Tolerability of Topical Treatments for Atopic Dermatitis.

Atopic dermatitis (AD) is a common inflammatory skin disease that is accompanied by increased sensitivity to itch-provoking and pain-provoking stimuli. Patients with AD experience skin pain before initiation of therapy and have also reported painful application site reactions in clinical trials of emollients and prescription topical therapies, including topical corticosteroids (TCSs), topical calcineurin inhibitors (TCIs), and a topical phosphodiesterase 4 (PDE4) inhibitor. To compare the sensory tolerability of prescription topical therapies for AD, a comprehensive literature search and analysis of published clinical trials was conducted. Sensory tolerability issues such as application site pain, burning, stinging, and pruritus were often among the most common adverse events or treatment-related adverse events in clinical trials for prescription topical therapies. Tolerability issues occurred at highest rates in trials of TCIs, followed by trials of the PDE4 inhibitor crisaborole and TCSs, although direct comparisons are not possible because of differences in study design. Tolerability issues in these clinical trials were generally mild to moderate and transient. This article also reviews published strategies for managing sensory tolerability issues in AD patients during treatment with topical therapies.Funding: Pfizer Inc., New York, NY.

Efficacy and safety of tavaborole topical solution, 5%, a novel boron-based antifungal agent, for the treatment of toenail onychomycosis: Results from 2 randomized phase-III studies.

BACKGROUND: Onychomycosis, a fungal nail infection, can impact quality of life. OBJECTIVE: We sought to evaluate the efficacy and safety of tavaborole topical solution, 5% for treatment of toenail onychomycosis. METHODS: In 2 phase-III trials, adults with distal subungual onychomycosis affecting 20% to 60% of a target great toenail were randomized 2:1 to tavaborole or vehicle once daily for 48 weeks. The primary end point was complete cure of the target great toenail (completely clear nail with negative mycology) at week 52. Secondary end points included completely or almost clear nail, negative mycology, completely or almost clear nail plus negative mycology, and safety. RESULTS: Rates of negative mycology (31.1%-35.9% vs 7.2%-12.2%) and complete cure (6.5% and 9.1% vs 0.5% and 1.5%) significantly favored tavaborole versus vehicle (P ≤ .001). Completely or almost clear nail rates also significantly favored tavaborole versus vehicle (26.1%-27.5% vs 9.3%-14.6%; P < .001). Rates of completely or almost clear nail plus negative mycology (15.3%-17.9% vs 1.5%-3.9%) were significantly greater for tavaborole versus vehicle (P < .001). Application-site reactions with tavaborole included exfoliation (2.7%), erythema (1.6%), and dermatitis (1.3%). LIMITATIONS: Duration of follow-up is a limitation. CONCLUSION: Tavaborole demonstrates a favorable benefit-risk profile in treatment of toenail onychomycosis.

Receptor-ligand interaction at 5-HT3 serotonin receptors: a cluster approach.

A fundamental understanding of the interaction of ligands with biological receptors is important because many drugs exert their influence via receptors. Using a cluster approach, we have studied the role of structural and electronic parameters on receptor-ligand binding by carrying out density functional theory based calculations. As model systems, we have studied substituted arylguanidines, which activate 5-HT3 receptors in a manner similar to that of serotonin. The geometries of the arylguanidine derivatives were fully optimized to obtain the lowest energy structures. Electronic properties such as binding energies, dipole moments, polarizabilities, and electron affinities, as well as geometric properties, such as molecular volume and dihedral angles were calculated, and their relationship with binding affinity was evaluated. Results obtained were compared to experimental ligand-receptor binding affinity data available. These fundamental studies show that though both electronic and geometric properties of the ligands are important for binding, the electron affinities of the substituent species play a dominant role. Potential new fundamental indices for ligand-receptor affinity are also discussed.