TetrahydrozolineMatthew G. Cordes Huntington VA Medical Center, Huntington, USA

ã 2007 Elsevier Inc. All rights reserved.

Introduction

Tetrahydrozoline is an alpha adrenoceptor agonist formulated as a 0.05% topical oph-thalmic decongestant for the relief of ocular erythema, irritation, and conjunctival edemafrom allergic conjunctivitis, conjunctivitis, and minor inflammatory conditions of the eye.

NomenclatureName of the Clinical

Form

Tetrahydrozoline

Related Names

Source: EMTREE

Tetrahydrozoline; murine plus; nasan; nazane; nazine; necor

tyzine; rhinopront; rhinoprout; 2 (1,2,3,4 tetrahydro

1naphthyl)imidazoline; 2 (1,2,3,4 tetrahydro 1 naphthyl)

imidazoline hydrochloride; tetrahydrozoline hydrochloride;

tetryzolin; tetryzoline hydrochloride; tyzanol; tyzine; visine;

tacrine; tetryzoline; 2 (1,2,3,4 tetrahydro 1 naphthyl)

imidazoline

Chemical Names 2-Imidazoline, 2-(1,2,3,4-tetrahydro-1-naphthyl)-

CAS Number 84-22-0

Basic ChemistryChemical Structure

Structure

Chemical

Formula

C13 H16 N2

Properties

Physical

Properties

White, odorless, crystalline powder

Molecular

Weight

200.283

Solubility Tetrahydrozoline is freely soluble in water and alcohol, slightly soluble

in chloroform, and insoluble in ether and benzene.

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Human Pharmacokinetics

The onset of action of topically applied tetrahydrozoline is 5 to 10 minutes, with its effectslasting for up to eight hours. While topical ophthalmic tetrahydrozoline is absorbedthrough the nasolacrimal duct and the nasal mucosa, its systemic absorption is minimal.

Targets-Pharmacodynamics

With topical ophthalmic instillation, tetrahydrozoline causes constriction of arterioles andcapillaries, thereby reducing hyperemia and leakage of fluid.

Target Name(s):

Alpha adrenoceptors

Therapeutics

Tetrahydrozoline is used for the temporary relief of the redness and swelling associatedwith allergic conjunctivitis.

Indications

Value Units

Prep. andRoute ofAdmin. Reference Comments

Allergic conjunctivitis; conjunctivitisDosage 1–2 drops up to 4 times daily

of 0.05% topical

sterile ophthalmic

solution

Product Information

Visine (1995)

Tetrahydrozoline

ophthalmic drops

should generally not be

used for more than 3–5consecutive days.

Contraindications

Tetrahydrolozine is contraindicated in those known to be hypersensitive to it or otheradrenergic agents, or who have narrow angle glaucoma. It should not be used whilewearing contact lenses. Tetrahydrolozine should be used with caution in patients withcardiovascular disease, who are taking monoamine oxidase inhibitors or tricyclic anti-depressants, with diabetics, those with hypertension, an enlarged prostate, or thyroiddisease.

Adverse Effects

Tetrahydrolozine may cause ocular burning, stinging, dryness, headache, insomnia, dizzi-ness, tremors, palpitations, rebound erythema and congestion. Its use in greater thanrecommended doses may cause hypertension, bradycardia, rebound hypotension, andpossibly arrhythmias. Prolonged use may cause rebound vasodilation, congestion, andrhinitis medicamentosa.

Tetrahydrozoline2

Agent-Agent Interactions

Agent Name Mode of Interaction

Furazolidone May increase in the alpha adrenergic effects of tetrahydrozoline and other

sympathomimetics by inhibition of monoamine oxidase.

IsocarboxazidWhen given in combination with tetrahydrolozine, isocarboxazid can cause severeheadaches and hypertensive crises. Other potential reactions include nausea,

vomiting, cardiac arrhythmias, chest pain, intracranial bleeding, circulatory failure,

hyperpyrexia, and death.

Procarbazine As a monoamine oxidase inhibitor, procarbazine, in combination with tetrahydrozoline,may cause hypertension, including hypertensive crisis.

Other Information – Web Sites

Micromedex (2001) – Tetrahydrozoline, pp. 114: http://www.nlm.nih.gov/medlineplus/micromedexdisclaimer.html

Book Citations

Product Information Visine 1995 VisineW. Pfizer.

Further Reading

Drug Interaction Facts, D. S. Tatro (Ed.), J. B. Lippincott, St. Louis, MO, 1988

Tetrahydrozoline 3