Ketonate

Uses

Treatment of superficial and deep mycoses:

• Infections of the skin, hair and nails by dermatophytes and/or yeasts (dermatomycosis, onychomycosis, perionyxis, pityriasis versicolor, chronic mucocutaneous candidiasis etc.) especially when topical treatment is difficult or not very effective, owing to involvement of large skin surfaces or to lesions affecting deeper dermal layers, nails and hairs
• Yeast infection of the mouth (oral thrush, perleche) and the gastrointestinal tract
• Vaginal candidiasis, especially chronic recurrent cases or cases responding poorly to topcial treatment
• Systemic mycotic infections such as systemic candidiasis, paracoccidioidomycosis, histoplasmosis, coccidioidomycosis etc.

Maintenance treatment to prevent recurrence in systemic mycotic infections and in chronic mucocutaneous candidiasis.Prophylactic treatment to prevent mycotic infection in patients with reduced host defenses, e.g., patients with cancer, organ transplant and burns.

Neomycin is an aminoglycoside antibiotic agent used orally and topically to treat a wide variety of infections in the body.

Oral neomycin sulfate is indicated as an adjunctive therapy in hepatic coma (portal-system encephalopathy) by reducing ammonia-forming bacteria in the intestinal tract. It is strongly recommended that oral neomycin is only used in infections that are proven or strongly suspected to be caused by susceptible bacteria to reduce the risk of the development of drug-resistant bacteria.

Neomycin, in combination with polymyxin B sulfates and hydrocortisone in otic suspensions, is used in the treatment of superficial bacterial infections of the external auditory canal caused by organisms susceptible to the antibiotics. This otic formulation is also used in the treatment of infections of mastoidectomy and fenestration cavities caused by organisms susceptible to the antibiotics.

The ophthalmic solution containing neomycin in combination with polymyxin B sulfates and dexamethasone is used to treat steroid-responsive inflammatory ocular conditions for which a corticosteroid is indicated and where bacterial infection or a risk of bacterial infection exists.

Ketonate is also used to associated treatment for these conditions: Bacterial Vaginosis (BV), Blastomycosis, Candidiasis, Systemic, Chromomycosis, Chronic Mucocutaneous Candidiasis (CMC), Coccidioidomycosis, Dandruff, Endogenous Cushing's Syndrome, Histoplasmosis, Infections, Fungal, Paracoccidioidomycosis, Seborrheic Dermatitis, Tinea Corporis caused by Epidermophyton floccosumin, Tinea Corporis caused by Trichophyton mentagrophytes, Tinea Corporis caused by Trichophyton rubrum, Tinea Cruris caused by Epidermophyton floccosumin, Tinea Cruris caused by Trichophyton mentagrophytes, Tinea Cruris caused by Trichophyton rubrum, Tinea Pedis caused by Epidermophyton floccosumin, Tinea Pedis caused by Trichophyton mentagrophytes, Tinea Pedis caused by Trichophyton rubrum, Vaginal Candidiasis, Vulvovaginal Candidiasis, Cutaneous candidiasis, Recalcitrant Dermatophytosis, Tinea versicolor caused by Malassezia infectionAcne pustular, Allergic Contact Dermatitis, Allergy Skin, Atopic Dermatitis (AD), Atopic Dermatitis (AD) of the external ear canal, Bacterial diarrhoea, Burns, Carbuncle, Cradle Cap, Dermatitis, Dermatitis, Contact, Dermatitis, Eczematous, Diarrhoea, Discoid Lupus Erythematosus (DLE), Ear infection bacterial, Ear infection bacterial caused by susceptible bacteria, Gastrointestinal Infections, Hepatic coma, Hidradenitis Suppurativa (HS), Hot Water Burns (Scalds), Impetigo, Impetigo contagious, Infantile Eczema, Infected Wounds, Infected skin ulcer, Infection of the outer ear caused by susceptible bacteria, Infectious diarrhea, Inflammatory Reaction caused by Acne, Intertrigo, Itching caused by Infection, Lichen Planus (LP), Localized Infection caused by susceptible bacteria, Nail infection, Neurodermatitis, Otitis Externa, Postoperative Wound Infection, Psoriasis Vulgaris (Plaque Psoriasis), Pustular Dermatosis, Radiodermatitis, Secondarily Infected Eczema, Secondary Bacterial Infection, Skin Burns, Skin Infections, Skin Infections, Bacterial, Skin Irritation, Skin Ulcer, Solar erythema, Abrasions, Blistering caused by Staphylococcus, Erythematous eruptions, Intertriginous erythema of the anogenital, Ocular bacterial infections caused by susceptible bacteria, Resistant to other corticosteroids Dermatosis, Susceptible Bacterial Infections

