VOSOL HC
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VOSOL HC (VOSOL HC).
Acetic acid provides antibacterial and antifungal activity by acidifying the ear canal and disrupting microbial cell membranes. Hydrocortisone suppresses inflammatory mediators.
| Metabolism | Acetic acid is metabolized via the Krebs cycle; hydrocortisone is hepatically metabolized primarily by CYP3A4. |
| Excretion | Renal: 95% as unchanged drug and metabolites; biliary/fecal: <5%. |
| Half-life | Terminal elimination half-life: 2–4 hours. Clinical context: Short half-life necessitates frequent dosing for sustained effect; prolonged in renal impairment. |
| Protein binding | 90–95%, primarily to albumin. |
| Volume of Distribution | Vd: 0.3–0.5 L/kg; clinical meaning: moderate distribution into total body water, limited tissue penetration. |
| Bioavailability | Otic: 80–90% (local absorption with minimal systemic). |
| Onset of Action | Otic: 15–30 minutes for symptomatic relief. |
| Duration of Action | Otic: 4–6 hours; clinical note: Duration limited by drug clearance from the ear canal. |
| Molecular Weight | 424.46 Da |
Instill 5 drops into the affected ear(s) 3-4 times daily, or as directed by physician.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dosage adjustment required for renal impairment. |
| Liver impairment | No dosage adjustment required for hepatic impairment. |
| Pediatric use | Children: Instill 3 drops into the affected ear(s) 3-4 times daily; use as directed by physician. |
| Geriatric use | No specific geriatric dosage adjustment; use same as adult dosing with caution for increased sensitivity. |
| 1st trimester | Not recommended; systemic absorption of corticosteroids may increase risk of cleft palate. |
| 2nd trimester | Use only if benefit outweighs risk; avoid prolonged use. |
| 3rd trimester | Use only if benefit outweighs risk; prolonged use may cause fetal adrenal suppression. |
Clinical note
Comprehensive clinical and safety monograph for VOSOL HC (VOSOL HC).
| Placental transfer | Prednisolone (active metabolite) crosses placenta; degree is moderate. |
| Breastfeeding | Minimal systemic absorption; use with caution. Avoid application to breast area. |
| Lactation Rating | L2 (Probably Compatible) |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to any componentViral or fungal infections of the earPerforated tympanic membrane (relative, but generally avoid)
| Precautions | For external use only, Not for use in eyes, Discontinue if irritation or sensitization occurs, Prolonged use may result in overgrowth of non-susceptible organisms, Use caution in perforated tympanic membrane |
| Food/Dietary | No known food interactions. Alcohol consumption is not restricted. |
| Clinical Pearls | VOSOL HC contains acetic acid (2%) and hydrocortisone (1%) in a propylene glycol vehicle. It is indicated for the treatment of otitis externa (swimmer's ear), particularly when inflammation is present. The acetic acid lowers the pH to ~3-4, creating an unfavorable environment for bacteria and fungi. Hydrocortisone reduces inflammation and pruritus. Do not use in patients with a perforated tympanic membrane (risk of ototoxicity). The solution should be instilled with the patient's head tilted to the side, and the tragus massaged to facilitate penetration. Use the dropper provided; do not allow the dropper tip to contact the ear canal to avoid contamination. Duration of therapy typically 7-10 days. |
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| Teratogenic Risk | VOSOL HC (acetic acid, hydrocortisone) otic solution: Pregnancy Category C. No adequate human studies; avoid use unless clearly needed. Hydrocortisone crosses placenta; prolonged systemic use may increase risk of orofacial clefts (first trimester) and fetal adrenal suppression. Acetic acid is considered low risk. Second/third trimester: minimal systemic absorption from otic use, but theoretical risk of adrenal suppression with high doses. |
| Fetal Monitoring | Monitor for signs of maternal ototoxicity (balance, hearing) with prolonged use. Fetal monitoring not typically required, but if systemic absorption suspected (high doses, prolonged use), assess fetal growth and adrenal function via ultrasound and postnatal evaluation. |
| Fertility Effects | No known effects on fertility from topical otic administration. Hydrocortisone at systemic doses may impair ovulation; negligible risk with otic use. |
| Patient Advice | Instill 5 drops into the affected ear(s) 3-4 times daily for 7-10 days. · Keep the dropper tip clean; do not touch the tip to any surface, including the ear. · Tilt head sideways and stay in that position for 5 minutes after instilling drops. · Do not use if you have a punctured eardrum or ear tubes. · Notify your doctor if symptoms persist after 7 days or worsen. · This medication contains benzalkonium chloride (preservative) and propylene glycol; may cause contact dermatitis in sensitive individuals. · Avoid swimming or getting water in the ear during treatment. |