Contents

Ciclopirox

Ciclopirox

Clinical data
Trade names	Many[1]
Other names	Loprox, CPX
AHFS/Drugs.com	Micromedex Detailed Consumer Information
MedlinePlus	a604021
Pregnancy category	B
Routes of administration	Topical
ATC code	D01AE14 (WHO) G01AX12 (WHO)
Legal status
Legal status	AU: S2 (Pharmacy medicine) CA: ℞-only US: ℞-only
Pharmacokinetic data
Bioavailability	<5% with prolonged use
Protein binding	94 to 97%
Elimination half-life	1.7 hours
Identifiers
IUPAC name 6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one
CAS Number	29342-05-0 Y
PubChem CID	2749
DrugBank	DB01188 Y
ChemSpider	2647 Y
UNII	19W019ZDRJ
KEGG	D03488 Y
ChEBI	CHEBI:453011 Y
ChEMBL	ChEMBL1413 Y
CompTox Dashboard (EPA)	DTXSID9048564
ECHA InfoCard	100.045.056
Chemical and physical data
Formula	C12H17NO2
Molar mass	207.273 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C1/C=C(\C=C(/N1O)C2CCCCC2)C
InChI InChI=1S/C12H17NO2/c1-9-7-11(13(15)12(14)8-9)10-5-3-2-4-6-10/h7-8,10,15H,2-6H2,1H3 Y Key:SCKYRAXSEDYPSA-UHFFFAOYSA-N Y
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Ciclopirox is a synthetic antifungal agent for topical dermatologic treatment of superficial mycoses. It is most useful against tinea versicolor. It is often used clinically as ciclopirox olamine, the olamine salt of ciclopirox.

In 2021, it was the 271st most commonly prescribed medication in the United States, with more than 900,000 prescriptions.^[2][3]

Ciclopirox is indicated for the treatment of tinea pedis and tinea corporis due to Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum, as well as seborrheic dermatitis. It is not to be used in the eyes or vagina, and nursing women should consult their doctors before use, since it is not known whether ciclopirox passes into human milk. A burning sensation may be felt when first applying ciclopirox on the skin.^{[citation needed]}

In addition to other formulations, ciclopirox is used in lacquers for topical treatment of onychomycosis (fungal infections of the nails). A meta-analysis of the six trials of nail infections available in 2009 concluded that they provided evidence that topical ciclopirox had poor cure rates, and that amorolfine might be substantially more effective, but more research was required. "Combining data from 2 trials of ciclopiroxolamine versus placebo found treatments failure rates of 61% and 64% for ciclopiroxolamine. These outcomes followed long treatment times (48 weeks) and this makes ciclopiroxolamine a poor choice for nail infections. Better results were observed with the use of amorolfine lacquer; 6% treatment failure rates were found after 1 month of treatment but these data were collected on a very small sample of people and these high rates of success might be unreliable."^[4]

Efinaconazole, an azole antifungal, led to cure rates two or three times better than the next-best topical treatment, ciclopirox.^[5]

In contrast to the azoles and other antimycotic drugs, the mechanism of action of ciclopirox is poorly understood.^[6] However, loss of function of certain catalase and peroxidase enzymes has been implicated as the mechanism of action, as well as various other components of cellular metabolism. In a study conducted to further elucidate ciclopirox's mechanism, several Saccharomyces cerevisiae mutants were screened and tested. Results from interpretation of the effects of both the drug treatment and mutation suggested that ciclopirox may exert its effect by disrupting DNA repair, cell division signals and structures (mitotic spindles) as well as some elements of intracellular transport.^[7]

Ciclopirox is a N-hydroxypyridone. Structurally, ciclopirox is the N-oxide of a 2-hydroxypyridine derivative and therefore can be termed a hydroxypyridine antifungal agent. Additionally, the structure as drawn above is the lactam tautomer and indicates the molecule being an N-hydroxy-2-pyridone. Hence the classification of ciclopirox as a 2-pyridone antifungal agent.^{[citation needed]}

It is sold under many brand names worldwide.^[1]

In 2007 it was investigated as an alternative treatment to ketoconazole for seborrhoeic dermatitis as it suppresses growth of the yeast Malassezia furfur. Initial results showed similar efficacy to ketoconazole with a relative increase in subjective symptom relief due to its inherent anti-inflammatory properties.^[8]