*1.2.2 The role of medications*

In patients with cystic fibrosis, abnormal functions of oxidases and P450, CYP2C8, CYP2C9, and CYP3A4 cytochromes are observed. The dose of beta-lactam should be reduced by 20%. The doses of aminoglycosides should be decided upon depending on the level of the medication in the blood serum. Increased microsomal metabolism relating to theophylline and methylxanthine through the affected first phase of the biotransformation of the medications. Increased hepatic clearance of the second phase, which may be reflected in the abnormal metabolism of furosemide, lorazepam, and ibuprofen [30–32].
