Therapeutic management of cystic fibrosis

The therapeutic management of patients with cystic fibrosis (CF) is reviewed. CF is an autosomal-recessive genetic disease that affects all exocrine glands. Drug therapy is directed toward the relief of symptoms and prevention of complications. Chronic respiratory tract infections and pancreatic insufficiency are the major manifestations. The replacement of pancreatic enzyme is best achieved with microencapsulated preparations. The dose of enzymes is increased until a maximum effect on decreasing steatorrhea is observed. Pseudomonas aeruginosa and Staphylococcus aureus are the most common pathogens in respiratory infections, which usually require 2-3 weeks of inravenous antibiotic therapy. Because patients with CF often have rapid clearance of both penicillins and aminoglycosides and altered apparent distribution volumes of aminoglycosides, individualized dosing is required. The role of prophylactic antibiotic therapy is controversial, since prolonged exposure to antimicrobials may hasten the development of mucoid strains. Aerosolized antibiotics have not been consistently useful in treating these patients, and there is no convincing evidence to support their long-term use. There are also no clear data to support the use of oral or aerosolized mucolytic agents. The inability to deliver the drug to the site of action plus the time and expense of inhalation equipment may only complicate the drug therapy while producing little benefit. Bronchodilators can be useful in improving pulmonary function. Vitamin supplementation with both the fat- and water-soluble vitamins is important in the treatment of CF. Iron supplementation may also be necessary. Until the basic defect in CF is discovered, the use of antibiotics and replacement of pancreatic enzymes will continue to be the mainstay of therapy.