Itraconazole

Absorption

The absolute oral bioavailability of itraconazole is 55%, and is maximal when taken with a full meal.

Toxicity

No significant lethality was observed when itraconazole was administered orally to mice and rats at dosage levels of 320 mg/kg or to dogs at 200 mg/kg.

Description

Itraconazole is an orally-active triazole antifungal indicated for use in the treatment of dermal, vaginal and systemic mycoses. In immunocompromised and AIDS patients, itraconazole has been shown to significantly reduce the incidence of relapses of cryptococcal meningitis.

The Uses of Itraconazole

Itraconazole is a triazole antifungal agent. It is used to inhibit cytochrome P-450-dependent enzymes and ergosterol synthesis. It has been used against histoplasmosis, blastomycosis, cryptococcal meningitis, and aspergillosis. It?s different formulations are used to study Candida strains in murine invasive infections. It has been used to study proliferative changes of the forestomach mucosa in alloxan-induced diabetic rats..

Background

One of the triazole antifungal agents that inhibits cytochrome P-450-dependent enzymes resulting in impairment of ergosterol synthesis. It has been used against histoplasmosis, blastomycosis, cryptococcal meningitis & aspergillosis.

Indications

For the treatment of the following fungal infections in immunocompromised and non-immunocompromised patients: pulmonary and extrapulmonary blastomycosis, histoplasmosis, aspergillosis, and onychomycosis.

What are the applications of Application

Itraconazole is a triazole antifungal agent

Pharmacokinetics

Itraconazole is an imidazole/triazole type antifungal agent. Itraconazole is a highly selective inhibitor of fungal cytochrome P-450 sterol C-14 α-demethylation via the inhibition of the enzyme cytochrome P450 14α-demethylase. This enzyme converts lanosterol to ergosterol, and is required in fungal cell wall synthesis. The subsequent loss of normal sterols correlates with the accumulation of 14 α-methyl sterols in fungi and may be partly responsible for the fungistatic activity of fluconazole. Mammalian cell demethylation is much less sensitive to fluconazole inhibition. Itraconazole exhibits in vitro activity against Cryptococcus neoformans and Candida spp. Fungistatic activity has also been demonstrated in normal and immunocompromised animal models for systemic and intracranial fungal infections due to Cryptococcus neoformans and for systemic infections due to Candida albicans.

Metabolism

Itraconazole is extensively metabolized by the liver into a large number of metabolites, including hydroxyitraconazole, the major metabolite. The main metabolic pathways are oxidative scission of the dioxolane ring, aliphatic oxidation at the 1-methylpropyl substituent, N-dealkylation of this 1-methylpropyl substituent, oxidative degradation of the piperazine ring and triazolone scission.