Efinaconazole is triazole used as a 10% topical solution for the treatment of onychomycosis, a fungal infection of the nails. It was approved for use in Canada and the USA in 2014 and is marketed by Valeant Pharmaceuticals North America LLC under the name Jublia. Like other antifungal triazoles, efinaconazole inhibits the fungal cytochrome P450 enzyme lanosterol 14α demethylase (CYP51), thereby disrupting ergosterol synthesis and, consequently, membrane integrity and growth in fungi. CYP51 is evolutionarily conserved and, in mammals, mediates conversion of lanosterol to meiosis-activating sterols (MAS); MAS are intermediates in the biosynthesis of cholesterol and may have a signaling role in initiating meiosis and oocyte maturation. Azoles have higher affinity for fungal CYP51 compared to the mammalian enzyme and such selectivity contributes to the safety of this therapeutic class. Azoles have been reported to produce reproductive and developmental toxicity in both humans and laboratory animals. The mechanism is unknown but inhibition of mammalian CYP51 as well as other CYPs, e.g. CYP17, CYP19 and CYP26, have been postulated to play a role.

Tavaborole is a boron-based pharmaceutical agent indicated for the topical treatment of toenail onychomycosis, a fungal infection of the nail and nail bed due to Trichophyton rubrum or Trichophyton mentagrophytes infection. Tavaborole acts by inhibiting an aminoacyl-transfer ribonucleic acid (tRNA) synthetase (AARS) - Leucyl-tRNA synthetase. Leucyl-tRNA synthetase is an essential fungal enzyme required for protein synthesis and for the catalysis of ATP-dependent ligation of L-leucine to tRNA(Leu). Tavaborole’s low molecular weight (approximately half of most antifungals, such as terbinafine and efinaconazole) permits optimal nail plate penetration, superior to that of existing topical antifungal medications.

Luliconazole (trade names Luzu, Lulicon) is an imidazole antifungal drug. As a 1% topical cream, It is indicated for the treatment of athlete's foot, jock itch, and ringworm caused by dermatophytes such as Trichophyton rubrum, Microsporum gypseum and Epidermophyton floccosum. Luliconazole is an antifungal that belongs to the azole class. Although the exact mechanism of action against dermatophytes is unknown, luliconazole appears to inhibit ergosterol synthesis by inhibiting the enzyme lanosterol demethylase. Inhibition of this enzyme’s activity by azoles results in decreased amounts of ergosterol, a constituent of fungal cell membranes, and a corresponding accumulation of lanosterol. Pharmacokinetic and safety results from phase 1 studies in patients with onychomycosis have demonstrated high concentrations of luliconazole within the nail plates of the great toe and have shown that this agent is well tolerated when administered as a 10% solution.

SPORANOX is the brand name for itraconazole, an azole antifungal agent. Itraconazole is a 1:1:1:1 racemic mixture of four diastereomers (two enantiomeric pairs), each possessing three chiral centers. In vitro studies have demonstrated that itraconazole inhibits the cytochrome P450-dependent synthesis of ergosterol, which is a vital component of fungal cell membranes. As ergosterol is an essential component of the fungal cell membrane, inhibition of its synthesis results in increased cellular permeability causing leakage of cellular contents. Itraconazole may also inhibit endogenous respiration, interact with membrane phospholipids, inhibit the transformation of yeasts to mycelial forms, inhibit purine uptake, and impair triglyceride and/or phospholipid biosynthesis. SPORANOX capsules are indicated for the treatment of the following fungal infections in immunocompromised and non-immunocompromised patients: Blastomycosis, pulmonary and extrapulmonary; Histoplasmosis, including chronic cavitary pulmonary disease and disseminated, nonmeningeal histoplasmosis, and Aspergillosis, pulmonary and extrapulmonary, in patients who are intolerant of or who are refractory to amphotericin B therapy. SPORANOX is also indicated for the treatment of the following fungal infections in non-immunocompromised patients: Onychomycosis of the toenail, with or without fingernail involvement, due to dermatophytes (tinea unguium), and Onychomycosis of the fingernail due to dermatophytes (tinea unguium). Itraconazole is mainly metabolized through CYP3A4. Other drugs that either share this metabolic pathway or modify CYP3A4 activity may influence the pharmacokinetics of itraconazole. Similarly, itraconazole may modify the pharmacokinetics of other drugs that share this metabolic pathway. Itraconazole is a potent CYP3A4 inhibitor and a P-glycoprotein inhibitor. When using concomitant medication, it is recommended that the corresponding label be consulted for information on the route of metabolism and the possible need to adjust dosages.

Terbinafine (brand name Lamisil, Terbisil, Terboderm and others) is an antifungal medication used to treat ringworm and fungal nail infections. Terbinafine inhibits ergosterol synthesis by inhibiting squalene epoxidase, an enzyme that is part of the fungal cell membrane synthesis pathway. Because terbinafine prevents the conversion of squalene to lanosterol, ergosterol cannot be synthesized. This is thought to change cell membrane permeability, causing fungal cell lysis. Many side effects and adverse drug reactions have been reported with oral terbinafine hydrochloride possibly due to its extensive biodistribution and the often extended durations involved in antifungal treatment (longer than two months).

Ravuconazole is a triazole with antifungal properties that inhibits cytochrome P450 sterol 14a-demethylase, an enzyme involved in sterol synthesis, resulting in lysis of the fungal cell wall and fungal cell death. It was investigated for the treatment of aspergillosis, candidiasis, and onychomycosis, but these studies were discontinued. Ravuconazole is now in phase II clinical trials to investigate efficacy in preventing fungal infections in patients undergoing chemotherapy and stem cell transplantation.

Albaconazole is a triazole antifungal. Azoles are important antifungal compounds, and all drugs in this class inhibit ergosterol synthesis by blocking the 14-α-demethylase enzyme, resulting in the accumulation of toxic methylsterols that may culminate in fungal death. Albaconazole, an oral agent that has demonstrated high levels of bioavailability and potent antifungal activity. It was under development for the treatment of onychomycosis, vulvovaginal candidiasis. Also, albaconazole was evaluated in phase I, a randomized, placebo-controlled clinical trial in patients with tinea pedis. No serious adverse effects occurred in the studies involving albaconazole. However, this researches on this drug were discontinued.

Chloranil is an oxidant, practically useful for dehydrogenation to aromatic and alpha,beta-desaturated carbonyl compounds. Chloranil was found to inhibit human carboxylesterases: carboxylesterase 1 and 2, acetylcholinesterase and butyrylcholinesterase. In 1950s chloranil ointment was used for the treatment of psoriasis and onychomycosis.

Amorolfine (or amorolfin), is a morpholine antifungal drug with broad spectrum of activity. Its fungicidal action is based on an alteration of the fungal cell membrane targeted primarily on sterol biosynthesis. Amorolfine is administered as a nail lacquer in patients suffering from onychomycosis, as a cream in patients suffering from dermatomycosis. Amorolfine is well tolerated. The local adverse effects observed were mainly burning and itching.

Abafungin is a broad-spectrum antifungal agent with a novel mechanism of action for the treatment of dermatomycoses and onychomycosis. Abafungin acts through inhibition of transmethylation at the C-24 position of the sterol side chain, catalyzed by the enzyme sterol-C-24-methyltransferase. Abasol is a topical cream formulation of abafungin seeking approval in 2008 in European markets.