ObjectivesThe aim of this review is to examine the causes, pathophysiology and experimental models of noninfectious pharyngitis (sore throat). Introduction The causes of sore throat can be infectious (viruses, bacteria, and fungi) or non-infectious, although the relative proportion of each is not well documented. Methods A PubMed database search was performed for studies of non-infectious sore throat. Results and conclusions Non-infectious causes of sore throat include: physico-chemical factors, such as smoking, snoring, shouting, tracheal intubation, medications, or concomitant illness; and environmental factors including indoor and outdoor air pollutants, temperature and humidity, and hazardous or occupational irritants. The pathophysiology underlying non-infectious sore throat is largely uncharacterised, although neurogenic inflammation looks to be a promising candidate. It is likely that there will be individual disposition factors or the coincidence of more than one irritant with possible-up to now unknown-interactions between them. Therefore, experimental models with defined conditions and objective endpoints are needed. A new model using cold dry air to directly induce pharyngeal irritation in humans, with pharyngeal lavage to measure biomarkers, may provide a useful tool for the study of mechanisms and treatment of non-infectious sore throat.

A new onset-of-action model was utilized to distinguish the pharmacologic activity of flurbiprofen 8.75mg delivered in a lozenge from the demulcent effect of the lozenge base. In a randomized, double-blind, placebo-controlled trial, patients with sore throat rated pain on a Sore Throat Pain Intensity Scale before taking one flurbiprofen or placebo lozenge and at frequent (2-minute) intervals over the first hour after treatment. Further ratings of the Sore Throat Pain Intensity Scale and other patient-reported outcomes (difficulty swallowing, swollen throat, pain relief) were obtained at varying intervals over 6 hours. Onset of pharmacologic activity was defined as the median time of first perceived pain reduction if a patient reported clinically meaningful (at least moderate) relief. The conventional method of comparing mean treatment responses at each time point was also implemented. Demulcent action was detected at the first 2-minute assessment. By the new method, 102 flurbiprofen-treated patients were identified as first perceiving pain relief at 12 minutes, compared with >120 minutes by 102 patients using placebo (P<0.001). By the conventional method, mean percentage pain reduction for flurbiprofen 8.75 mg was first significantly differentiated from placebo at 26 minutes (P<0.05). Efficacy of flurbiprofen lozenge was demonstrated for 3.5-4hours on the 4 patient-reported outcomes (all P<0.05 compared with placebo). There were no serious adverse events. This patient-centered onset-of-action model identifies the initiation of pain relief in patients who are definite drug responders, here demonstrating that a flurbiprofen 8.75-mg lozenge provides early relief of sore throat.

Pharyngitis (sore throat) is usually caused by viral infections; therefore, antibiotics are generally not warranted. Flurbiprofen 8.75 mg spray (maximum five doses/day, for three days) provides effective symptomatic relief. ABSTRACTBackground: Viral infections cause most cases of pharyngitis (sore throat); consequently, antibiotics are generally not warranted. However, a treatment targeting pain and inflammation, e.g. a topical non-steroidal anti-inflammatory spray, may be helpful for patients. Objective: To evaluate the efficacy and safety of flurbiprofen 8.75 mg spray. Methods: This randomised, double-blind, parallel group study was conducted at six communitybased clinical research centres in Australia and two in New Zealand. Adults with sore throat due to upper respiratory tract infection (onset four days) took one dose of flurbiprofen (n ¼ 249) or placebo spray (n ¼ 256); after six hours, they could re-dose every three-six hours as required, for three days (max. five doses/day). The primary endpoint was the area under the change from baseline curve in throat soreness from zero-two hours (AUC 0-2h ). The change from baseline in other sore throat symptoms also assessed efficacy. Results: The mean AUC 0-2h for throat soreness was significantly greater with flurbiprofen spray (À1.82; 95% CI: À1.98 to 1.65) compared with placebo (À1.13; 95% CI: À1.27 to 0.99) (P < 0.0001). Significantly greater reductions from baseline were observed with flurbiprofen spray compared with placebo from the first time-points assessed (five minutes for throat soreness/difficulty swallowing, 20 minutes for sore throat pain intensity and 30 minutes for swollen throat) for up to six hours (P < 0.05 for all). There was no significant difference in adverse events between treatment groups during the three-day study. Conclusion: Flurbiprofen spray provides rapid and long-lasting relief from sore throat symptoms, and is well-tolerated over three days.

Amylmetacresol/DCBA throat lozenges provide rapid analgesic effects that last for 2 h, providing ongoing relief long after the lozenge has dissolved. The superior analgesic effects and improvements in functional impairment scores observed with AMC/DCBA throat lozenges translate into pain relief benefits that are clinically meaningful and are thus a suitable OTC treatment option for patients in the self-management of acute sore throat.

BackgroundThe sore throat pain model has been conducted by different clinical investigators to demonstrate the efficacy of acute analgesic drugs in single-dose randomized clinical trials. The model used here was designed to study the multiple-dose safety and efficacy of lozenges containing flurbiprofen at 8.75 mg.MethodsAdults (n = 198) with moderate or severe acute sore throat and findings of pharyngitis on a Tonsillo-Pharyngitis Assessment (TPA) were randomly assigned to use either flurbiprofen 8.75 mg lozenges (n = 101) or matching placebo lozenges (n = 97) under double-blind conditions. Patients sucked one lozenge every three to six hours as needed, up to five lozenges per day, and rated symptoms on 100-mm scales: the Sore Throat Pain Intensity Scale (STPIS), the Difficulty Swallowing Scale (DSS), and the Swollen Throat Scale (SwoTS).ResultsReductions in pain (lasting for three hours) and in difficulty swallowing and throat swelling (for four hours) were observed after a single dose of the flurbiprofen 8.75 mg lozenge (P <0.05 compared with placebo). After using multiple doses over 24 hours, flurbiprofen-treated patients experienced a 59% greater reduction in throat pain, 45% less difficulty swallowing, and 44% less throat swelling than placebo-treated patients (all P <0.01). There were no serious adverse events.ConclusionsUtilizing the sore throat pain model with multiple doses over 24 hours, flurbiprofen 8.75 mg lozenges were shown to be an effective, well-tolerated treatment for sore throat pain. Other pharmacologic actions (reduced difficulty swallowing and reduced throat swelling) and overall patient satisfaction from the flurbiprofen lozenges were also demonstrated in this multiple-dose implementation of the sore throat pain model.Trial registrationThis trial was registered with ClinicalTrials.gov, registration number: NCT01048866, registration date: January 13, 2010.