Reviewed: Schapowal A, Berger D, Klein P, Suter A. Echinacea/sage or chlorhexidine/lidocaine for treating acute sore throats: a randomized double-blind trial. Europ J Med Res. 2009;14(9):406-412.

Sore throat is one of the most common ailments in general medical practice. Fewer than 20% of people with a sore throat are infected with Streptococcus (“strep throat”) and require antibiotic treatment, and normal sore throat is typically treated with pain relievers alone. Common over-the-counter drugs for relief of sore throat include analgesics and throat sprays (containing numbing agents or antibacterial ingredients). Echinacea (Echinacea purpurea, Asteraceae) herb and root and common sage (Salvia officinalis, Lamiaceae) leaf have antiinflammatory, antimicrobial, and immune modulating properties and are also used in Europe to relieve sore throat and other symptoms of upper respiratory tract infections. The purpose of this study was to compare the effectiveness of a throat spray containing extracts of echinacea plus sage with a throat spray containing chlorhexidine plus lidocaine in relieving sore throat pain.

This randomized, double-blind, controlled trial was conducted by researchers at the Allergy Clinic in Landquart, Switzerland; D.S.H. Statistical Services GmbH in Rohrbach, Germany; and A. Vogel Bioforce AG in Roggwil, Switzerland. The subjects were recruited from 11 general practice clinics in Switzerland. The subjects were over the age of 12 years, had throat pain for less than 72 hours, and did not have a bacterial throat infection.

The subjects were randomly assigned to receive 1 of 2 throat sprays. The echinacea-plus-sage spray contained aqueous ethanolic extracts of E. purpurea (863.3 mg/ml flowering aerial parts tincture and 45.5 mg/ml root tincture; Echinaforce_® concentrate) and S. officinalis leaves (430 mg/ml leaf tincture). The tinctures were provided by A. Vogel Bioforce AG. The chlorhexidine-plus-lidocaine spray (Collunisol_®; Sanofi AG; Switzerland) contained 1% chlorhexidine (an antiseptic) and 2% lidocaine (a topical anesthetic).

In addition to receiving one of the active sprays, subjects also received a placebo spray. Patients given the echinacea-plus-sage spray received a placebo spray matching the taste, appearance, and smell of the chlorhexidine-plus-lidocaine spray, and vice versa. This doubleplacebo method was used to conceal the identity of the active spray. Subjects were instructed to spray the throat every 2 hours with the active spray and the placebo spray. Subjects continued using the spray until the throat pain was gone, for a maximum of 5 consecutive days. They were also given ibuprofen tablets to take if throat pain was not controlled with the sprays. Subjects were instructed to fill in a daily diary and record how many times they used each spray, how many tablets of ibuprofen they used (if any), and how severe their throat symptoms were, using the Tonsillopharyngitis Severity Score scale. Vital signs were monitored and blood tests conducted to ensure safety at the beginning and end of treatment.

The trial enrolled 154 subjects: 80 allocated to the echinacea-plus-sage group and 74 to the chlorhexidine-plus-lidocaine group. A total of 133 subjects completed the trial according to protocol and were included in the efficacy comparison. The response rate, defined as a 50% reduction in the symptom severity score, was similar for the 2 groups after 3 days of treatment (69.6% in the echinacea-plussage group and 70.3% in the chlorhexidine-plus-lidocaine group). There were no significant differences in response rates between the 2 groups after 1, 2, or 3 days of treatment. The total amount of active spray and placebo spray used during the study was similar between the 2 groups, as was the usage of ibuprofen. Investigators’ and subjects’ overall ratings of the efficacy of the treatment were also similar.

Five adverse events judged by the investigators to be related to the study sprays were reported. These included rash in the mouth, burning sensation and throat dryness in the echinacea-sage group, and tongue swelling and bitter taste in the chlorhexidine-lidocaine group. About 94% of subjects in both groups rated the tolerability of the sprays as good or very good. C-reactive protein (a marker for inflammation) levels decreased in both groups, but all other blood values and vital signs remained the same.

The authors conclude that the throat spray containing echinacea and sage was as effective in reducing sore throat symptoms and as well tolerated as the spray containing chlorhexidine and lidocaine. They suggest that the spray is an effective alternative to oral and spray products containing analgesic and anesthetic drugs. The authors address the possibility that providing ibuprofen to the subjects may have biased the results. However, a subanalysis showed that the results were the same, regardless of whether or not subjects took ibuprofen. 

The authors discuss results of placebo-controlled trials using throat sprays containing either sage or echinacea, but so far there are no trials comparing the combination spray to a placebo spray. They state that no studies are available on the effectiveness of the chlorhexidine-lidocaine spray in sore throat, even though it is one of the leading products in Switzerland for sore throat relief and has been used for almost 50 years in several countries. The authors do not provide any data on the typical course of untreated sore throat in this population. A further study comparing the echinacea/sage throat spray to a placebo spray would contribute substantially to the proof of efficacy and confirm the positive outcome of this first trial.

–Heather S. Oliff, PhD