Cortomycin
Classes
Ophthalmological Corticosteroid and Anti-infective Combinations
Topical Aminoglycosides, Plain or in Combination
Administration
Apply sparingly in a thin film to the affected area.
Do not cover with an occlusive dressing. A light gauze dressing may be used if required.
To avoid risk of infection, use one open tube per individual patient.
Do not apply topical skin ointment to eyes or ears.
For topical ophthalmic administration only.
Instruct patient on proper instillation of eye ointment.
Patients should not wear contact lenses if they have an ocular infection.
Do not to touch the tip of the applicator to the eye, eyelid, fingertips, or other surface.
Apply directly into the conjunctival sac. In blepharitis all scales and crusts should be carefully removed and the ointment then spread uniformly over the lid margins.
Keep tightly closed when not in use.
To avoid risk of infection, use one open tube per individual patient.
Adverse Reactions
hearing loss / Delayed / Incidence not known
skin atrophy / Delayed / Incidence not known
ocular hypertension / Delayed / Incidence not known
erythema / Early / 1.0-1.0
superinfection / Delayed / Incidence not known
impaired wound healing / Delayed / Incidence not known
contact dermatitis / Delayed / Incidence not known
cataracts / Delayed / Incidence not known
rash / Early / 1.0-1.0
pruritus / Rapid / 1.0-1.0
skin hypopigmentation / Delayed / Incidence not known
folliculitis / Delayed / Incidence not known
striae / Delayed / Incidence not known
miliaria / Delayed / Incidence not known
acneiform rash / Delayed / Incidence not known
xerosis / Delayed / Incidence not known
hypertrichosis / Delayed / Incidence not known
skin irritation / Early / Incidence not known
ocular pruritus / Rapid / Incidence not known
ocular irritation / Rapid / Incidence not known
Common Brand Names
AK-Spore HC, AK-Spore HC Ophthalmic, Cortisporin, Cortomycin, Neo-Polycin HC, Ocu-Cort
Dea Class
Rx
Description
Neomycin and polymyxin B affect primarily gram-negative, aerobic bacteria, while bacitracin is effective against gram-positive organisms; available in ophthalmic and topical forms.
Dosage And Indications
Apply a thin strip into the affected eye(s) every 3 to 4 hours, depending upon the severity of the infection. Use not more than 8 g or for longer than 10 days initially; the prescription should not be refilled without further evaluation.
Apply as a thin film topically to the affected area(s) 2 to 4 times per day. Therapy should be limited to 7 days.
Dosing Considerations
No dosage adjustment is needed.
Renal ImpairmentNo dosage adjustment is needed; use caution with prolonged therapy under conditions where systemic exposure is possible.
Drug Interactions
Amphotericin B lipid complex (ABLC): (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents, such as amphoteracin B; when possible, avoid concomitant administration. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, should not be given with other drugs that have a nephrotoxic potential.
Amphotericin B liposomal (LAmB): (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents, such as amphoteracin B; when possible, avoid concomitant administration. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, should not be given with other drugs that have a nephrotoxic potential.
Amphotericin B: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents, such as amphoteracin B; when possible, avoid concomitant administration. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, should not be given with other drugs that have a nephrotoxic potential.
Bumetanide: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
Ethacrynic Acid: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
Furosemide: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
Loop diuretics: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
Torsemide: (Minor) Additive nephrotoxicity may occur with concurrent use of systemic bacitracin and other nephrotoxic agents. When possible, avoid concomitant administration of systemic bacitracin and other nephrotoxic drugs such as loop diuretics. Topical administration of any preparation containing bacitracin, especially when applied to large surface areas, also should not be given with other drugs that have a nephrotoxic potential.
How Supplied
AK-Spore HC/AK-Spore HC Ophthalmic/Cortisporin/Cortomycin/Neomycin, Polymyxin B, Bacitracin Zinc, Hydrocortisone/Neo-Polycin HC/Ocu-Cort Ophthalmic Ointment
Cortisporin Topical Ointment
Maximum Dosage
8 g or 10 days for ophthalmic ointment then reevaluate before further therapy; 4 applications/day for up to 7 days topically.
