Reduction in ultraviolet B light-induced erythema by oxymetazoline and brimonidine is mediated by different α-adrenoceptors

Efficacy and safety of oxymetazoline for the treatment of rosacea: A meta-analysis

BACKGROUND

Since there is currently no conclusion on the efficacy and adverse effects of oxymetazoline, this meta-analysis attempts to explore its efficacy and adverse events, so as to provide guidance for clinical medication.

METHODS

We searched PubMed, Embase, and Cochrane Library from the establishment of the database to May 2021. We included studies that patients were randomly assigned to receive oxymetazoline or vehicle, and we excluded duplicate publications, research without full text, incomplete information or inability to conduct data extraction, animal experiments, reviews, and systematic reviews. STATA 15.1 was used to analyze the data.

RESULTS

The pooled results show that the 3 (RR = 1.76, 95% CI: 1.53-2.03), 6 (RR = 1.71, 95% CI: 1.47-2.00), 9 (RR = 1.63, 95% CI: 1.40-1.90), 12 (RR = 1.41, 95% CI: 1.18-1.67) -hours CEA success rate and the 3 (RR = 1.65, 95% CI: 1.34-2.03), 6 (RR = 1.75, 95% CI: 1.43-2.14), 9 (RR = 1.63, 95% CI: 1.33-2.00), 12 (RR = 1.78, 95% CI: 1.45-2.18) -hours SSA success rate after oxymetazoline treatment for rosacea is significantly higher than that of vehicle. Additionally, the pooled results show that the incidence of TEAEs after treatment with oxymetazoline is significantly higher than that of vehicle (RR = 1.34, 95% CI: 1.10-1.2). However, our analysis of specific adverse events found that the oxymetazoline group was only significantly higher than the vehicle group in the incidence of application-site dermatitis (RR = 8.91, 95% CI: 1.76-45.23), and there was no statistical significance in the difference in the incidence of other adverse events.

CONCLUSION

Oxymetazoline is effective and can be selected for the treatment of persistent facial erythema of rosacea. Additionally, application-site dermatitis was the most important one.

The role of the topical nasal decongestant oxymetazoline as a novel therapeutic option for post-acne erythema: A split-face, double-blind, randomized, placebo-controlled trial

Post-acne erythema (PAE) is one of the most common sequelae of acne inflammation. Unfortunately, the treatment of PAE remains challenging due to limited effective topical treatments. The objectives of this study were to evaluate the efficacy and safety of topical oxymetazoline hydrochloride (OxH) 0.05% solution for PAE. This study was a split-face, participants-and investigators-blinded, randomized, placebo-controlled trial conducted between December 2021 and March 2022 in Bangkok, Thailand. Healthy adults aged from 18 to 45 years with mild to severe PAE, according to the Clinician's Erythema Assessment (CEA), on both sides of the face were eligible. After randomization, each participant applied the OxH to one side of their face and a placebo to the contralateral face twice daily for 12 weeks. The primary outcome was PAE lesion counts. The secondary outcomes were erythema index, clinical response rate at week 12 ("clear," "almost clear," or "at least two-grade improvement" by CEA), and patient satisfaction scores. A total of 30 participants were enrolled. The OxH-treated skin showed a significantly greater mean difference (MD) reduction in PAE lesion counts than the placebo after 8 weeks of treatment (4.30, 95% confidence interval [CI] 1.42-7.18). Similarly, the MD reduction of the erythema index was higher in the OxH-treated skin from the second week (11.82, 95% CI 8.48-15.15). Additionally, the OxH-treated side also achieved a higher clinical response rate after 8 weeks of treatment (40.00% vs. 6.67%; p = 0.002) and rated higher satisfaction than those using the placebo at the end of the study (mean [standard deviation] satisfaction score 8.30 [0.18] vs 7.40 [0.18], P < 0.001). There were no serious adverse events or flares of erythema during the study. In conclusion, our study demonstrated that the topical OxH 0.05% solution was effective, well-tolerated, and safe for reducing PAE without a rebound effect. It could be a choice of PAE management. Trial Registration: Thai Clinical Trials Registry No. TCTR20211207004.

