Respiratory tract side effects of angiotensin converting enzyme inhibitors: current knowledge

Use of ACE inhibitors and risk of community-acquired pneumonia: a review

BACKGROUND

The administration of angiotensin-converting enzyme (ACE) inhibitors has been suggested as an alternative strategy for lowering the risk of community-acquired pneumonia (CAP) in the elderly, especially in patients with neurological and cerebrovascular comorbidity.

METHODS

We critically examined the relevant data from studies regarding the impact of ACE inhibitors in lowering the risk of CAP and/or mortality due to CAP in the elderly. We searched PubMed, Cochrane Database, and references of initially retrieved articles, and http://clinicaltrials.gov for ongoing trials.

RESULTS

We identified 285 evaluable studies. Fourteen studies met the inclusion criteria and were evaluated further, of which seven were prospective studies, two randomized controlled trials, and five retrospective studies. Eight of ten studies including patients of Asian origin demonstrated a statistical significance in favor of ACE inhibitors. On the contrary, only one of five studies including patients of non-Asian origin demonstrated results in favor of ACE inhibitors.

CONCLUSION

The available data suggest that ACE inhibitors may contribute to the reduction of the risk of CAP. Nevertheless, clinical data are scarce and mainly comprise studies including patients of Asian origin. As there seem to be differences regarding the genetic polymorphism of ACE among patients of different origins, future studies are needed that incorporate relevant genetics data that may help clarify the role, if any, of ACE inhibitors in preventing CAP.

Chronic cough

Chronic cough is a common symptom presenting to all clinicians. Every effort should be made to determine the cause(s) of cough because specific therapy has a higher likelihood of success than empiric therapy. Evaluation begins with a complete history, physical examination, routine health screen laboratory testing, chest film, and pulmonary function testing. Further investigation should be guided by the response to treatment of the most likely diagnostic possibilities: postnasal drip, cough-variant asthma, gastroesophageal reflux, chronic bronchitis, bronchiectasis, and ACE inhibitor induced. The majority of each patient's workup can be performed and ordered by the primary care physician.

Rhinitis as a mechanism of respiratory defense

The incidence of rhinitis is on the increase, especially in towns and cities with high levels of pollution from motor traffic and industry. There is a growing body of evidence which links this increased incidence of rhinitis to chronic nasal irritation from industrial pollution. Studies on the mechanisms of nasal inflammation and the nasal immune response are now providing insights into the etiology of rhinitis. This knowledge will help in the development of therapies aimed at alleviating the symptoms of rhinitis and controlling the development of rhinitis in susceptible individuals. This review discusses some of the factors that may explain the increased incidence of rhinitis and examines basic mechanisms involved in the nasal response to infection and allergy.