Antifungal drugs

While fluconazole can alter the pharmacokinetics of certain drugs that undergo hepatic metabolism, the magnitude of such alterations appears to be less than those associated with ketoconazole; however, comparative studies have not been performed to date. In addition, the possibility that the risk of developing such interactions may be increased at relatively high fluconazole dosages (e.g., 200 mg daily or more) should be considered. Results of studies evaluating combined use of fluconazole and amphotericin B in animal models of aspergillosis, candidiasis, or cryptococcosis have been conflicting.

Fluconazole is administered orally or by IV infusion. Since absorption of fluconazole from the GI tract is rapid and almost complete, IV therapy with the drug generally is reserved for patients who do not tolerate or are unable to take the drug orally.

Terbinafine hydrochloride is a synthetic allylamine antifungal agent. Terbinafine is structurally and pharmacologically related to naftifine.

Itraconazole (Sporonox) is available as a capsule and two solution formulations, one for oral and one for intravenous administration. The capsule form of the drug is best absorbed in the fed state, but the oral solution is better absorbed in the fasting state, providing peak plasma concentrations that are more than 150% of those obtained with the capsule. Both the oral solution and intravenous formulation are solubilized in a 40:1 weight ratio of itraconazole hydroxypropyl-β-cyclodextrin, so that administration of 200 mg of itraconazole provides 8 g of this excipient.

Ketoconazole is an antifungal agent that impairs synthesis of ergosterol, allowing increased permeability in fungal cell membrane and leakage of cellular components. It is indicated in the treatment of susceptible systemic and cutaneous fungal infections. Topical: used for seborrheic dermatitis, tinea corporis, tinea cruris, tinea pedis, and tinea versicolor. Ketoconazole (200 mg daily) is indicated in the treatment of the following systemic fungal infections: candidiasis, chronic mucocutaneous candidiasis, oral thrush, candiduria, blastomycosis, coccidiomycosis, histoplasmosis, chromomycosis, and paracoccidioidomycosis.

Terbinafine is an infective / antifungal agent that inhibits squalene epoxidase, resulting in ergosterol deficiency and a corresponding accumulation of squalene within the fungal cell leading to fungal cell death. It is indicated in the treatment of onychomycosis of the toenail or fingernail caused by dermatophytes.

Econazole nitrate is a topical / antifungal agent. It increases cell membrane permeability in susceptible fungi. It is indicated in the treatment of tinea pedis (athlete’s foot), tinea cruris (jock itch), tinea corporis (ringworm), cutaneous candidiasis, and tinea versicolor.

An antifungal substance obtained by fermentation using certain strains of Streptomyces noursei. It contains mainly tetraenes, the principal component being nystatin A:. The potency is not less than 4400 units/mg and not less than 5000 units/mg if intended for oral use, calculated with reference to the dried substance. It is a yellow or slightly brownish hygroscopic powder.

Trimetrexate is reported to be incompatible with foscarnet. Trimetrexate should not be mixed with folinic acid or chloride ions, since precipitation occurs instantly.

Natamycin is a polyene antifungal active against Candida and Fusarium spp. In addition it is active against the protozoan Trichomonas vaginalis.