Topical Brimonidine Delays Ultraviolet Radiation-Induced Squamous Cell Carcinoma in Hairless Mice

We investigated whether topical brimonidine delayed or enhanced the development of squamous cell carcinoma (SCC) when ultraviolet radiation (UVR) was applied to a well-established murine model. Hairless female mice (n = 125) were randomized into five groups and treated as follows: 1% brimonidine cream before UVR (Group 1), 0.33% brimonidine gel before UVR (Group 2), 1% brimonidine cream after UVR (Group 3), UVR only (control; Group 4) and 1% brimonidine cream only (control; Group 5). For each animal, the first four tumors were recorded and followed until three tumors reached 4 mm or one tumor reached 12 mm in diameter. All animal experiments continued for up to 365 days or until death. Application of 1% brimonidine cream before UVR delayed tumor development relative to control mice treated with UVR alone (P = 0.000006). However, when 0.33% brimonidine gel was applied before UVR (P = 0.313) or 1% brimonidine cream was applied after UVR (P = 0.252), there was no significant delay in tumor development relative to control mice treated with UVR alone. The development of the second and third tumors followed a similar pattern. Topical 1% brimonidine cream applied before UVR exposure delayed SCC development in hairless mice. In contrast, when brimonidine was applied after UVR there was no significant delay in tumor development. These results suggest that the 1% brimonidine cream probably absorbed the UVR, and therefore, a delay in tumor formation was only seen when brimonidine was applied before irradiation. However, there can be multiple reasons for this delay in photocarcinogenesis.

Murine models of rosacea: a review

Rosacea is a chronic inflammatory disease characterized by facial flushing, erythema, telangiectasia, papules, and pustules. Its pathogenesis has not been fully understood. In 2017, the global ROSacea COnsensus (ROSCO) panel updated the diagnosis, classification, and assessment of rosacea. Phenotype-based treatments and long-term managements have also been recommended. Murine models are a powerful tool in unveiling and dissecting the mechanisms of human diseases. Here, we summarized murine models of rosacea developed or used in previous research, including LL-37 intradermal injection model, KLK-5-induced inflammation model, croton oil inflammation model, 12-O-Tetradecanoylphorbol-13-acetate inflammation model, arachidonic acid inflammation model, RTX-induced vasodilation model, and UVB-induced model. LL-37 injection model has become the most intensively used model in rosacea research. Each model could show the pathophysiological and clinical features of rosacea to some extent. However, no model can show the full picture of the characteristics of rosacea. Improving existed murine models, developing new murine models, and applying them to pathogenesis and treatment research on rosacea are highly warranted in the future.

Difference in vasoconstrictors: oxymetazoline vs. brimonidine

OBJECTIVE

Topical oxymetazoline and brimonidine are the only medications approved for treating persistent facial erythema of rosacea. This review aims to investigate the efficacy, safety, pharmacodynamics, and pharmacokinetic properties of oxymetazoline and brimonidine.

METHODS AND MATERIALS

Phase II and phase III clinical studies evaluating oxymetazoline and brimonidine were assessed to compare their efficacy and safety.

RESULTS

In their respective phase III trials, both oxymetazoline and brimonidine met the primary efficacy outcome of having at least a 2-grade decrease from baseline on both the Clinician Erythema Assessment (CEA) and the Subject Self-Assessment (SSA) Scales compared to the vehicle control. Treatment related adverse events of oxymetazoline and brimonidine are most often mild and localized.

CONCLUSIONS

Topical oxymetazoline and brimonidine are effective for the management of persistent facial erythema associated with rosacea with a few mild and localized adverse effects. Further long-term research is imperative to further understand their long-term effects.