The effect of ramatroban (BAY u 3405), a thromboxane A(2) receptor antagonist, on nasal cavity volume and minimum cross-sectional area and nasal mucosal hemodynamics after nasal mucosal allergen challenge in patients with perennial allergic rhinitis

The thromboxane: A, receptor antagonist, ramatroban (BAY u 3405), was orall y administered for 4 weeks at a daily dose of 150 me (b.i.d.) to 10 patient s with perennial allergic rhinitis who had a positive reaction to house dus t challenge on nasal mucose. Nasal cavity volume and minimum cross-sectiona l area were measured, and changes in nasal mucosal swelling were determined following, allergen challenge with house dust. The influence on nasal muco sal hemodynamics was also investigated. Nasal cavity volume and minimum cro ss-sectional area were measured by acoustic rhinometry, and blood Row in th e nasal mucosa was measured by laser Doppler flowmetry. Percent changes in values from baseline nasal cavity volume were significantly decreased by al lergen challenge before ramatroban administration, but no significant decre ase was noted after ramatroban administration. Similarly, percent changes i n values from baseline nasal cavity minimum cross-sectional area were signi ficantly decreased by allergen challenge before administration of ramatroba n, but not after administration. Percent changes in values from baseline na sal mucosal hemodynamics were significantly increased by allergen challenge both before and after ramatroban administration, which thus had no effect on mucosal hemodynamics. These findings suggest that ramatroban might inhib it the increase in nasal mucosal swelling but has no effect on nasal mucosa l hemodynamics.