CORTISPORIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CORTISPORIN (CORTISPORIN).
Corticosteroid (hydrocortisone) suppresses inflammation by inhibiting phospholipase A2 and cytokine production; neomycin and polymyxin B are aminoglycoside and polypeptide antibiotics respectively, that inhibit bacterial protein synthesis and disrupt cell membrane integrity.
| Metabolism | Hydrocortisone is primarily metabolized in the liver via reduction and conjugation; neomycin is minimally metabolized; polymyxin B is not significantly metabolized. |
| Excretion | Cortisporin is a combination product containing neomycin, polymyxin B, and hydrocortisone. Neomycin is primarily excreted unchanged in urine via glomerular filtration (up to 80% of absorbed dose); polymyxin B undergoes renal excretion (60% unchanged in urine); hydrocortisone is metabolized in the liver and excreted as glucuronide and sulfate conjugates in urine (90%) and feces (10%). For otic and ophthalmic suspensions, systemic absorption is minimal, and excretion data reflect absorbed fractions. Overall, renal excretion accounts for >80% of absorbed drug; fecal/biliary elimination is negligible. |
| Half-life | Terminal elimination half-life for absorbed neomycin is approximately 2-3 hours in patients with normal renal function; polymyxin B has a half-life of 6-8 hours; hydrocortisone half-life is 1.5-2 hours. Clinically, the otic suspension is not intended for systemic effect; local drug levels persist at the site of application for several hours, but systemic half-life is relevant only if significant absorption occurs (e.g., inflamed tympanic membrane or prolonged use). |
| Protein binding | Neomycin: <10% bound to plasma proteins; polymyxin B: approximately 50% bound; hydrocortisone: 90-93% bound to corticosteroid-binding globulin and albumin. Systemically absorbed fractions are minimal in normal use. |
| Volume of Distribution | Neomycin Vd: 0.25 L/kg (primarily extracellular fluid); polymyxin B Vd: 0.8 L/kg (distributes widely to tissues, excluding CSF); hydrocortisone Vd: 0.2-0.3 L/kg (bound in plasma, limited extravascular distribution). For otic/ophthalmic use, Vd values reflect absorbed drug; clinical relevance is minimal due to low systemic absorption. |
| Bioavailability | Otic suspension: approximately 0.1-0.5% absorbed across intact tympanic membrane; may increase to 5-10% if eardrum is perforated or mucosa is inflamed. Ophthalmic suspension: less than 0.1% absorbed systemically; <1% via nasal lacrimal drainage. Bioavailability is negligible for intended local effect. |
| Onset of Action | Otic suspension: onset of anti-inflammatory effect occurs within 1-2 hours; antibacterial effect begins within 2-4 hours after application. Ophthalmic suspension: onset of anti-inflammatory effect within 1-2 hours; antimicrobial effect within 2-4 hours. Topical otic or ophthalmic routes achieve local therapeutic concentrations without significant systemic absorption. |
| Duration of Action | Otic suspension: therapeutic effect (anti-inflammatory and antimicrobial) lasts 6-8 hours per dose; recommended dosing every 6-8 hours. Ophthalmic suspension: duration 4-6 hours; dosing every 4-6 hours. Prolonged use may lead to local irritation or superinfection. |
Instill 3-4 drops into affected ear(s) 3-4 times daily. Do not use for more than 10 days.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for topical otic administration. |
| Liver impairment | No dosage adjustment required for topical otic administration. |
| Pediatric use | Children: Instill 3 drops into affected ear(s) 3-4 times daily. Safety and efficacy in infants <1 year not established. |
| Geriatric use | Same as adult dosing; no specific adjustment needed. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CORTISPORIN (CORTISPORIN).
| Breastfeeding | Systemic absorption from otic use is minimal. Neomycin, polymyxin B, and hydrocortisone are unlikely to be excreted into breast milk in significant amounts. No M/P ratio available. Considered compatible with breastfeeding when used as directed. |
| Teratogenic Risk | CORTISPORIN (neomycin/polymyxin B/hydrocortisone) otic suspension: Neomycin is an aminoglycoside that can cross the placenta; however, topical otic use results in negligible systemic absorption. No adequate and well-controlled studies in pregnant women. Animal studies with neomycin have shown potential for ototoxicity in offspring with high systemic doses. Polymyxin B is poorly absorbed systemically; no known teratogenic risk. Hydrocortisone: topical use at low concentrations has not been associated with teratogenicity in humans; risk of orofacial clefts with systemic corticosteroids in first trimester is low. Overall, due to minimal systemic absorption, risk is considered low. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to any component","Perforated tympanic membrane (relative, due to risk of ototoxicity)","Viral or fungal infections of the ear"]
| Precautions | ["Prolonged use may result in overgrowth of non-susceptible organisms including fungi","Systemic absorption of hydrocortisone may cause hypothalamic-pituitary-adrenal axis suppression","Neomycin may cause ototoxicity if used in perforated eardrum or prolonged use","Polymyxin B may cause nephrotoxicity if absorbed systemically"] |
Loading safety data…
| Fetal Monitoring | No specific monitoring required for topical otic use. In case of prolonged or excessive use, monitor for signs of maternal ototoxicity or nephrotoxicity (neomycin) and adrenal suppression (hydrocortisone). |
| Fertility Effects | No known effects on fertility from topical otic use. |