Tilmicosin Coated has strong antibacterial effects, excellent pharmacokinetic characteristics, and can also enhance the immunity of animals. In addition, recent studies have shown that Tilmicosin also has antiviral effects in the prevention and treatment of individual pig diseases. Moreover, there is no cross resistance between it and other commonly used antibiotics in clinical practice, and significant results have been achieved in the clinical treatment of various animal diseases. Compared with Tylosin, it has fewer dosage, longer lasting effects, fewer side effects, lower residual in vivo, and is safe and non-toxic. It is an economical, safe, and effective new type of antibacterial and growth promoting animal medicine commonly used in livestock and poultry. In the current complex and atypical state of animal diseases, it has brought new ideas and methods for clinical medication. Therefore, Tilmicosin will play a more important role in the control of future livestock and poultry diseases, and has broad application prospects.
1、 Mechanism of action
（1） Inhibiting bacterial protein synthesis
Timicoxin is a semi synthetic macrolide antibiotic specifically designed for livestock and poultry. It has a lactone structure with a 16 membered ring, and the hydroxyl groups on the ring are connected to sugars or substituted sugars through glycosidic bonds. The macrocyclic tension is relatively low, resulting in stable properties. Tilmicosin mainly exerts antibacterial effects by inhibiting bacterial protein synthesis. Its reversible binding with 50S ribosomal subunits inhibits the activity of translocatase, affects the displacement process of ribosomes, hinders peptide chain elongation and protein synthesis, and is a growth phase antibacterial agent. Tilmicosin is currently one of the safest antibiotics, partly due to its low toxicity as it does not bind to the 80S ribosome of mammals.
（2） Promote the body's defense function
Tilmicosin has a synergistic bactericidal effect with macrophages. In normal conditions, macrophages present in the alveoli can ingest bacteria, mycoplasma, and other pathogens that accumulate at the site of infection, use their own digestive enzymes to kill the ingested pathogens, and then release so-called antigen immune components from the killed bacteria, transmitting information within lymphocytes and promoting antibody production. However, in reality, some of the bacteria ingested into macrophages have not been killed, and after administration of temicoxacin, it can work together with macrophage digestive enzymes to kill the pathogens. The study also confirmed that the simultaneous infection of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) and Porcine Circovirus Type II (PCV2) causes a decrease in the number of macrophages in the pig body, while reducing their immune function. At this time, administration of temicoxacin can assist macrophages in bringing their immune function closer to normal. Tilmicosin can also inhibit the necrosis of neutrophils, induce cell apoptosis, and prevent inflammation from worsening. In addition, temicoxacin may also serve as an immune mediator to regulate the body's immune function, thereby promoting the body's defense function.
2、 Antibacterial activity
Tilmicosin has strong antibacterial activity and a wide spectrum of antibacterial activity, with inhibitory effects on all Gram positive bacteria and some Gram negative bacteria, mycoplasma, spirochetes, etc. Mainly used to treat infectious diseases caused by sensitive bacteria in animals such as cows, goats, sheep, cows, pigs, and chickens, especially in the treatment of respiratory tract infections in livestock and poultry, the effect is more significant. It has stronger activity against Actinobacteria pleuropneumoniae, Pasteurella hemolysis, Pasteurella multocida, and Mycoplasma of livestock and poultry than Tylosin.
Studies have shown that temicoxacin has an overall better antibacterial effect on 18 common pathogens in livestock and poultry than cephalosporin V. It is particularly sensitive to Listeria, Pasteurella avium, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, Bordetella bronchitis, Actinobacillus pleuropneumoniae, Haemophilus parahaemolyticus, and Mycoplasma gallisepticerae, and has stronger antibacterial activity than cefazolin sodium. However, it shows moderate sensitivity or resistance to some intestinal pathogenic bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Salmonella, and its antibacterial effect is equivalent to or worse than cefazolin sodium. Studies have shown that it has certain antibacterial effects on eight common pathogens of dairy cow mastitis (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus lactiae, Streptococcus lactiae, Escherichia coli, Klebsiella pneumoniae, Proteus, and Nocardia), especially on G+bacteria, with an overall antibacterial effect better than that of cephalosporin V. Its in vitro antibacterial activity against various pathogenic bacteria of bovine mastitis is also better than that of Tylosin.
