home > drugs a-z list > xolegel (ketoconazole) drug center > xolegel (ketoconazole) drug - clinical pharmacology

Mechanism of Action

The mechanism of action of ketoconazole in the treatment of seborrheic dermatitis is unknown.

Pharmacodynamics

Pharmacodynamic markers for seborrheic dermatitis have not been identified.

Pharmacokinetics

In a pharmacokinetic absorption trial, eighteen subjects, both males and females, with severe seborrheic dermatitis (range 1-14% of body surface area) applied XOLEGEL (ketoconazole) once daily for 2 weeks. The median total amount of gel applied was 4.6 g (range 1.65-46.3 g). Daily doses ranged from 0.05 to 3.47 g. Mean (± standard deviation [SD]) peak plasma levels were 1.35 (±3.18) ng/mL on Day 7 (range from < 0.1 ng/mL, to 13.9 ng/mL), and 0.80 (± 1.22) ng/mL on Day 14 (range from < 0.1 ng/mL to 5.4 ng/mL). Median Tmax was 8 hours on Day 7 and 7 hours on Day 14. Mean (± SD) AUC_0-24 values were 20.8 (± 44.7) ng·h/mL and 15.6 (± 26.4) ng·h/mL on Day 7 and 14, respectively.

The plasma levels from an oral dose of 200 mg ketoconazole taken with a meal are approximately 250 times higher than the resulting plasma levels of ketoconazole following topical application of XOLEGEL (ketoconazole) .

Clinical Studies

Study 1 was a multicenter, double-blind, randomized, vehicle-controlled trial which enrolled 459 subjects 12 years of age and older with moderate to severe seborrheic dermatitis. A total of 229 subjects were treated with XOLEGEL (ketoconazole) , and 230 subjects were treated with vehicle. All subjects were treated once daily for 14 days, and efficacy was assessed at Day 28 (i.e., 2 weeks after end of treatment). Effective Treatment was defined as:

• an Investigator's Global Assessment score of ≤ 1 (completely clear or almost clear) and
• erythema and scaling scores of 0 (none) if the baseline score was 2, or 1 (mild) if the baseline score was 3. The proportion of subj ects effectively treated is shown in Table 1.

Table 1: Trial Results

Two additional double-blind, randomized, vehicle-controlled, parallel, and multi-center trials that included a total of 316 subjects treated with XOLEGEL (ketoconazole) provided supportive evidence of the efficacy of XOLEGEL (ketoconazole) for treatment of seborrheic dermatitis. Subjects applied either XOLEGEL (ketoconazole) or vehicle study treatment to the affected area(s) once daily for 14 days and were followed through Day 28. Efficacy was assessed by the proportion of subjects who were completely clear at Day 28.

The contribution to efficacy of individual components of the vehicle has not been established.

Last reviewed on RxList: 1/31/2011
This monograph has been modified to include the generic and brand name in many instances.