BACKGROUND: Long-term rhinoflowmetry assesses bilateral nasal flow over 24 hours. In the present study, we evaluated the effects of a standard dose of oxymetazoline topical nasal spray, a widely used over-the-counter drug, on the nasal cycle, since the exact long-term effects, such as the duration of the decongestive effect, are not yet reported. METHODOLOGY/PRINCIPAL: Thirty healthy volunteers received a portable long-term rhinoflowmetry device and applied 22.5 μg oxymetazoline in each nostril. RESULTS: In 90 % of the probands, effects of the nasal spray application could be seen as changes in nasal flow. A decongestive effect could be seen after 18 minutes on average. We found a mean duration of the maximal decongestive effect of four hours. However, it took more than six hours on average until the nasal cycle resumed its normal condition. We did not find significant differences of the effect between probands with a 'classic,' 'in concert' or impaired nasal cycle. In contrast to a substantial interindividual variability, repeated measurements showed that intraindividual variability of the effect of decongestive nasal spray seems to be rather small. CONCLUSION: Long-term rhinoflowmetry, yielding reliable results, is a valuable tool in the assessment of the effects of nasal drugs on the nasal cycle.
BACKGROUND: Long-term rhinoflowmetry assesses bilateral nasal flow over 24 hours. In the present study, we evaluated the effects of a standard dose of oxymetazoline topical nasal spray, a widely used over-the-counter drug, on the nasal cycle, since the exact long-term effects, such as the duration of the decongestive effect, are not yet reported. METHODOLOGY/PRINCIPAL: Thirty healthy volunteers received a portable long-term rhinoflowmetry device and applied 22.5 μg oxymetazoline in each nostril. RESULTS: In 90 % of the probands, effects of the nasal spray application could be seen as changes in nasal flow. A decongestive effect could be seen after 18 minutes on average. We found a mean duration of the maximal decongestive effect of four hours. However, it took more than six hours on average until the nasal cycle resumed its normal condition. We did not find significant differences of the effect between probands with a 'classic,' 'in concert' or impaired nasal cycle. In contrast to a substantial interindividual variability, repeated measurements showed that intraindividual variability of the effect of decongestive nasal spray seems to be rather small. CONCLUSION: Long-term rhinoflowmetry, yielding reliable results, is a valuable tool in the assessment of the effects of nasal drugs on the nasal cycle.