Drug information of Polymyxin N H
Mechanism of effect
Hydrocortisone: Decreases inflammation by suppression of migration of polymorphonuclear leukocytes and reversal of increased capillary permeability.
Neomycin: Interferes with bacterial protein synthesis by binding to 30S ribosomal subunits.
Polymyxin B: Binds to phospholipids, alters permeability, and damages the bacterial cytoplasmic membrane permitting leakage of intracellular constituents.
Polymyxin N.H is an antibiotic and anti-inflammatory drug. Polymyxin B binds to phospholipids, alters permeability and damages the bacterial cytoplasmic membrane permitting leakage intracellular constituents.
Pharmacokinetics: this drug is an otic drop without systemic absorption.
Adults: instill 4 drops three or four times a day.
Children: instill 3 drops into affected ear three or four times a day.
Therapy with this product should be limited to 10 consecutive days.
Drug contraindicationshypersensitivity to drug or its components.
Adrenal suppression: Systemic absorption of topical corticosteroids may cause hypercortisolism or suppression of hypothalamic-pituitary-adrenal (HPA) axis, particularly in younger children or in patients receiving high doses for prolonged periods. HPA axis suppression may lead to adrenal crisis.
- Immunosuppression: Prolonged use of corticosteroids may also increase the incidence of secondary infection, mask acute infection (including fungal infections), prolong or exacerbate viral infections, or limit response to vaccines.
- Kaposi sarcoma: Prolonged treatment with corticosteroids has been associated with the development of Kaposi sarcoma (case reports); if noted, discontinuation of therapy should be considered (Goedert, 2012).
- Neomycin sensitization: Neomycin may cause cutaneous sensitization. Symptoms of neomycin sensitization include itching, reddening, edema, and failure to heal. Discontinuation of product and avoidance of similar products should be considered.
- Ototoxicity: Neomycin may cause permanent sensorineural hearing loss due to cochlear damage. Risk of ototoxicity is increased in patients with extended use; limit therapy to 10 days. Do not use in any patient with a perforated tympanic membrane.
- Systemic effects: Topical corticosteroids may be absorbed percutaneously . Absorption of topical corticosteroids may cause manifestations of Cushing's syndrome, hyperglycemia, or glycosuria. Absorption is increased by the use of occlusive dressings, application to denuded skin, or application to large surface areas.
Neomycin can induce permanent sensorineural hearing loss due to cochlear damage, mainly destruction of hair cells in the organ of Corti . The risk is greater with prolonged use. Therapy should be limited to 10 consecutive days. Patients being treated with eardrops containing neomycin should be under close clinical observation. Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Suspension should not be used in any patient with a perforated tympanic membrane.
Discontinue promptly if sensitization or irritation occurs.
Neomycin sulfate may cause cutaneous sensitization. A precise incidence of hypersensitivity reactions (primarily skin rash) due to topical neomycin is not known.
When using neomycin-containing products to control secondary infection in the chronic dermatoses, such as chronic otitis externa or stasis dermatitis, it should be borne in mind that the skin in these conditions is more liable than is normal skin to become sensitized to many substances, including neomycin. The manifestation of sensitization to neomycin is usually a low-grade reddening with swelling, dry scaling, and itching; it may be manifested simply as a failure to heal.
Periodic examination for such signs is advisable, and the patient should be told to discontinue the product if they are observed. These symptoms regress quickly on withdrawing the medication. Neomycin-containing applications should be avoided for the patient thereafter.
As with other antibiotic preparations, prolonged use may result in overgrowth of nonsusceptible organisms, including fungi.
If the infection is not improved after 1 week, cultures and susceptibility tests should be repeated to verify the identity of the organism and to determine whether therapy should be changed.
Allergic cross-reactions may occur which could prevent the use of any or all of the following antibiotics for the treatment of future infections: kanamycin, paromomycin, streptomycin, and possibly gentamicin.
Points of recommendation
Avoid contaminating the bottle tip with material from the ear, fingers, or other source. This caution is necessary if the sterility of the drops is to be preserved.
If sensitization or irritation occurs, discontinue use immediately and contact your physician.
Therapy should be limited to 10 consecutive days.
Do not use in the eyes.
Shake well before using.
Ask a Pharmacist