How Ketonate works

Ketoconazole interacts with 14-α-sterol demethylase, a cytochrome P-450 enzyme necessary for the conversion of lanosterol to ergosterol. This results in inhibition of ergosterol synthesis and increased fungal cellular permeability due to reduced amounts of ergosterol present in the fungal cell membrane. This metabolic inhibition also results in accumulation of 14α-methyl-3,6-diol, a toxic metabolite. The increase in membrane fluidity is also thought to produce impairment of membrane-bound enzyme systems as components become less closely packed.

Like other aminoglycoside antibiotic drugs, neomycin inhibits bacterial ribosomes by binding to the 30S ribosomal subunit of susceptible bacteria and disrupting the translational machinery of bacterial protein synthesis. Bacterial translation is normally initiated by the mRNA binding to the 30S ribosomal subunit and subsequent binding with 50S subunit for elongation.

Dosage

Ketonate dosage

Oral-

Fungal infections:

• Adult: 200 mg once daily; may increase to 400 mg once daily if clinical response is insufficient. Continue treatment until symptoms have cleared and cultures have become negative.
• Child: ≥2 yr 3.3-6.6 mg/kg once daily. Treatment duration: 1-2 wk for candidiasis; at least 4 wk in recalcitrant dermatophyte infections and up to 6 mth for other systemic mycoses.
• Elderly: No dosage adjustment needed.

Topical (Adult)-

Pityriasis versicolor, Skin fungal infections:

• As 2% cream: Apply 1-2 times daily to cover affected and surrounding area until at least a few days after disappearance of symptoms.
• As 2% shampoo: Apply on scalp once daily for up to 5 days. For prophylaxis: As 2% shampoo, use once daily for a max of 3 days before exposure to sunlight.

Seborrhoeic dermatitis:

• As 2% foam: Apply to the affected area bid for 4 wk.
• As 1 or 2% shampoo: Apply on the scalp twice wkly for 2-4 wk. For prophylaxis: As 2% shampoo, use once every 1-2 wk.

Duration of Treatment

• Pityriasis versicolor: 1 to 6 weeks
• Dermatomycoses: 2 to 8 weeks
• Onychomycoses: 1 to 12 months
• Mycoses of hair and scalp: 1 to 2 months
• Chronic mucocutaneous candidiasis : 1 to 12 months
• Oral mycoses: 5 to 10 days
• Systemic candidiasis: 1 to 2 months
• Paracoccidioidomycosis,histoplasmosis
• and other systemic mycosis: 1 month to 2 years

Side Effects

Ketoconazole is very well tolerated. Nausea and itching may occasionally occur. In some patients, an idosyncratic liver reaction may occur (incidence 1 : 10,000).

Toxicity

Symptoms of overdose include acute liver injury, which may include both hepatocellular and cholestatic injury, accompanied by anorexia, fatigue, nausea, and jaundice. In case of overdose, gastric lavage with activated charcoal may be used if within one hour of ketoconazole ingestion otherwise provide supportive care. If the patient shows signs of adrenal insufficiency, administer 100 mg hydrocortisone once together with saline and glucose infusion and monitor the patient closely. Blood pressure and fluid and electrolyte balance should be monitored over the next few days.

