Usually antiobiotics are prescribed early on, and unlike antibiotic use in healthy individuals, CF patients use them long term and at higher doses. A variety of bacteria can infect the lungs of a patient with CF and an assortment of antibiotics can be prescribed. Selecting an appropriate antibiotic is based on a sputum culture. Sputum is the substance that is expelled from the body when a person coughs or clears his or her throat. A sputum culture involves examining the cells of the sputum under the microscope to identify bacteria.
More severe infections require intravenous administration.
Infection by Pseudomonas auriginosa , for example, another bacterium commonly found in the lungs of CF patients, usually requires intravenous treatment. Acute antibiotic treatment is usually prescribed from 10 to 21 days. One of the major problems with repeated antibiotic therapy is the risk that the microorganisms will evolve into resistant forms that are no longer affected by the antibiotic. Two bacteria in particular, Burkholderia cepacia and Stenotrophomonas maltophilia , are occasionally highly drug resistant. CF patients or their caretakers should ask their physicians about vaccinations against pneumococcal infection and annual influenza vaccination.