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.

Tetracycline has a wide range of antibacterial activity. It interferes with the formation of a complex between the transport RNA and the ribosome, which leads to a violation of protein synthesis by a microbial cell. Active in relation to most gram-positive and gram-negative bacteria, spiophets, leptospires, rickettsiaes, trachomae pathogens, ornithosis, and large viruses.

Sumycin - An antibiotic based on tetracycline, a brand of such pharmaceutical companies as Bristol-Myers Squibb, Apothecon, Par Pharmaceutical.

Doryx MPC (doxycycline hyclate) delayed-release tablets for oral use, contain doxycycline hyclate, a tetracycline class drug synthetically derived from oxytetracycline, in a delayed-release formulation consisting of pellets with a modified polymer enteric coat that has increased acid resistance.

Antibiotic with antitumor activity obtained from the Streptomyces caespitosus fungus. It inhibits DNA synthesis, in high concentrations it inhibits the synthesis of protein and RNA. Has a relatively weak immunosuppressive activity.

The drug therapeutic indications include: esophageal cancer, stomach cancer, pancreatic cancer, liver cancer, cancer of the bile ducts, cancer of the colon and rectum, breast cancer, cervical cancer, endometrial cancer, vulvar cancer, non-small cell lung cancer, mesothelioma, cancer of the renal pelvis and ureter, bladder cancer, prostate cancer, malignant tumors of the head and neck, chronic myelocytic leukemia.