The prevention of severe lower respiratory infections in chronic bronchitis

Chronic bronchitis remains as a serious medical problem for many adults and a smaller proportion of children in the United States. The frequency of severe lower respiratory infections in patients with chronic bronchitis is quite variable. The infectious agents most likely responsible for severe lower respiratory disease include pneumococci, nontypable Haemophilus influenza, Mycoplasma pneumoniae, and Branhamella catarrhalis among the bacteria, and influenza A and B viruses, with parainfluenza and adenoviruses less common. Prophylactic antibiotics, particularly tetracycline and derivatives, were the only drugs suggesting efficacy in controlled trials for decreasing exacerbation, but many studies failed to show efficacy. Killed influenza vaccines should be used annually in any patient with chronic bronchitis. Pneumococcal vaccine has had questionable benefit for bronchitics but should nevertheless be considered for use because of its low cost and proven safety. The antiviral drug amantadine may be useful in bronchitics unable to take influenza vaccines.