Doxycycline is a semi-synthetic antibiotic of a broad spectrum of tetracyclines. Causes bacteriostatic action by suppressing protein synthesis of pathogens as a result of blocking the aminoacyl transport RNA (tRNA) with the "information RNA (rRNA) complex" ribosome.

Feldene - the drug used for treatment of inflammatory and degenerative diseases of musculo-skeletal system. NSAIDS, renders antiinflammatory, analgestic, antiaggregant and febrifugal action. Not selectively suppresses COX1 and COX2. The analgetic effect is observed in 30 min. after peroral intake, the antiinflammatory effect occurs by the end of the 1 (first) week of treatment by Feldene. After a single dose of Feldene it acts during 24 h.