Elderly8 g or 10 days for ophthalmic ointment then reevaluate before further therapy; 4 applications/day for up to 7 days topically.
AdolescentsSafety and efficacy have not been established.
ChildrenSafety and efficacy have not been established.
InfantsSafety and efficacy have not been established.
Mechanism Of Action
•Bacitracin: Bacitracin is primarily bacteriostatic, but may have bacteriocidal activity depending upon the antibiotic concentration and the susceptibility of the organism. Bacitracin inhibits bacterial cell wall formation. Bacitracin inhibits the final dephosphorylation step in the phospholipid carrier cycle, which inhibits mucopeptide transfer to the growing cell wall. Bacitracin is active against many gram-positive organisms and some gram-negative organisms.
•Hydrocortisone: The antiinflammatory activity of hydrocortisone is thought to involve phospholipase A2 inhibitory proteins, collectively called lipocortins. Lipocortins control the biosynthesis of potent mediators of inflammation, such as prostaglandins and leukotrienes, by inhibiting the release of the precursor molecule arachidonic acid.
•Neomycin: Neomycin is bacteriocidal. It inhibits bacterial protein synthesis through irreversible binding to the 30S ribosomal subunit of susceptible bacteria. Neomycin is actively transported into the bacterial cell where it binds to receptors present on the 30S ribosomal subunit. This binding interferes with the initiation complex between the messenger RNA (mRNA) and the subunit. As a result, abnormal, nonfunctional proteins are formed due to misreading of the bacterial DNA. Eventually, susceptible bacteria die because of the lack of functional proteins. Neomycin may also inhibit DNA polymerase.
•Polymyxin B: Polymyxin B binds to gram-negative bacterial cell membrane phospholipids. This binding destroys bacterial membranes with a surface detergent-like mechanism and increases the permeability of the cell membrane, which results in loss of metabolites essential to bacterial existence. Polymyxin B is bactericidal against most gram-negative bacilli; however, some Proteus and Serratia species may be resistant. Polymyxin B has no in vitro activity against gram-positive organisms.
Bacitracin, polymyxin B sulfate, and neomycin sulfate in combination are considered active against the following microorganisms: Enterobacter sp., Escherichia coli, Haemophilus influenzae, Klebsiella sp., Neisseria sp., Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus sp., including Streptococcus pneumoniae. These agents do not provide adequate coverage against Serratia marcescens.
Pharmacokinetics
Bacitracin; hydrocortisone; neomycin; polymyxin B combination products are applied topically to the eye or skin.
Topical RouteExcept when applied to large areas or for an extended period of time, systemic absorption of these agents is negligible after topical administration. Percutaneous penetration of hydrocortisone varies among individual patients and can be increased by the use of occlusive dressings, by increasing the concentration of the hydrocortisone, and by using different formulation vehicles. Topical preparations of hydrocortisone are primarily metabolized in the skin; systemic exposure is increased when there is breakdown of the skin barrier. Polymyxin B has a high affinity for cell membranes so there is little systemic absorption even when applied to open wounds. Bacitracin and neomycin may be absorbed systemically if applied to denuded or damaged epithelium. Any systemically absorbed bacitracin, polymyxin B, and neomycin are primarily excreted by the kidneys.
Pregnancy And Lactation
Bacitracin; hydrocortisone; neomycin; polymyxin B ophthalmic and topical products are classified as FDA pregnancy risk category C. Although systemic exposures of all 4 components are expected to be minimal, use of topical corticosteroids, such as hydrocortisone, have been shown to be teratogenic in animals. No adequate and well-controlled studies have been conducted in pregnant women, therefore this medication should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.
It is unknown if bacitracin, neomycin, or polymyxin B are excreted in breast milk; however, hydrocortisone does appear in human milk following oral administration. Therefore, bacitracin; hydrocortisone; neomycin; polymyxin B products should be used cautiously in nursing mothers even though systemic absorption following topical and ophthalmic application is negligible. To minimize potential infant exposure, instruct mothers not to apply the topical products directly to the breast during times of breast-feeding. If using the ophthalmic products, instruct patients to apply pressure over the tear duct by the corner of the eye for 1 minute after each administration. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, health care providers are encouraged to report the adverse effect to the FDA.