Fixed combinations of acetylcysteine + ambroxol and ambroxol + loratadine occupy an important place in treatment of respiratory system diseases. From clinical pharmacology point of view, feasibility of prescribing these combinations is due to complementary synergistic action of their components and targeted effects on main pathogenesis of respiratory diseases. Use of combinations can improve a function of external respiration, reduce cough and shortness of breath, increase ABT effectiveness, provide additional pleiotropic effects (anti-inflammatory, antioxidant, detoxification, surfactant-saving).