Oxytetracycline, whose chemical formula is C22H24N2O9, belongs to the tetracycline group. It is a yellow crystalline powder that is easily soluble in water and is acidic. It is a broad-spectrum semi-synthetic antibiotic that is antibacterial rather than bactericidal.
Oxytetracycline has a broad-spectrum anti-pathogenic microorganism effect, is a fast antibacterial agent, and has a bactericidal effect on certain bacteria at high concentrations. The mechanism of action is that the drug can specifically bind to the A position of the 30S subunit of the ribosome to prevent the linkage of aminoacyl-tRNA at this position, thereby inhibiting the growth of peptide chains and affecting the protein synthesis of bacteria or other pathogenic microorganisms. Oxytetracycline is more effective against Staphylococcus aureus, pneumococcus, Streptococcus pyogenes, Neisseria gonorrhoeae, meningococcus, Escherichia coli, Aerobacter, Shigella, Yersinia, Listeria monocytogenes, etc. Strong antibacterial activity; in addition, oxytetracycline also has a strong effect on rickettsia, mycoplasma, chlamydia, actinomycetes, etc.
The oral absorption of oxytetracycline hydrochloride is incomplete (about 30%-58% can be absorbed), and the volume of distribution is about 0.9-1.9L/kg. The peak blood concentration after a single oral dose of 1 g is about 3.9 mg/L. The drug is widely distributed after absorption, and can penetrate into the pleural effusion and abdominal effusion, and can also enter the blood circulation of the fetus through the placental barrier, but it is not easy to penetrate the blood-cerebrospinal fluid barrier, so the concentration of the drug in the cerebrospinal fluid is low. Oxytetracycline can also be distributed in the liver, spleen, bone marrow, bones, dentin and tooth enamel. The drug can also reach higher concentrations in milk. The binding rate of oxytetracycline protein is about 20%-35%. The half-life of patients with normal renal function is 6-10h, and the half-life of renal insufficiency is prolonged, and it can reach 47-66h for anuria. The drug is mainly excreted through glomerular filtration, and 70% of the dose can be excreted within 24 hours of administration, and a small amount of drug is excreted through feces via bile. Hemodialysis can remove 10%-15% of the drug.


Indications
1. Oxytetracycline can be used as a drug of choice for the treatment of the following diseases:

(1) Rickettsia, including epidemic typhus, endemic typhus, and tsutsugamushi;

(2) Infection caused by Mycoplasma pneumoniae;

(3) Chlamydia infections, including psittacosis, inguinal granuloma (lymphgranuloma venereal disease), non-specific urethritis, salpingitis and trachoma;
(4) Relapsing fever;

(5) Brucellosis (combined with aminoglycoside drugs);

(6) Cholera;

(7) Plague (in combination with aminoglycoside drugs);

(8) Tularemia.

2. Oxytetracycline can be used to treat tetanus, gas gangrene, yaws, syphilis, gonorrhea and leptospirosis that are allergic to penicillin antibiotics.

3. Oxytetracycline can also be used to treat respiratory tract, biliary tract, urinary tract and skin and soft tissue infections caused by sensitive bacteria.

4. Oxytetracycline can also be used for acne treatment.