Naphazoline
| Systematic (IUPAC) name | |
|---|---|
| 2-(naphthalen-1-ylmethyl)-4,5-dihydro-1H-imidazole | |
| Clinical data | |
| Trade names | Naphcon-a |
| AHFS/Drugs.com | monograph |
| Pregnancy cat. | ? |
| Legal status | ? |
| Routes | Topical |
| Identifiers | |
| CAS number | 835-31-4 |
| ATC code | R01AA08 |
| PubChem | CID 4436 |
| DrugBank | DB06711 |
| ChemSpider | 4283 |
| UNII | H231GF11BV |
| KEGG | D08253 |
| ChEMBL | CHEMBL761 |
| Chemical data | |
| Formula | C14H14N2 |
| Mol. mass | 210.274 |
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Naphazoline (in the hydrochloride form) is the common name for 2-(1-naphthylmethyl)-2-imidazoline hydrochloride. 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 is an active ingredient in several over-the-counter formulations including Clear Eyes and Naphcon eye drops.[1]
It has the molecular formula C14H14N2.HCl and a molecular weight of 246.73 g/mol.
Warnings and contraindications [edit]
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 arrythmia 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]
Chemistry [edit]
Naphazoline, 2-(1-naphthylmethyl)-2-imidazoline, is synthesized from (1-naphthyl)acetonitrile, which upon reaction with ethanol transforms into iminoester, and undergoes further heterocyclization into the desired imidazoline derivative upon reaction with ethylene diamine ![]()
- A. Sonn, U.S. Patent 2,161,938 (1939).
References [edit]
- ^ "Ophthalmology: naphazoline". Tarascon Pocket Pharmacopoeia 2009. Jones and Bartlett Publishers. 2008. ISBN 0-7637-6572-4.
- ^ Zavala JA, Pereira ER, Zétola VH, Teive HA, Nóvak EM, Werneck LC (September 2004). "Hemorrhagic stroke after naphazoline exposition: case report". Arq Neuropsiquiatr 62 (3B): 889–91. PMID 15476091.
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