- Impair production of bacterial nucleic acids - RNA & DNA (some antifungals, quinolones) CAUTION as these can also attack mammalian DNA Lipophilic Drugs - Definition Drugs that more easily move across phospholipid cell membranes and into places such as the brain, eyes and prostate Hydrophilic Drugs - Definition Drugs that finid it more difficult to penetrate the cell membranes Cross Resistance -