Design and discovery of RWJ 22108--a novel bronchoselective calcium channel blocker.

A series of cyclic sulfone dihydropyridines ranging in sulfone ring size from five to nine membered have been evaluated for calcium antagonist activity. Increasing the sulfone ring size from 5 to 8 membered resulted in a two orders of magnitude in vitro potency increase. Aromatic substitution which favored tracheal effects over aortic effects was found to be 2-NO2 and 2-Cl, 6-F. The ester side chain which was found to maximize in vivo activity was the N-benzyl-N-methyl aminoethyl moiety. Combination of all these structural features resulted in RWJ 22108, a bronchoselective calcium channel blocker which preclinically exhibits an antiasthmatic profile.

Initial and steady-state effects of diphenhydramine and loratadine on sedation, cognition, mood, and psychomotor performance.

BACKGROUND: The classic, first-generation histamine1-receptor antagonists used to treat allergic disorders frequently cause sedation. In contrast, sedation is reduced or absent after administration of recommended doses of second-generation histamine1-receptor antagonists. We measured the initial and steady-state effects of diphenhydramine, a first-generation antihistamine, and loratadine, a second-generation antihistamine, by means of a comprehensive battery of psychometric tests that mirror real-world tasks. METHODS: Healthy volunteers (N = 98) were randomly assigned in a double-blind fashion to receive loratadine (n = 33), diphenhydramine (n = 32), or placebo (n = 33). A computerized test battery was administered at baseline, on day 1 after administration of the initial dose, and on days 3 and 5. RESULTS: After the initial dose, subjects taking diphenhydramine demonstrated poorer cognitive performance than subjects taking loratadine or placebo on tasks of divided attention, working memory, speed, and vigilance. Subjects taking diphenhydramine also reported greater fatigue and sleepiness and lower levels of motivation, and rated the quality of their performance as lower than subjects taking loratadine or placebo. On day 3, subjects taking diphenhydramine continued to show more fatigue and lower motivation, and rated the quality of their test performance as poorer than subjects taking loratadine or placebo. There were no differences between loratadine and placebo after the initial dose or steady-state (day 5) dosing for any measure of cognitive or psychomotor test performance, mood, or sedation. CONCLUSIONS: Patients taking diphenhydramine may be at risk of lapses and significant errors that may lead to potential hazards and decreased work productivity.

RWJ-22108--a novel airway tissue--selective calcium channel blocker.

RWJ-22108 is a novel calcium entry blocker that has potential therapeutic use as an antiasthmatic agent. Although displaying typical potent inhibition of 45Ca uptake into aortic rings (IC50 = 7.1 nM) and displacement of [3H]nitrendipine from cardiac membranes (IC50 = 137 nM), RWJ-22108 demonstrates tissue selectivity in the inhibition of KCl-induced contractions. RWJ-22108 inhibits the calcium-dependent contraction of canine bronchiolar smooth muscle with an IC50 of 5.7 nM. The IC50 femoral artery/IC50 bronchiolar ratios are 2.85, 8.02, 1.47 and 1.96 for nifedipine, RWJ-22108, verapamil, and gallopamil, respectively. Furthermore, this selectivity ratio (range 2.8-5.5) of RWJ-22108 is also observed when inhibition of other pulmonary and cardiovascular smooth muscles are compared. Using canine tracheal muscle and rabbit aortae, the IC50 aorta/IC50 trachea ratio is 1.75 for RWJ-22108 compared to approximately 0.5 for several calcium blocker standards. These results indicate that in vitro RWJ-22108 is a bronchoselective calcium channel blocker.