Doxcolin belongs to the group of tetracyclines and acts bacteriostatic
against many Gram-positive and Gram-negative bacteria. The action of
doxycycline is based on inhibition of bacterial protein synthesis. Doxycycline
has good anity towards the lungs and is therefore especially useful for
treatment of bacterial respiratory infections. Colistin is an antibiotic from the
group of polymyxins with bactericidal action against mainly Gram-negative
bacteria. Polymyxins interact strongly with phospholipids and penetrate into
and disrupt the structure of cell membranes.