Introduction

Vasoconstrictor; an imidazoline-derivative sympathomimetic amine.

Uses for Tetrahydrozoline

Conjunctival Congestion

Temporary relief of conjunctival congestion, itching, and minor irritation.

Used alone or in fixed combination with astringents (i.e., zinc sulfate).

Controls hyperemia in patients with superficial corneal vascularity.

Ineffective in the treatment of delayed hypersensitivity reactions such as contact dermatoconjunctivitis.

Used for vasoconstrictor effect during some ocular diagnostic procedures; phenylephrine may be preferred.

Tetrahydrozoline Dosage and Administration

Administration

Ophthalmic Administration

Apply ophthalmic solution topically to the conjunctiva.

Remove contact lenses before administering ophthalmic solution; wait ≥15 minutes to reinsert contact lenses.

Do not administer discolored or cloudy solution.

Avoid contamination of the dropper tip.

Dosage

Available as tetrahydrozoline hydrochloride; dosage expressed in terms of the salt.

Pediatric Patients

Conjunctival Congestion

Ophthalmic

Children ≥6 years of age: 1–2 drops of a 0.05% ophthalmic solution in the affected eye(s) up to 4 times daily.

Adults

Conjunctival Congestion

Ophthalmic

1–2 drops of a 0.05% ophthalmic solution in the affected eye(s) up to 4 times daily.

Prescribing Limits

Pediatric Patients

Conjunctival Congestion

Ophthalmic

For self-medication: Maximum of 4 times daily; maximum duration of 3–4 days, unless directed by a clinician.

Adults

Conjunctival Congestion

Ophthalmic

For self-medication: Maximum of 4 times daily; maximum duration of 3–4 days, unless directed by a clinician.

Special Populations

No special population dosage recommendations at this time.

Contraindications

• Known hypersensitivity to tetrahydrozoline or any ingredient in the formulation.

Warnings/Precautions

Warnings

Glaucoma

Patients with narrow-angle glaucoma or other serious eye disease should consult a clinician before using ophthalmic solution.

General Precautions

Overuse

Possible irritation of conjunctiva and adverse systemic effects (particularly in children) with excessive dosage and/or prolonged or too frequent use. Possible ocular hyperemia (redness); avoid prolonged use. (See Advice to Patients.)

Overdose may produce CNS depression with drowsiness, decreased body temperature, bradycardia, shock-like hypotension, apnea, and coma.

Accidental ingestion of imidazoline derivatives (i.e., tetrahydrozoline, naphazoline, oxymetazoline) in children has resulted in serious adverse events requiring hospitalization (e.g., coma, bradycardia, decreased respiration, sedation, somnolence). (See Pediatric Use under Cautions and also see Advice to Patients.)

High concentrations of ophthalmic solution may liberate pigment granules; more common in the elderly.

Sympathomimetic Effects

Possible headache, hypertension, weakness, sweating, cardiac irregularities (e.g., palpitations), tremors, drowsiness, lightheadedness, and insomnia. Use with caution in patients with thyroid disease (e.g., hyperthyroidism), heart disease (e.g., coronary artery disease), hypertension, or diabetes mellitus.

Use of Fixed Combinations

When used in fixed combination with astringents (i.e., zinc sulfate), consider the cautions, precautions, and contraindications associated with the concomitant drug.

Specific Populations

Pregnancy

Category C.

Lactation

Not known whether tetrahydrozoline is distributed into milk. Caution if used in nursing women.

Pediatric Use

Safety and efficacy of ophthalmic solution not established in children <6 years of age.

Accidental ingestion of OTC ophthalmic solutions or nasal sprays containing imidazoline derivatives (i.e., tetrahydrozoline, naphazoline, oxymetazoline) in children has resulted in serious adverse events requiring hospitalization, including nausea, vomiting, lethargy, tachycardia, decreased respiration, bradycardia, hypotension, hypertension, sedation, somnolence, mydriasis, stupor, hypothermia, drooling, and coma. Respiratory depression, CNS depression, and/or lethargy reportedly occurred in infants following accidental ingestion of small amounts (≤6 mL) of 0.05% tetrahydrozoline ophthalmic solution. Keep out of reach of children. (See Advice to Patients.)

Common Adverse Effects

Ophthalmic: Blurred vision, irritation, mydriasis.

Administration

Ophthalmic Administration

Apply ophthalmic solution topically to the conjunctiva.

Remove contact lenses before administering ophthalmic solution; wait ≥15 minutes to reinsert contact lenses.

Do not administer discolored or cloudy solution.

Avoid contamination of the dropper tip.

Dosage

Available as tetrahydrozoline hydrochloride; dosage expressed in terms of the salt.

Pediatric Patients

Conjunctival Congestion

Ophthalmic

Children ≥6 years of age: 1–2 drops of a 0.05% ophthalmic solution in the affected eye(s) up to 4 times daily.

Adults

Conjunctival Congestion

Ophthalmic

1–2 drops of a 0.05% ophthalmic solution in the affected eye(s) up to 4 times daily.

Prescribing Limits

Pediatric Patients

Conjunctival Congestion

Ophthalmic

For self-medication: Maximum of 4 times daily; maximum duration of 3–4 days, unless directed by a clinician.

Adults

Conjunctival Congestion

Ophthalmic

For self-medication: Maximum of 4 times daily; maximum duration of 3–4 days, unless directed by a clinician.

Special Populations

No special population dosage recommendations at this time.