Clotrimazole

Clotrimazole

Systematic (IUPAC) name
1-[(2-Chlorophenyl)(diphenyl)methyl]-1H-imidazole
Clinical data
Trade names	Lotrimin, Desenex, Canesten
AHFS/Drugs.com	monograph
MedlinePlus	a682753
Pregnancy category	AU: A C (oral) and B (topical) (US)
Routes of administration	topical, troche
Legal status
Legal status	US: OTC (topical), prescription (oral)
Pharmacokinetic data
Bioavailability	Poor oral absorption (troche), negligible absorption through intact skin (topical)
Protein binding	90%
Metabolism	hepatic
Biological half-life	2 hours
Identifiers
CAS Number	23593-75-1
ATC code	A01AB18 (WHO) D01AC01 G01AF02 QJ02AB90
PubChem	CID 2812
IUPHAR/BPS	2330
DrugBank	DB00257
ChemSpider	2710
UNII	G07GZ97H65
KEGG	D00282
ChEBI	CHEBI:3764
ChEMBL	CHEMBL104
Chemical data
Formula	C22H17ClN2
Molar mass	344.837 g/mol
SMILES Clc1ccccc1C(c2ccccc2)(c3ccccc3)n4ccnc4
InChI InChI=1S/C22H17ClN2/c23-21-14-8-7-13-20(21)22(25-16-15-24-17-25,18-9-3-1-4-10-18)19-11-5-2-6-12-19/h1-17H Key:VNFPBHJOKIVQEB-UHFFFAOYSA-N
(verify)

Clotrimazole (brand name Canesten or Lotrimin) is an antifungal medication commonly used in the treatment of fungal infections (of both humans and other animals) such as vaginal yeast infections, oral thrush, and ringworm. It is also used to treat athlete's foot and jock itch.^[1] It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.^[2]

Medical uses

Canesten (clotrimazole) antifungal cream

It is commonly available without a prescription in various dosage forms, such as a cream, vaginal tablet, or as a prescription troche or throat lozenge (prescription only). Topically, clotrimazole is used for vulvovaginal candidiasis (yeast infection) or yeast infections of the skin. For vulvovaginal candidiasis (yeast infection), clotrimazole tablets and creams are inserted into the vagina. Troche or throat lozenge preparations are used for oropharyngeal candidiasis (oral thrush) or prophylaxis against oral thrush in neutropenic patients.

Clotrimazole is usually used 5 times daily for 14 days for oral thrush, twice daily for 2 to 8 weeks for skin infections, and once daily for 3 or 7 days for vaginal infections.^[3]

Clotrimazole is also commonly used in conjunction with betamethasone as a topical cream for tinea corporis (ringworm), tinea cruris (jock itch), or tinea pedis (athlete's foot).

Topical and oral clotrimazole can be used in both adult and pediatric populations.

Additionally, clotrimazole may be used to treat the sickling of cells (related to sickle cell anemia).^[4][5]

Pregnancy

Small amounts of clotrimazole may be absorbed systemically following topical and vaginal administration. However, this may still be used to treat yeast infections in pregnant women.^[6]

Side effects

Side effects of the oral formulation include itching, nausea, and vomiting. >10% of patients using the oral formulation may have abnormal liver function tests. For this reason, liver function tests should be monitored periodically when taking the oral clotrimazole (troche). When used to treat vulvovaginal candidiasis (yeast infection), <10% of patient have vulvar or vaginal burning sensation. <1% of patients have the following side effects: Burning or itching of penis of sexual partner; polyuria; vulvar itching, soreness, edema, or discharge ^{[7] [8] [9]}

Clotrimazole creams and suppositories contain oil which may weaken latex condoms and diaphragms.^[10]

Drug interactions

There are no known significant drug interactions with topical clotrimazole. However, with oral (troche) clotrimazole, there are multiple interactions as the medication is a CYP450 enzyme inhibitor, primarily CYP3A4. Thus, any medication that is metabolized by the CYP3A4 enzyme will potentially have elevated levels when oral clotrimazole is used. The prescribing physician should be aware of any medication the patient is taking prior to starting oral clotrimazole. Certain medications should not be taken with oral clotrimazole.^[11]

Mechanism of action

Clotrimazole works to kill individual Candida or fungal cells by altering the permeability of the fungal cell wall. It binds to phospholipids in the cell membrane and inhibits the biosynthesis of ergosterol and other sterols required for cell membrane production. This leads to the cell's death via loss of intracellular elements.^{[12] [13]}

References

1. American Society of Health-System Pharmacists, Inc. "Clotrimazole". NIH. Retrieved 19 April 2014.
2. "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
3. "Clotrimazole: MedlinePlus Drug Information". The American Society of Health-System Pharmacists, Inc. Retrieved 17 April 2014.
4. Marieb & Hoehn, (2010). Human Anatomy and Physiology, p. 643. Toronto: Pearson
5. Rodgers, Griffin. "Hydroxyurea and other disease-modifying therapies in sickle cell disease". UpToDate. Retrieved 14 April 2014.
6. "Diseases Characterized by Vaginal Discharge". CDC. Retrieved 17 April 2014.
7. "Clotrimazole: MedlinePlus Drug Information". The American Society of Health-System Pharmacists, Inc. Retrieved 17 April 2014.
8. "Clotrimazole". DrugBank. Retrieved 17 April 2014.
9. "Clotrimazole (Oral)". Lexicomp Online. Retrieved 17 April 2014.
10. "Diseases Characterized by Vaginal Discharge". CDC. Retrieved 17 April 2014.
11. "Clotrimazole". DrugBank. Retrieved 17 April 2014.
12. "Clotrimazole (Oral)". Lexicomp Online. Retrieved 17 April 2014.
13. "Clotrimazole". DrugBank. Retrieved 17 April 2014.