Nasal irrigation for drug delivery in adults.

Nasal irrigations are a longstanding modality of treatment. Mechanical nasal lavage and irrigation of the nasal cavities and paranasal sinuses are frequently conflated under the principle of nasal irrigations even if the objectives are different. The aims and principles of these two different modalities are described in the first part of the paper. In the second part, the literature is summarized based on the data related to the clinical efficacy of the nasal irrigation and on the results of the studies assessing the physical efficacy of the delivery. Although abundant, the literature does not provide strong enough evidence about the optimal nasal irrigation modality. There is a genuine need for a clear definition of terms and evidence-based recommendations on the techniques that should be proposed to patients according to specific clinical objectives. The authors proposed a new terminology to distinguish between nasal clearance irrigation and nasal drug irrigation.