TYZINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TYZINE (TYZINE).
Imidazoline sympathomimetic amine that stimulates alpha-2 adrenergic receptors in the nasal vasculature, producing vasoconstriction and reducing nasal congestion.
| Metabolism | Primarily hepatic metabolism via oxidation and reduction pathways; no specific CYP enzymes identified. |
| Excretion | Renal elimination of unchanged drug and metabolites accounts for approximately 50% of the dose; fecal elimination is minimal. |
| Half-life | Terminal elimination half-life is approximately 3-4 hours; clinically, this supports dosing every 8-12 hours. |
| Protein binding | Approximately 50% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 1.5 L/kg, indicating extensive tissue distribution beyond plasma volume. |
| Bioavailability | Intranasal: approximately 100% (local effect); systemic bioavailability is low due to local vasoconstriction limiting absorption. |
| Onset of Action | Intranasal: within 1-2 minutes. |
| Duration of Action | Intranasal: 4-6 hours; repeated use may lead to tachyphylaxis. |
| Molecular Weight | 200.28 |
Instill 1-2 drops of 0.1% solution into each nostril every 4-6 hours as needed; not to exceed 4 doses per day.
| Dosage form | SOLUTION |
| Renal impairment | No dose adjustment required. |
| Liver impairment | No dose adjustment required. |
| Pediatric use | Children 6-12 years: Instill 1-2 drops of 0.05% solution into each nostril every 4-6 hours as needed; not to exceed 4 doses per day. For children under 6: Not recommended. |
| Geriatric use | Use with caution due to increased sensitivity and risk of adverse effects; consider lower concentration (0.05%) and limit duration of use to 3-5 days. |
| 1st trimester | Avoid use during first trimester due to potential vasoconstrictive effects and lack of safety data. |
| 2nd trimester | Use only if clearly needed; may cause maternal hypertension and reduced placental perfusion. |
| 3rd trimester | Avoid near term due to risk of uterine hypertonus and fetal hypoxia. |
Clinical note
Comprehensive clinical and safety monograph for TYZINE (TYZINE).
| Placental transfer | Unknown; however, due to low systemic absorption from intranasal use, placental transfer is likely minimal but not studied. |
| Breastfeeding | Intranasal decongestants like tetrahydrozoline are minimally absorbed systemically, but due to lack of data, avoid use during breastfeeding, especially in neonates. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Angle-closure glaucomaRhinitis siccaHypersensitivity to tetrahydrozoline or any component
| Precautions | Rebound congestion (rhinitis medicamentosa) with prolonged use, Potential for systemic effects with excessive use (hypertension, palpitations), Use caution in cardiovascular disease, hypertension, hyperthyroidism, diabetes, and glaucoma |
| Food/Dietary | None known. No specific dietary restrictions. |
| Clinical Pearls | Tyzine (tetrahydrozoline) is an imidazoline derivative with alpha-adrenergic agonist activity. It causes vasoconstriction of conjunctival blood vessels but may produce rebound hyperemia, mydriasis, and systemic effects if overused. Avoid in narrow-angle glaucoma. Use with caution in patients with hypertension, cardiovascular disease, hyperthyroidism, or diabetes. Do not use longer than 72 hours to prevent rebound congestion. Contact lens wearers should remove lenses before instillation. Do not use in patients with MAOI therapy or within 14 days of discontinuation. |
Loading safety data…
| L3 (Limited Data) |
| Teratogenic Risk | Limited human data; animal studies not conducted. Inadequate evidence for first trimester risk. Avoid during entire pregnancy unless clearly needed. Second and third trimester: no known teratogenicity but risk of maternal hypertension and reduced placental perfusion. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate due to potential hypertensive effect. Fetal heart rate monitoring if used near term. Assess uterine activity if used intranasally for prolonged duration. |
| Fertility Effects | No data on effect on fertility. Alpha-adrenergic agonists may theoretically impair fallopian tube transport or uterine blood flow. No known direct impact on gamete function. |
| Patient Advice | Do not use more than the recommended dose or for longer than 3 days. · Remove contact lenses before using drops and wait at least 15 minutes before reinserting. · Avoid touching the dropper tip to any surface to prevent contamination. · Do not share the medication with others. · If you experience eye pain, vision changes, or redness lasting >72 hours, stop use and consult a doctor. · Do not use if pregnant or breastfeeding without medical advice. · Keep out of reach of children; accidental ingestion may cause serious side effects. |