalmic drug administration

Eye drops (brand names Clear Eyes, and Cleari) narrowing swollen blood vessels (ophthalmic arteries, and ophthalmic veins) to relieve red eye.^[2]

Temporary red eye can safely be treated when the cause of the redness is established (e.g. cannabis induced conjunctival vasodilation).^[3] However, continuous use is not recommended without knowing an underlying condition.

Side effects

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

Hypersensitivity to naphazoline
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
A possible association with stroke has been suggested.^[4]

Nasal administration

Extended use may cause rhinitis medicamentosa, a condition of rebound nasal congestion.

Ophthalmic drug administration

Known side-effect:^[5]^[6]

Stinging
Discomfort
Irritation
Increased red eyes
Blurred vision
Mydriasis
Punctate keratitis
Lacrimation (tears)
Increased intraocular pressure

Contraindications

Patients taking MAO inhibitors can experience a severe hypertensive crisis if given a sympathomimetic drug such as naphazoline HCl
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.

Pharmacology

Naphazoline is a mixed α₁- and α₂-adrenergic receptor agonist.^[2]

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

It is an active ingredient in several over-the-counter eye drop formulations including Clear Eyes, Rohto Cool, Eucool, and Naphcon-A.^[7]

Illicit use

The nasal or ophthalmic form of naphazoline has been abused by heroin or cocaine drug addicts.^[8]^[9] It's used as CNS stimulant and vasoconstrictor to enhance primary drug effects.^[9]

References

↑ Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 552. ISBN 9783527607495.
1 2 3 Hosten LO, Snyder C (2020). "Over-the-Counter Ocular Decongestants in the United States - Mechanisms of Action and Clinical Utility for Management of Ocular Redness". Clinical Optometry. 12: 95–105. doi: 10.2147/OPTO.S259398 . PMC 7399465 . PMID 32801982.
↑ Yazulla S (September 2008). "Endocannabinoids in the retina: from marijuana to neuroprotection". Progress in Retinal and Eye Research. 27 (5): 501–526. doi:10.1016/j.preteyeres.2008.07.002. PMC 2584875 . PMID 18725316.
↑ 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): 889–891. doi: 10.1590/S0004-282X2004000500030 . PMID 15476091.
↑ "Naphazoline - FDA prescribing information, side effects and uses". Drugs.com.
↑ "naphazoline ophthalmic (eye): Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD". www.webmd.com.
↑ Green SM (2008). "Ophthalmology: Naphazoline". Tarascon Pocket Pharmacopoeia 2009. Jones and Bartlett. ISBN 978-0-7637-6572-9.
↑ van Montfrans GA, van Steenwijk RP, Vyth A, Borst C (1981). "Intravenous naphazoline intoxication". Acta Medica Scandinavica. 209 (5): 429–430. doi:10.1111/j.0954-6820.1981.tb11622.x. PMID 7246278.
1 2 "Naphazoline abuse". Reactions Weekly. 1815 (1): 251. 2020-08-01. doi:10.1007/s40278-020-81577-1. ISSN 1179-2051. S2CID 195174995.

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[Fis2006-1] Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 552. ISBN 9783527607495.

[pmid32801982-2] 1 2 3 Hosten LO, Snyder C (2020). "Over-the-Counter Ocular Decongestants in the United States - Mechanisms of Action and Clinical Utility for Management of Ocular Redness". Clinical Optometry. 12: 95–105. doi: 10.2147/OPTO.S259398 . PMC 7399465 . PMID 32801982.

[3] Yazulla S (September 2008). "Endocannabinoids in the retina: from marijuana to neuroprotection". Progress in Retinal and Eye Research. 27 (5): 501–526. doi:10.1016/j.preteyeres.2008.07.002. PMC 2584875 . PMID 18725316.

[pmid15476091-4] 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): 889–891. doi: 10.1590/S0004-282X2004000500030 . PMID 15476091.

