Drugs affecting clearance of middle ear secretions: a perspective for the management of otitis media with effusion

Otitis media with effusion (OME) is characterized by the production and accumulation in the middle ear of mucus secretions, whose physicochemical properties are an important feature in the etiology and treatment of the disease. Many types of pharmaceutical agents, including anti-inflammatory agents, antihistamines, antibiotics, and mucolytics, have been used in attempts to improve the clinical status of patients with OME. This study critically reviews the literature from the point of view of possible changes induced by these agents in the physicochemical properties of the secretions and hence their clearance from the middle ear. In vitro studies on mucociliary clearance of respiratory (tracheobronchial) secretions and middle ear effusions are cited as the basis for analyzing the important parameters expected to govern middle ear clearance and to determine the rationale for use (or nonuse) of various classes of drugs. It is expected that this analysis will prove useful in the design of properly controlled trials of such agents.

Effects of the parasympathomimetic drug methacholine and its antagonist atropine on mucociliary activity

The effect on the mucociliary (m.c.) activity of the parasympathomimetic drug methacholine and its antagonist atropine was studied with the aid of a newly developed animal test model, designed for evaluating the effect of pharmacological substances on the m.c. wave frequency. Methacholine i.a. (0.01-2 micrograms/kg) was found to give a dose-dependent acceleration of the m.c. wave frequency, and the threshold dose 0.03 +/- 0.02 (+/- S.D.) micrograms/kg is suggested to be within physiological limits. The anticholinergic drug atropine i.a. (0.05-0.5 mg/kg) did not influence the basal m.c. wave frequency, but a dose of 0.2 mg/kg reduced or abolished the responses to methacholine (0.05-2 micrograms/kg). These results indicate that the basal m.c. activity functions independently of parasympathetic activity in anesthetized animals, that parasympathomimetic drugs influence the m.c. activity and that the effects of these drugs can be reduced or blocked by atropine.