Oral versus topical propranolol for management of superficial infantile hemangiomas: a comparative study

β-blocker therapy for infantile hemangioma

INTRODUCTION

Fifteen percent of proliferating infantile hemangioma (IH) require intervention because of the threat to function or life, ulceration, or tissue distortion. Propranolol is the mainstay treatment for problematic proliferating IH. Other β-blockers and angiotensin-converting enzyme (ACE) inhibitors have been explored as alternative treatments.

AREAS COVERED

The demonstration of a hemogenic endothelium origin of IH, with a neural crest phenotype and multi-lineage differentiation capacity, regulated by the renin-angiotensin system, underscores its programmed biologic behavior and accelerated involution induced by propranolol, other β-blockers and ACE inhibitors. We review the indications, dosing regimens, duration of treatment, efficacy and adverse effects of propranolol, and therapeutic alternatives including oral atenolol, acebutolol, nadolol, intralesional propranolol injections, topical propranolol and timolol, and oral captopril.

EXPERT OPINION

Improved understanding of the biology of IH provides insights into the mechanism of action underscoring its accelerated involution induced by propranolol, other β-blockers and ACE inhibitors. More research is required to understand the optimal dosing and duration, efficacy and safety of these alternative therapies. Recent demonstration of propranolol's actions mediated by non-β-adrenergic isomer R-propranolol on stem cells, offers an immense opportunity to harness the efficacy of β-blockers to induce accelerated involution of IH, while mitigating their β-adrenergic receptor-mediated adverse effects.

The efficacy and safety of treatments for infantile hemangiomas: a Bayesian network meta-analysis

Whether infantile hemangiomas (IHs) need to be treated and which treatment should be preferred are still controversial. We aimed to compare and rank the treatments and identify the optimal treatment for IHs. We searched PubMed, EMBASE, the Cochrane Library, Web of Science, and other sources for randomized controlled trials up to August 2019. We included trials comparingdifferent treatments and reported response or adverse events rate in IH patients. Two reviewers independently evaluated studies by specific criteria and extracted data. We assessed the risk of bias with the Cochrane risk of bias tool. Random-effects were performed for pair-to-pair and Bayesian framework network meta-analyses. The primary outcomes were efficacy and safety. We deemed 20 studies eligible, including 1149 participants and eight interventions. For efficacy, oral propranolol and topical propranolol/timolol were better than observation/placebo (OR, 95% CrI: 17.05, 4.02-94.94; 9.72, 1.91-59.08). For safety, topical propranolol/timolol was significantly better tolerated than oral propranolol (0.05, 0.001-0.66). Cluster analysis demonstrated oral propranolol was the most effective treatment for IHs, while topical propranolol/timolol showed high efficacy and the highest safety. Laser, intralesional propranolol or glucocorticoid, oral glucocorticoid, or captopril had significantly lower priority than oral propranolol or topical propranolol/timolol considering both efficacy and safety. The quality of evidence was rated as moderate or low in most comparisons. This network meta-analysis found topical beta-blockers had the potential to be the most preferable and beneficial option for IHs in consideration of both efficacy and safety.

Efficacy and adverse effects of oral propranolol in infantile hemangioma: a meta-analysis of comparative studies

BACKGROUND

A number of clinical trials evaluated the efficacy and adverse effects of oral propranolol in the treatment of infantile hemangioma (IH), but the treatment has not yet been standardized. This meta-analysis aims to reevaluate the efficacy and adverse effects of oral propranolol in comparative studies and to provide a reliable basis for clinical administration in the therapy for IH.

METHODS

Data were obtained from PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure and Wanfang database, from inception to December 1st, 2018. The pooled risk ratios (RR) with 95% confidence intervals (95% CI) were calculated and used to evaluate the effect size. The meta-analysis was performed using the random-effects model due to heterogeneity between the studies. The Cochrane Collaboration 6 aspects of bias, methodological index for non-randomized studies and the Newcastle-Ottawa Scale were used to assess the risk for bias. Sensitivity analysis, publication bias and subgroup analysis were performed.

RESULTS

Eighteen unique studies involving 2701 unique children were included in the analysis. The response rate was reported in 18 trials, which compared oral propranolol with other treatments. The heterogeneity was statistically significant (P < 0.00001, I² = 95%). The difference in the response rate was statistically significant (RR = 1.40, 95% CI 1.13-1.75) while compared with the controls. However, no significant difference in the adverse events rate (RR = 0.78, 95% CI 0.45-1.34) and relapse rate (RR = 1.45, 95% CI 0.66-3.16) were found. Otherwise, the subgroup analysis indicated that the RR was 1.64 (95% CI 0.24-11.36) for low-dose propranolol (1 mg/kg/day), 1.42 (95% CI 1.12-1.80) for medium dose (2 mg/kg/day) and 1.46 (95% CI 1.17-1.82) for high dose (3 mg/kg/day), but the high dose had higher adverse events rate than medium dose, with 3.60% and 86.22%, respectively. The effectiveness of propranolol therapy among cases of treatment duration less than 6 months (RR = 1.24, 95% CI 1.05-1.47) was inferior to that of treatment duration greater than or equal to 6 months (RR = 1.46, 95% CI 1.11-1.92).

CONCLUSIONS

This meta-analysis reveals that oral propranolol is superior to other treatments in improving response rate of IH and can be used as the first-line therapy for IH children. A dosage of 2 mg/kg/day propranolol orally may be a good choice for IH. However, further studies are essential.

The Influence of Formulation and Excipients on Propranolol Skin Permeation and Retention

The objective of this work was to study in vitro propranolol permeation and skin retention after topical application of different semisolid vehicles, with the final aim of developing new topical formulations intended for the treatment of infantile hemangioma, able to produce therapeutic drug levels in the skin, avoiding systemic absorption. Propranolol ointments, creams, and gels were prepared and tested on pig skin, an accepted model of human skin. From the results obtained in the present work it is clear that the permeation of propranolol across the skin is a poor predictor of its skin retention, at least in the time-frame considered. With an application time of 4 h, reasonably close to the permanence time of a semisolid formulation on the skin surface, the best performance (high retention and low skin penetration) was obtained with lipophilic formulations, in particular with a lipophilic cream containing olive oil. Hydrophilic formulations, such as gels, are characterized by a significant permeation across the skin, probably leading to systemic side effects, accompanied by a limited skin retention. Overall, the results obtained in the present work pose the basis for the development of new topical formulations, containing propranolol, with better performance and reduced systemic absorption.