A comparison of the effects of an alpha-agonist, an anti-muscarinic agent and placebo on intranasal histamine challenge in allergic rhinitis

Role of parasympathetic nerves and muscarinic receptors in allergy and asthma

Parasympathetic nerves control the symptoms and inflammation of allergic diseases primarily by signaling through peripheral muscarinic receptors. Parasympathetic signaling targets classic effector tissues such as airway smooth muscle and secretory glands and mediates acute symptoms of allergic disease such as airway narrowing and increased mucus secretion. In addition, parasympathetic signaling modulates inflammatory cells and non-neuronal resident cell types such as fibroblasts and smooth muscle contributing to chronic allergic inflammation and tissue remodeling. Importantly, muscarinic antagonists are experiencing a rebirth for the treatment of asthma and may be useful for treating other allergic diseases.

Techniques d’étude pharmacologique et clinique de l’obstruction nasale : application à la xylométazoline

Nasal obstruction, a prominent feature of rhinitis, may be quantified in humans by haemodynamic techniques (measuring local blood flux), static methods (measuring the geometry of nasal cavities) and dynamic methods (assessing the patency of nasal airways through the measure of resistance to air flow). These methods demonstrated the nasal decongestant activity of xylometazoline in healthy volunteers and rhinitis patients. Controlled double-blind studies established the clinical efficacy of xylometazoline in infectious and allergic (seasonal and perennial) rhinitis versus placebo and in comparison with various reference substances. The effects on nasal epithelium ciliary activity which are observed in vitro are modest and even less pronounced in vivo owing to dilution in situ and protective physiological processes.

Comparison of the clinical efficacy of standard and mucoadhesive-based nasal decongestants

AIMS

To compare two xylometazoline 0.1% preparations: reference commercial solution (RS) and test mucoadhesive solution (TS).

METHODS

Twenty subjects with perennial allergic rhinitis (age range 18-69 years, 5 atopic, 7 men) applied randomly in turn TS and RS for 5 days in a double-blind crossover clinical trial. Nasal airflow resistance (NAR), nasal symptoms (6 grade scoring), frequency of application (times/day), and side-effects were recorded.

RESULTS

Mean ratio TS/RS of areas under the resistance/time curves for NAR +/- 90% CI: 3.56 +/- 0.92; mean TS-RS differences +/- 95% CI: for congestion: -1.12 +/- 0.59, for frequency of application: -1.10 +/- 0.20. Subjects experienced fewer side-effects with TS.

CONCLUSIONS

A mucoadhesive solution with a decongestant had a greater and longer lasting effect on nasal congestion in subjects with perennial allergic rhinitis than the commercially available decongestant solution. It also caused fewer side effects.