Each ml of Clotrimazole, topical solution 1%, contains:

active ingredient: clotrimazole – 10 mg;

excipients: propylene glycol (48%), methylparaben, ethanol (50%).

Antifungal; A01AB18; D01AC01; G01AF02.

1-(α-2-Chlorotrityl)imidazole; 23593-75-1.

Clotrimazole, an imidazole derivative, is a synthetic azole antifungal agent.

Mechanism of Action

Clotrimazole exerts its antifungal activity by altering cell membrane permeability, apparently by binding with phospholipids in the fungal cell membrane. In contrast to polyene antibiotics (e.g., amphotericin B), the action of Clotrimazole is less dependent on the sterol content of the cell membrane. As a result of alteration of permeability, the cell membrane is unable to function as a selective barrier, and potassium and other cellular constituents are lost.

Antimicrobial Action

Clotrimazole s an imidazole antifungal that interferes with ergosterol synthesis and therefore alters the permeability of the cell membrane of sensitive fungi. It is reported to be fungistatic at concentrations achieved clinically. Clotrimazole has a wide spectrum of antimicrobial activity including activity against Blastomyces dermatitidis, Candida spp., Coccidioides immitis, Epidermophyton floccosum, Histoplasma capsulatum, Malassezia spp., Microsporum canis, Paracoccidioides brasiliensis, Trichophyton mentagrophytes, and T. rubrum. Some strains of Aspergillus spp., Cryptococcus neoformans, and Sporothrix schenckii are sensitive.

Clotrimazole has activity against some Gram-positive bacteria and some antiprotozoal activity against Leishmania spp.

There are rare reports of Candida albicans acquiring resistance to Clotrimazole.

The emergence of strains of Candida spp. resistant to Clotrimazole has become increasingly important, particularly in immunocompromised patients receiving long-term prophylaxis with clotrimazole. In addition to resistance in C. albicans, infections with C. dubliniensis, C. glabrata, and C. krusei, all of which may be less sensitive to Clotrimazole than C. albicans, have been noted in these patients,and secondary resistance of C. glabrata has been reported during clotrimazole therapy. Cross-resistance with other azoles and with amphotericin B has been reported.

When applied topically clotrimazole penetrates the epidermis but there is little if any systemic absorption. Clotrimazole is metabolised in the liver to inactive compounds and excreted in the faeces and urine.

Dermatophytoses and Cutaneous Candidiasis

Clotrimazole is used topically as solution for the treatment of tinea corporis, tinea cruris, and tinea pedis caused by T. rubrum, T. mentagrophytes, E. floccosum, or M. canis and for the treatment of cutaneous candidiasis. Clotrimazole solution also may be used topically for self-medication of tinea pedis, tinea cruris, and tinea corporis caused by T. rubrum, T. mentagrophytes, E. floccosum, or M. canis.

Pityriasis (Tinea) Versicolor

Clotrimazole is used topically as solution for the treatment of pityriasis (tinea) versicolor caused by Malassezia furfur (Pityrosporum orbiculare or P. ovale).

Dermatophytoses and Cutaneous Candidiasis

Clotrimazole is applied topically two or three times daily for 2 to 4 weeks as solution in the treatment of fungal skin infections. The 1% solution is also used topically for fungal otitis externa. Clinical improvement and relief of pruritus usually occur within 1 week; however, up to 8 weeks of therapy may be required for mycological cures, especially in the treatment of tinea pedis. If clinical improvement does not occur after 4 weeks of treatment, the diagnosis should be reevaluated. When Clotrimazole solution is used for self-medication, tinea cruris should usually be treated for 2 weeks and tinea pedis or corporis for 4 weeks; if adequate response has not been achieved after these treatment periods, the drug should be discontinued and a physician or pharmacist consulted.

Pityriasis (Tinea) Versicolor

For the treatment of pityriasis (tinea) versicolor, Clotrimazole 1% solution should be applied sparingly and rubbed gently into the cleansed, affected area and surrounding skin twice daily (in the morning and evening). If clinical improvement does not occur after 4 weeks of treatment, the diagnosis should be reevaluated.

Contact dermatitis has been reported following topical application of imidazole-derivative azole antifungals. Cross-sensitization appears to occur among the imidazole derivatives; however, cross-sensitivity appears to be unpredictable. The fact that patients with contact sensitivity to one imidazole-derivative azole antifungal may be sensitive to other similar drugs should be considered. If irritation or sensitization occurs following topical application of Clotrimazole, the drug should be discontinued.

Clotrimazole solution are not intended for ophthalmic use.

If irritation occurs or if the patient’s dermatologic condition does not improve within 2 weeks for tinea cruris or within 4 weeks for tinea pedis or tinea corporis during self-medication with Clotrimazole solution, treatment should be discontinued and the patient should consult a physician or pharmacist.

Clotrimazole is contraindicated in patients who are hypersensitive to the drug or any ingredient in the formulation.

Pediatric Precautions

For self-medication, Clotrimazole solution should not be used in children younger than 2 years of age unless otherwise instructed by a physician.

Pregnancy

Clotrimazole is reported to be embryotoxic but not teratogenic in rodents given high doses. This drug is used topically and the systemic absorption from these routes of administration varies. While this drug may not necessarily be contra-indicated in pregnancy, consideration should be given to these potential risks when choosing antifungal therapy for such patients.

Lactation

Since it is not known whether Clotrimazole is distributed into milk, the drug should be used with caution in nursing women.

Clotrimazole Topical solution, 1% is supplied in a amber glass botlle (30 ml).

3 years. Do not use after the expiration date.

Store at a room temperature (15-25⁰C), in a dry place, out of the reach of children. Protect from light.