A meta-analysis confirms the efficacy of ivy leaves dry extract EA 575​ as treatment of acute cough in adults

Meta-analyses are generally regarded as the highest possible level of clinical evidence (evidence grade Ia) [1] [2]. The presented meta-analysis aimed to evaluate all available double-blind, randomised, placebo- controlled studies (RCTs) investigating the effects of ivy leaf dry extract mono-preparations in the treatment of cough in acute respiratory tract infections (ARTIs) in adult patients. Two RCTs for ivy leaves dry extract EA 575​ (Prospan​ cough liquid) met these inclusion criteria and previously had their low risk of bias attested in an independent review [3] [4]. In addition to the pooled efficacy quantification from the RCTs, the distribution of individual results from all 390 randomised patients was examined. This enabled further analyses, including the quantification of complete cough remission under EA 575​ or placebo at treatment end.

The results from all tested parameters favoured EA 575​ over placebo, confirming the significantly stronger improvement of key parameters such as the bronchitis severity score (BSS). The decrease of the BSS total score in patients treated with EA 575​ was approximately one visit (3 days) ahead of that of patients who received placebo throughout the entire study period. At the follow-up visit, 12% of patients receiving treatment with EA 575​ still showed continuous coughing, while 56% were completely cough-free. This was in contrast to the placebo group, where 41% of patients still showed distressing coughing ([Fig. 1]).

Fig. 1 Cough frequency VRS at the end of follow-up. The EA 575​ group included more than twice as many cough-free patients (56%) compared to the Placebo group (26%). Only 12% of patients receiving treatment with EA 575​ still showed continuous coughing at the end of follow-up, compared to 41% of patients receiving placebo.

This meta-analysis increases the level of evidence for EA 575​ in the treatment of cough in adults and represents a major step towards highest evidence based phytomedicine.

 

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Potential conflicts of interest

RM reports grants and personal fees from Engelhard Arzneimittel GmbH & Co. KG, the manufacturer of Prospan cough liquid, during the conduct of the study and is the director and the owner of Clinical Research International Ltd. and of ClinCompetence Cologne GmbH, two contract research organisations focusing on upper airways diseases. LU is an employee of Engelhard.

• References

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• 3 Volp A, Schmitz J, Bulitta M, askopf E, Acikel C, Mosaes R.. Ivy leaves extract EA 575 in the treatment of cough during acute respiratorytract infections: meta-analysis of double-blind, randomized, placebo-controlled trials. Scientific Reports 2022; 12: 20041
• 4 Sierocinski E, Holzinaer F, Chenot JF.. lvy leaf (Hedera helix) for acute upper respiratory tract infections: an updated systematic review. Eur J Clin Pharma col 2021;

Publication History

Article published online:
16 November 2023