Endocarditis prophylaxis: do patients remember advice and know what to do?

Time (minutes) Mean (SEM) changes in forced expiratory volume in one second, expressed as percentage of baseline value, after inhalation of hypotonic sodium bromide solution (-), isotonic sodium bromide solution (@), isotonic sodium chloride solution (*), and isotonic ipratropium bromide nebuliser solution (A).forced expiratory volume in one second (24-0 (SEM 5 3)%) occurring two minutes after inhalation (p<001).Inhalation of the three remaining test solutions produced no significant change in airway calibre (figure 1). CommentIn this study bromide ions administered in the form of isotonic sodium bromide or isotonic ipratropium bromide did not produce significant bronchoconstriction in asthmatic patients who had previously developed bronchoconstriction after inhaling the original hypotonic ipratropium bromide nebuliser solution.The only solution that produced broncho- constriction was the hypotonic sodium bromide, which had no effect on airway calibre when made isotonic.The patient reported on by Patel and Tullett developed bronchoconstriction in response to ipratropium bromide and sodium bromide dissolved in isotonic saline,5 and this response was probably due to an idiosyncratic reaction to bromide ions.As none of the nine patients in the present study developed such a response it seems an unlikely explanation for the bronchoconstriction observed with the previously marketed ipratropium bromide, and we conclude that the major problem was hypotonicity of the solution.The current preparation of ipratropium bromide available for nebulisation is isotonic, which therefore circumvents the original problem of bronchoconstriction induced by hypotonicity.We are grateful to Dr Sarah Morgan of Boehringer Ingeiheim for advice during the preparation of the protocol and for supplying the nebuliser solutions.1 Connolly CK.Adverse reaction to ipratropium bromide.BrMedJ 1982;285:934-5.2 Jolobe OMP.Adverse reaction to ipratropium bromide.BrMedJ7 1982;285:1425-6.3 Schoeffel RE, Anderson SD, Altounyan RE.Bronchial reactivity in response to inhalation of ultrasonically nebulised solutions of distilled water and saline.Br Med 7 1981;283:1285-7.4 Mann JS, Howarth PH, Holgate ST.Bronchoconstriction induced by ipratropium bromide in asthma: relation to