Possible dosage regimens for topical steroids, assessed by vasoconstrictor assays using multiple applications

Area of Science:

• Dermatology
• Pharmacology

Background:

• Topical corticosteroids are widely used for inflammatory skin conditions.
• Optimizing the dosage regimen of topical corticosteroids is crucial for maximizing efficacy and minimizing side effects.

Purpose of the Study:

• To evaluate and compare the bioavailabilities and vasoconstrictor activities of three amcinonide preparations and Betnovate cream.
• To determine the most advantageous dosage regimen for topical corticosteroid application.

Main Methods:

• A vasoconstrictor assay was employed with 10 healthy volunteers.
• Multiple dosage regimens were tested: once daily, twice daily, and every alternate day, with an initial three times daily loading dose on day one.
• Skin blanching responses were measured to assess drug activity.

Main Results:

• All tested amcinonide preparations and Betnovate cream demonstrated vasoconstrictor activity.
• Tachyphylaxis, a decrease in response over time, was observed with repeated applications.
• The blanching response initially increased and subsequently decreased, indicating tachyphylaxis.

Conclusions:

• The observed tachyphylaxis suggests that frequent application of topical corticosteroids may lead to diminished efficacy.
• A once-daily application regimen, without a loading dose, is proposed as the most clinically beneficial approach.
• This regimen may offer a better balance between efficacy and potential side effects like tachyphylaxis.