Drug-drug Interactions in Icu

Protein Binding One of the most important factors in drug-drug interactions is the plasma protein concentration, specifically albumin. Albumin is the major protein responsible for binding acidic drugs such as warfarin, NSAIDS and anticonvulsants. Decreases in albumin level, which are commonly seen with critical illness, can lead to an excess of unbound, and therefore more active, drug. Alpha1-acid glycoprotein (AAG) is the major protein responsible for binding basic drugs such as lidocaine, propanolol and amytriptyline. As AAG is an acute-phase protein, levels can increase in acute illness and therefore inhibit the actions of these medications.