OTIX

Polymixin B is bactericidal against a wide range of gram negative bacilli. It exerts a bactericidal effect by binding to acid phospholipids in the cell wall and membranes of the bacterium, thereby rendering ineffective the osmotic barrier normally provided by the cell membrane.

Trimethoprim is a dihydrofolate reductase inhibitor, inhibiting the conversion of bacterial dihydrofolic acid to tetrahydrofolic acid, required for the synthesis of some amino acids. Its effects are considerably greater on the cells of micro-organisms than on the mammalian cells.

Dexamethasone is a synthetic glucocorticoid; it combines high anti-inflammatory effects with low mineralocorticoid activity. It has an approximately 7 times greater anti-inflammatory potency than prednisolone, another commonly prescribed corticosteroid. At high doses it reduces the immune response.