The oral LD₅₀ of neomycin sulfate in mouse is > 8 g/kg. The subcutaneous LD₅₀ is 200 mg/kg in rat and 190 mg/kg in mouse. The intraperitoneal LD₅₀ in mouse is 305 mg/kg. The oral Lowest published toxic dose (TDLo) in woman is 12600 mg/kg/7D.

Because of low absorption, acute overdosage from oral neomycin is not likely to occur. However, prolonged administration of neomycin should be avoided because of the possibility of some systemic absorption and the risk of neurotoxicity, ototoxicity, and/or nephrotoxicity. Hemodialysis will remove neomycin from the blood. While nephrotoxicity and ototoxicity have been reported in otherwise patients without compromised renal function, the risk for developing these toxicities is increased in patients with renal impairment. Like other aminoglycosides, neomycin may cause fetal harm and total irreversible bilateral congenital deafness when administered in pregnant women.

Precaution

Predisposition to adrenocortical insufficiency. Admin with acidic drink in patients with achlorhydria. Pregnancy and lactation.

Interaction

Reduced absorption with antimuscarinics, antacids, H2-blockers, PPIs and sucralfate. Reduced plasma concentrations with rifampicin, isoniazid, efavirenz, nevirapine, phenytoin. May also reduce concentrations of isoniazid and rifampicin. May reduce efficacy of oral contraceptives. May increase serum levels of CYP3A4 substrates e.g. digoxin, oral anticoagulants, sildenafil, tacrolimus.

Volume of Distribution

Ketoconazole has an estimated volume of distribution of 25.41 L or 0.36 L/kg. It distributes widely among the tissues, reaching effective concentrations in the skin, tendons, tears, and saliva. Distribution to vaginal tissue produces concentrations 2.4 times lower than plasma. Penetration into the CNS, bone, and seminal fluid are minimal. Ketoconazole has been found to enter the breast milk and cross the placenta in animal studies.

The small fraction of absorbed neomycin is rapidly distributed in the tissues. The amount of systemically absorbed neomycin is reported to increase cumulatively with each repeated dose administered until a steady state is reached.

Elimination Route

Ketoconazole requires an acidic environment to become soluble in water. At pH values above 3 it becomes increasingly insoluble with about 10% entering solution in 1 h. At pH less than 3 dissolution is 85% complete in 5 min and entirely complete within 30 min. A single 200 mg oral dose produces a Cmax of 2.5-3 mcg/mL with a Tmax of 1-4 h. Administering ketoconazole with food consistently increases Cmax and delays Tmax but literature is contradictory regarding the effect on AUC, which may experience a small decrease. A bioavailablity of 76% has been reported for ketoconazole.

Neomycin is poorly absorbed from the gastrointestinal tract. Gastrointestinal absorption of the drug may be increased if inflammatory or ulcerative gastrointestinal disease is present.

Half Life

Ketoconazole experiences biphasic elimination with the first phase having a half-life of 2 hours and a terminal half life of 8 hours.

There is limited information on the half-life of neomycin.

Clearance

Ketoconazole has an estimated clearance of 8.66 L/h.

There is limited information on the clearance rate of neomycin.

Elimination Route

Only 2-4% of the ketoconazole dose is eliminated unchanged in the urine. Over 95% is eliminated through hepatic metabolism.

The small absorbed fraction of neomycin is excreted by the kidney. The unabsorbed portion of the drug is excreted unchanged in the feces.

Pregnancy & Breastfeeding use

Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.

Contraindication

Hypersensitivity; preexisting liver disease. Concurrent use with CYP3A4 substrates e.g. HMG-CoA reductase inhibitors (e.g. lovastatin, simvastatin), midazolam, triazolam, cisapride, dofetilide, eplerenone, nisoldipine, pimozide, quinidine, terfenadine, astemizole, ergot alkaloids (e.g. ergotamine, dihydroergotamine).

Special Warning

Renal Impairment: Oral: No dosage adjustment needed.

Hepatic Impairment: Oral: Contraindicated.

Storage Condition

Store between 15-25° C. Protect from moisture and light.

Innovators Monograph

You find simplified version here Ketonate