What is Loprox?

Loprox is a prescription medication used to treat fungal infections of the skin. This includes athlete’s foot, jock itch, and ringworm. Loprox belongs to a class of drugs called antifungals. It works by stopping the growth of fungus.

Loprox

Health Benefits

Loprox may be used for the following:

Treating fungal infections of the skin such as athlete’s foot, jock itch, and ringworm

Side Effects

Common side effects of Loprox include:

Itching

Burning

Irritation

Redness

Rare but serious side effects include: Allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); severe burning, stinging, or irritation of the treated skin. If these effects persist or worsen, notify your doctor.

Seek immediate medical attention if you experience any symptoms of a serious allergic reaction including: rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue. If you notice other effects not listed above, contact your doctor or pharmacist.

Dosages

The recommended adult dose of Loprox for the treatment of superficial fungal infections of the skin is as follows:

Cream: Apply a thin layer to the affected area 2 times daily and rub in gently.

Gel: Apply a thin layer to the affected area 2 times daily and rub in gently.

Solution: Apply a thin layer to the affected area 2 times daily and rub in gently.

You should use Loprox for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antifungal medication. Loprox will not treat a viral skin infection such as the common cold or flu.

Interactions

Inform your doctor of all medications you use, start, or stop using, especially: other antifungal medications such as ketoconazole, miconazole, terbinafine; birth control pills; blood thinners; cancer medicine; cholesterol-lowering medicine; corticosteroids (prednisone); cyclosporine; heart rhythm medicine; HIV/AIDS medicine; seizure medicine; St. John’s wort.

This list is not complete and many other drugs may interact with Loprox. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here. Tell each of your health care providers about all your medical conditions and all your medications. Do not start a new medication without telling your doctor.

Mechanism of Action

Loprox is an antifungal agent with activity against a variety of dermatophytes and yeasts. The precise mechanism(s) of action have not been fully elucidated but appear to be related to the ability of Loprox to inhibit biosynthesis of ergosterol, an essential component of fungal cell membranes. Ergosterol is a precursor in the synthesis of other sterols, such as cholesterol, and its loss probably disrupts membrane function. In vitro studies demonstrate that Loprox is fungicidal against dermatophyte organisms including Trichophyton rubrum and T. mentagrophytes (athlete’s foot), Epidermophyton floccosum (ringworm), Candida albicans, and pityrosporum species (seborrheic dermatitis).

Loprox has in vitro activity against certain bacteria including Staphylococcus aureus and Streptococcus pyogenes. However, the clinical significance of this activity is unknown.

Pharmacokinetics

After topical application of Loprox cream, gel, or solution to human skin, ciclopirox is absorbed through the skin and systemically metabolized. In a study in which 6 healthy subjects received Loprox cream (8%), maximum plasma concentrations of 2.6 ng/mL were attained approximately 1 hour after dosing and declined with a half-life of 10 hours. In another study in which 6 healthy subjects received Loprox gel (8%), maximum plasma concentrations of 5 ng/mL were attained 3 hours after dose administration.

In vitro binding studies using human serum proteins indicate that ciclopirox binds 96% to albumin and 4% to alpha1-acid glycoprotein. Concentrations of ciclopirox in excess of those achievable with topical application have no effect on plasma proteins.

Special Populations

No pharmacokinetic studies have been conducted in special populations.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term animal studies to evaluate the potential for carcinogenicity or mutagenesis have not been performed with Loprox. Ciclopirox was not mutagenic in the Ames test or mouse lymphoma assay, and did not increase unscheduled DNA synthesis in primary rat hepatocytes. Ciclopirox did not induce chromosomal aberrations in human lymphocytes. Fertility studies conducted in rats showed no effects on mating performance, fertility, or early embryonic development at oral doses up to 150 mg/kg/day (approximately 7 times the maximum recommended human dose based on body surface area comparisons).

Clinical Studies

Tinea Pedis and Tinea Cruris

The efficacy of Loprox cream in the treatment of tinea pedis was demonstrated in 2 randomized, vehicle-controlled trials. In these trials, 598 subjects with tinea pedis were randomized to receive either Loprox cream or vehicle once daily for 4 weeks. The mycological cure rates at the end of therapy and at 4 and 8 weeks after therapy were significantly greater for subjects treated with Loprox cream than those treated with vehicle.