Study	Reason for exclusion
Gananca 1973	Randomised, double‐blind, placebo‐controlled trial. Acute sinusitis diagnostic criteria did not fulfil inclusion criteria for this review (clinical symptoms and signs and bacteriologic criteria).
Gananca 1977	Randomised, double‐blind, placebo‐controlled trial. Acute sinusitis diagnostic criteria did not fulfil inclusion criteria for this review (clinical symptoms and signs and bacteriologic criteria).
Hadley 2010	Prospective, multicentre, placebo‐controlled, randomised, double‐blind phase IIIb clinical trial. Acute sinusitis diagnostic criteria did not fulfil inclusion criteria for this review (clinical symptoms and signs, confirmed by radiography; analysis only performed for participants with positive sinus culture).
Hansen 2000a	Randomised, double‐blind, placebo‐controlled trial. Acute sinusitis diagnostic criteria did not fulfil inclusion criteria for this review (clinical symptoms (maxillary pain) and raised values of either C‐reactive protein or erythrocyte sedimentation rate.
Haye 1998	Randomised, double‐blind, placebo‐controlled trial. Acute sinusitis diagnostic criteria did not fulfil inclusion criteria for this review (exclusion of participants with empyema (defined as complete opacity or an air‐fluid level, or a mucosal thickness of 6 mm or more as measured at the upper lateral border of the maxillary sinus)).