[Asthma and antihypertensive treatment]

The respective prevalence of arterial hypertension and of asthma is sufficient that their association is far from unusual. Antihypertensive medications may have deleterious or beneficial effects on the bronchi. Calcium inhibitors oppose the contraction of smooth muscle and the liberation of inflammatory mediators from mast cells. In asthmatics, their acute administration has a modest beneficial effect on spontaneous bronchial obstruction, only exerts a partial protective action against numerous non-specific or allergic stimuli, and weakly reinforces the beneficial effects of beta-2 agonists. The antagonists of beta-adrenergic receptors worsen bronchial obstruction and non-specific bronchial hyperreactivity in asthmatics. These deleterious effects increase with the dose and have been observed even after administration of eye drops and apply to all beta blockers. Inhibitors of angiotensin converting enzymes increase bronchial hyperreactivity in patients developing cough during treatment and may indeed, even in a few cases, trigger an asthmatic attack, probably by opposing the inactivation by hydrolysis of tachykinins and bradykinins. The effects of alpha-2 adrenergics are controversial. Inhaled, they reduce the early allergic bronchial response, even when ingested they aggravate the bronchial response to histamine, all the more so as their effect on the central nervous system is greater. The alpha-1 adrenergic antagonists, frusemide and ketanserin have an overall beneficial effect.