[5] "Naphazoline - FDA prescribing information, side effects and uses". Drugs.com.

[6] "naphazoline ophthalmic (eye): Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD". www.webmd.com.

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

[8] van Montfrans GA, van Steenwijk RP, Vyth A, Borst C (1981). "Intravenous naphazoline intoxication". Acta Medica Scandinavica. 209 (5): 429–430. doi:10.1111/j.0954-6820.1981.tb11622.x. PMID 7246278.

[:0-9] 1 2 "Naphazoline abuse". Reactions Weekly. 1815 (1): 251. 2020-08-01. doi:10.1007/s40278-020-81577-1. ISSN 1179-2051. S2CID 195174995.

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v t e Phenethylamines
Phenethylamines	Psychedelics: 25B-NBOMe 25C-NBOMe 25D-NBOMe 25I-NBOMe 25N-NBOMe 2C-B 2C-B-AN 2C-Bn 2C-Bu 2C-C 2C-CN 2C-CP 2C-D 2C-E 2C-EF 2C-F 2C-G 2C-G-1 2C-G-2 2C-G-3 2C-G-4 2C-G-5 2C-G-6 2C-G-N 2C-H 2C-I 2C-iP 2C-N 2C-NH2 2C-O 2C-O-4 2C-P 2C-Ph 2C-SE 2C-T 2C-T-2 2C-T-3 2C-T-4 2C-T-5 2C-T-6 2C-T-7 2C-T-8 2C-T-9 2C-T-10 2C-T-11 2C-T-12 2C-T-13 2C-T-14 2C-T-15 2C-T-16 2C-T-17 2C-T-18 2C-T-19 2C-T-20 2C-T-21 2C-T-22 2C-T-22.5 2C-T-23 2C-T-24 2C-T-25 2C-T-27 2C-T-28 2C-T-30 2C-T-31 2C-T-32 2C-T-33 2C-TFE 2C-TFM 2C-YN 2C-V Allylescaline DESOXY Escaline Isoproscaline Jimscaline Macromerine MEPEA Mescaline Metaescaline Methallylescaline Proscaline Psi-2C-T-4 TCB-2 Stimulants: Phenylethanolamine Hordenine Phenethylamine Phenpromethamine α-Methylphenethylamine (amphetamine) β-Methylphenethylamine m-Methylphenethylamine N-Methylphenethylamine o-Methylphenethylamine p-Methylphenethylamine Methylphenidate Entactogens: Lophophine MDPEA MDMPEA Others: BOH DMPEA
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Phenylisobutylamines	Entactogens: 4-CAB 4-MAB Ariadne BDB Butylone EBDB Eutylone MBDB Stimulants: Phenylisobutylamine
Phenylalkylpyrrolidines	Stimulants: α-PBP α-PHP α-PPP α-PVP MDPBP MDPPP MDPV 4-MePBP 4-MePHP 4-MePPP MOPPP MOPVP MPBP MPHP MPPP Naphyrone PEP Prolintane Pyrovalerone
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Miscellaneous	AL-LAD Amidephrine Arbutamine Cafedrine Denopamine Desvenlafaxine Diphenidine Dizocilpine Dobutamine Dopexamine Ephenidine Etafedrine ETH-LAD Famprofazone Fluorolintane Hexapradol IP-LAD Lysergic acid amide Lysergic acid 2-butyl amide Lysergic acid 2,4-dimethylazetidide Lysergic acid diethylamide Methoxamine Methoxphenidine MT-45 PARGY-LAD Phenibut PRO-LAD Pronethalol Salbutamol (Levosalbutamol) Solriamfetol Theodrenaline Thiamphenicol UWA-101 Venlafaxine

Naphazoline

Contents

Medical uses

Nasal administration

Ophthalmic drug administration

Side effects

Nasal administration

Ophthalmic drug administration

Contraindications

Pharmacology

Chemistry

Society and culture

Illicit use

References