Comparative effects of various calcium entry blockers and anti-asthmatic compounds on antigen-induced bronchoconstriction in rat and histamine release from rat mast cells

Effects of inhaled glaucine on pulmonary responses to antigen in sensitized guinea pigs

The alkaloid (S)-(+)-1,2,9,10-tetramethoxyaporphine (glaucine) is a phosphodiesterase 4 inhibitor with bronchodilator and anti-inflammatory activity in vitro. In this study, we examined the in vivo effects of glaucine on an animal model of asthma. In ovalbumin sensitized guinea pigs, inhaled glaucine (10 mg ml(-1), 3 min) inhibited the acute bronchoconstriction produced by aerosol antigen (antigen response was 256+/-42 and 95+/-14 cm H(2)O l(-1) s(-1) in control and glaucine-treated animals, respectively; P<0.05). Pretreatment with glaucine (10 mg ml(-1), 10 min inhalation, 30 min pre- and 3 h post-antigen exposure) markedly reduced airway hyperreactivity to histamine, eosinophil lung accumulation, and increased eosinophil peroxidase activity in bronchoalveolar lavage fluid 24 h after exposure of conscious guinea pigs to aerosol antigen. In addition, inhaled glaucine (5-10 mg ml(-1), 3 min) inhibited the microvascular leakage produced after inhaled antigen at all airway levels. These data support the potential interest of phosphodiesterase 4 inhibitors in asthma treatment.

Therapy of chronic idiopathic urticaria with nifedipine: demonstration of beneficial effect in a double-blinded, placebo-controlled, crossover trial

The efficacy of nifedipine, a calcium channel antagonist, in the treatment of chronic idiopathic urticaria, was evaluated in a double-blinded, placebo-controlled, crossover trial. Ten patients with chronic urticaria refractory to maximally tolerated doses of H1 and H2 antihistamines and in whom extensive evaluation failed to identify a cause for their urticaria were entered into the study. Patients continued with their prestudy antihistamine regimens. A study drug dosage was titrated in each patient and maintained throughout the trial. Patients were treated with placebo or nifedipine for 4 weeks and then crossed over to the other medication for 4 weeks. One patient withdrew because of unrelated medical illness, two patients withdrew after crossover to placebo because of intolerable urticaria, and seven patients completed the study. A beneficial effect of nifedipine was clearly demonstrated. Hive count, hive index, and itch index were all significantly improved at the end of 4 weeks of nifedipine treatment (p = 0.023, 0.003, and 0.003, respectively) but not placebo treatment (p = 0.194, 0.664, and 0.944, respectively). Additionally, end point hive index and itch index scores with nifedipine compared to corresponding placebo scores were significantly improved (p = 0.010 and 0.008, respectively). Nifedipine was well tolerated. Thus, when nifedipine is used as an adjunct to antihistamines, it appears to be a safe, efficacious drug for the treatment of chronic idiopathic urticaria.

Effect of ketotifen on adriamycin toxicity: role of histamine

The effect of ketotifen, an antianaphylactic drug which acts in part similarly to sodium cromoglycate, was tested on adriamycin-induced histamine release and toxicity. The intraperitoneal injection of various concentrations of ketotifen induced an important histamine release from rat mast cells. Thirty minutes after the injection, however, no more histamine was present in the peritoneum. When i.p. administered to mice 30 min before adriamycin (15 mg/kg), ketotifen significantly ameliorated the survival time and reduced the cardiotoxicity. On the contrary, when given simultaneously, the antiallergic drug increased the toxic effect of adriamycin.