Background: Pelargonium sidoides (P. sidoides), also known as Umckaloabo, is a herbal remedy thought to be effective in the treatment of acute respiratory infections (ARIs).
Objectives: To assess the efficacy and safety of P. sidoides for the treatment of ARIs in children and adults.
Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 4) which includes the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1966 to November 2007); EMBASE (1974 to December 2007); and other electronic databases.
Selection criteria: Randomized controlled trials (RCTs) examining the efficacy of P. sidoides preparations in ARIs compared to placebo, no treatment or any other treatment. Complete resolution of all symptoms was defined as a primary outcome.
Data collection and analysis: Three review authors (AT, JG, WK) independently extracted and quality scored the data. Separate analyses were performed by age group and disease entity. Heterogeneity was examined using the I-square (I(2)) statistic. Pooled relative risks (RR) were calculated using a fixed-effect model if heterogeneity was absent (I(2) < 5%; P > 0.1), or a random-effects model in the presence of heterogeneity. If heterogeneity was substantial (I(2) > 50%; P < 0.10), a pooled effect was not calculated.
Main results: Three trials (746 patients) of efficacy in acute bronchitis in adults showed substantial heterogeneity for all relevant outcomes. and three trials (819 children) were similarly inconsistent for acute bronchitis in children. Type of preparation was a potential cause of heterogeneity (not effective in tablet form). One unpublished study in patients with sinusitis (n = 103 adults) showed significant treatment effects (complete resolution at day 21; RR 0.43, 95% CI 0.30, 0.62). One study in the common cold demonstrating efficacy after 10 days, but not five days. Four trials were excluded because of excessive risk of bias. There were no valid data for the treatment of other acute respiratory tract infections. Adverse events were more common with P. sidoides, but none were serious.
Authors' conclusions: P. sidoides may be effective in alleviating symptoms of acute rhinosinusitis and the common cold in adults, but doubt exists. It may be effective in relieving symptoms in acute bronchitis in adults and children, and sinusitis in adults. Reliable data on treatment for other ARIs were not identified.