The Efficacy of Oral Phenylephrine as a Decongestant: A Systematic Review

Abstract

Background: Phenylephrine (PE) is a non-prescription decongestant listed on the Australian Register of Therapeutic Goods (ARTG). However, there are no published systematic reviews supporting the efficacy and safety of this product for this use. Objective: This review examine the efficacy of oral PE as a nasal decongestant for patients aged over 12 years with symptoms of nasal congestion (i.e., allergic rhinitis, influenza-like illness). Methods: PubMed, EMBASE and the Cochrane Central Registry of Controlled Trials were searched for English and non-English studies published through December 2020 that measured the efficacy of phenylephrine in patients with nasal congestion. Studies included in the analysis were randomised, placebo-controlled trials measuring the effects of phenylephrine. Combination products with phenylephrine and other active decongestants were excluded. Two investigators independently extracted data on nasal airway resistance (NAR), self-reported decongestant scores and adverse reactions from each of the included studies. Continuous outcomes including nasal airway resistance and symptom reduction were analysed using weighted mean differences; or standardised mean differences if different measurement scales were used. Results: Three randomised placebo trials evaluating the efficacy and safety of phenylephrine were included for analysis. All three studies demonstrated no statistically significant improvement with PE compared with a placebo in their self-reported symptom scores and in or rhinomanometry results. There was significant heterogeneity among the studies included in this analysis, which was attributed due to different methodologies and scoring systems used. Because of this summarising primary endpoint results was not possible. Conclusions: There is no evidence that phenylephrine is effective for non-prescription use as a nasal decongestant. This is in congruence with previous reviews like Hatton et al. Based on this review, we recommend that the Therapeutic Goods Administration (TGA) review the efficacy and safety of this common ingredient in decongestant products.