Doxycycline belongs to the group of tetracyclines and acts bacteriostatic against
many Gram-positive and Gram-negative bacteria, like Bordetella, Campylobacter,
E. coli, Haemophilus, Pasteurella, Salmonella, Staphylococcus and Streptococcus spp. Doxycycline is also active against Chlamydia, Mycoplasma and Rickettsia
spp. The action of doxycycline is based on inhibition of bacterial protein synthesis.
Doxycycline has good affinity towards the lungs and is therefore especially useful
for treatment of bacterial respiratory infections. Gentamicin sulphate belongs to
the group of aminoglycosides and acts bactericidal against mainly Gram-negative
bacteria, like E. coli, Klebsiella, Pasteurella and Salmonella spp. The bactericidal
action is based on inhibition of bacterial protein synthesis as well. Administered orally, gentamicin is poorly resorbed and, therefore, performs its action
predominantly in the gastrointestinal tract.
Bromhexine is mucolytic (sekretolitychnyy) and expectorant effects. Mucolytic
effect is associated with depolymerization and watering mukoproteyinovyh
mukopolisaharydnyh and fiber, which improves separation of sputum, thus making
it easier to breath. One of the important features of the action of bromhexine is its
ability to stimulate the formation of surfactant – a mixture of surfactant lipid-protein-mukopolisaharydnoyi nature, which is synthesized in the cells of the alveoli.
Biosynthesis of surfactant is disturbed in different diseases of the respiratory
system, caused by Mycoplasma gallisepticum, Mycoplasma synoviae, Ornithobacterium rhinotracheale. This leads to disruption of the stability of the alveolar cells,
weakening their reactions to adverse effects.