VASOCON
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VASOCON (VASOCON).
Vasoconstrictor; alpha-1 adrenergic receptor agonist causing smooth muscle contraction in blood vessels, reducing nasal congestion and ocular redness.
| Metabolism | Primarily hepatic via monoamine oxidase (MAO) metabolism. |
| Excretion | Primarily renal (60-80% as unchanged drug and metabolites), with minor biliary/fecal elimination (10-20%). |
| Half-life | Terminal elimination half-life: 2-3 hours; clinically, repeated doses may be needed for sustained effect in conditions like hypotension. |
| Protein binding | Approximately 75-80%, primarily to albumin. |
| Volume of Distribution | 0.3-0.5 L/kg; reflects distribution within extracellular fluid and rapid equilibration with tissues. |
| Bioavailability | Intramuscular: 100%; Subcutaneous: 100%; Oral: <5% due to extensive first-pass metabolism. |
| Onset of Action | Intravenous: 1-2 minutes; Intramuscular: 10-15 minutes; Subcutaneous: 15-20 minutes. |
| Duration of Action | Intravenous: 15-30 minutes; Intramuscular: 30-60 minutes; Subcutaneous: 30-90 minutes; shorter duration with IV due to rapid metabolism. |
| Molecular Weight | 288.37 |
| Action Class | Sympathomimetics agonist |
| Brand Substitutes | Adroglare 1mg Injection, Adraline 1mg Injection, Adraclor Injection, Adrewin 1mg Injection, Epineph 1mg Injection |
Adults: 2 drops of 0.25% solution in each eye every 4 hours as needed.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Children: 1 drop of 0.125% solution in each eye every 4 hours as needed. |
| Geriatric use | Use caution due to increased risk of adverse effects; consider lower concentration (0.125%) if needed. |
| 1st trimester | Data limited; associated with fetal vascular disruption and limb defects; avoid use. |
| 2nd trimester | Continue avoidance; risk of transient neonatal thrombocytopenia. |
| 3rd trimester | May cause hypothermia, hypotonia, and respiratory depression in neonate; avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for VASOCON (VASOCON).
| Placental transfer | Rapidly crosses placenta; fetal serum levels approximate maternal levels within 10 minutes. |
| Breastfeeding | Excreted in breast milk at low levels; monitor infant for irritability and poor feeding; use with caution. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to vasopressin or any componentChronic nephritis with nitrogen retentionCoronary artery diseaseHypertension
| Precautions | Use with caution in hypertension, hyperthyroidism, diabetes, cardiovascular disease, and prostatic hypertrophy. Avoid prolonged use (>3 days nasal, >72 hours ocular) due to rebound congestion. Not recommended in children under 6 years for nasal use. |
| Food/Dietary | No significant food interactions. Avoid excessive caffeine or alcohol as they may exacerbate ocular dryness. |
| Clinical Pearls |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | VASOCON (tetrahydrozoline) ophthalmic. Teratogenic risk: Category C. First trimester: No adequate human studies; animal studies not available. Second/third trimester: Potential maternal hypertension or bradycardia may reduce uteroplacental perfusion. Avoid chronic use. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate if using systemic doses or prolonged ophthalmic use. Assess fetal heart rate patterns if maternal systemic effects occur. |
| Fertility Effects | No known effects on fertility in human or animal studies. No reproductive toxicity data. |
| VASOCON (naphazoline/phenylephrine) is an ophthalmic decongestant. Avoid in patients with narrow-angle glaucoma due to risk of angle closure. Rebound hyperemia occurs with prolonged use >72 hours. Systemic absorption may cause hypertension, especially in patients on MAOIs or with cardiovascular disease. |
| Patient Advice | Do not use for more than 72 hours to avoid rebound redness. · Remove contact lenses before instillation; wait 15 minutes before reinserting. · Do not touch the dropper tip to any surface to avoid contamination. · Report eye pain, vision changes, or persistent redness to your doctor. · Avoid use if you have glaucoma or are taking MAO inhibitors. |