3、 Clinical applications
Tilmicosin is mainly used in clinical practice to prevent and treat livestock pneumonia (infections such as Actinobacteria pleuropneumoniae and Pasteurella), poultry mycoplasma, mycoplasma, and mastitis in lactating animals.
（1） Clinical application in pigs
The application of Tilmicosin in the treatment of porcine pneumonia is generally prevented and treated through the administration of mixed ingredients. Some studies have shown that the use of tilmicosin to prevent natural infectious pneumonia in pigs can significantly reduce the incidence rate and severity of pneumonia when mixed with feed at the concentration of 200-400 mg/kg for 15 days, which can play a good role in preventing bacterial pneumonia, and can also prevent and treat mycoplasma pneumonia in pigs. The concentration of feed mixed with 100-200 mg/kg has a significant preventive effect on pleuropneumonia caused by Actinobacillus pleuropneumoniae in pigs, and has the effect of increasing daily weight gain.
Researchers have successfully cleared porcine pleurisy (PCP) and porcine reproductive and respiratory syndrome (PRRS) in some pig farms through partial clearance, early weaning, and treatment with temicoxacin. Other researchers believe that temicoxacin has antiviral effects and can be used to control porcine respiratory syndrome (PRDC) associated with porcine reproductive and respiratory syndrome virus (PRRSV) infection, achieving good results.
Research has shown that Mycoplasma hyopneumoniae is the main pathogen causing porcine respiratory syndrome (PRDC), which not only directly damages the body itself, but also enhances the infection of PRRSV. In addition, Mycoplasma hyopneumoniae can reduce the immune function of pigs. In the early stages of Mycoplasma hyopneumoniae infection in pigs, administering temicoxacin can effectively kill Mycoplasma hyopneumoniae, prevent its attachment and proliferation on cilia, and achieve good early treatment effects.
Furthermore, it takes three weeks for the production of Mycoplasma pneumoniae vaccine to produce immune effects. During this period, Mycoplasma pneumoniae may still invade and damage the body. At this time, temicoxacin or Tylosin preparations can be administered as a transitional measure. The clever combination of drugs and vaccines may be an important measure for controlling Mycoplasma hyopneumoniae in the future.
Clinically, it is recommended to administer 200 mg/kg of water to pigs for 5 consecutive days; Mix feed with a concentration of 100-200 mg/kg feed and 200-400 mg/kg feed for prevention, and feed continuously for 21 days.
（2） Clinical application in poultry
In addition to weight gain, Tilmicosin also has the effect of anti infection, reducing incidence rate, reducing pathological damage, improving survival rate, and the effect of preventing respiratory diseases is significantly better than tylosin.
Tilmicosin also has a significant effect on preventing avian Pasteurella infection when administered through drinking water. After entering the chicken body, it has a strong inhibitory and killing effect on Pasteurella.
In addition, Tilmicosin has strong antibacterial activity against avian mycoplasma and has been used to treat avian mycoplasma disease with good results. At the same time, it can effectively reduce the degree of airbag damage caused by artificially induced mixed infections of Mycoplasma gallisepticum and Escherichia coli, and improve feed conversion rate.
Clinically, it is recommended to use continuous water administration for the prevention of respiratory system infections in chickens. The dosage should be greater than or equal to 200 mg/L and should be used continuously for 3-5 days. Administering 100-200 mg/L of drinking water continuously for 5 days can prevent and treat Mycoplasma. In addition, the use of 100 mg/L, 200 mg/L, and 300 mg/L drinking water for the treatment of experimental chicken sepsis mycoplasma disease has good preventive and therapeutic effects.
（3） Clinical application in cattle
Timicoxin injection can effectively treat respiratory diseases caused by Pasteurella multocida, Pasteurella hemolysis type I, and Mycoplasma infections in cattle, and its therapeutic effect is better than that of ampicillin sodium injection. In the application of temicoxacin in beef cattle, subcutaneous injection of 10 mg/kg, 20 mg/kg, and 30mg/kg in single doses can significantly reduce the body temperature of diseased cattle, alleviate clinical symptoms, and alleviate the degree of lung tissue lesions. At the same time, the detection of Pasteurella in bovine lung tissue and the mortality rate of diseased cattle are also significantly reduced.
A comparative study found that when long-acting oxytetracycline (20 mg/kg) and tilmicosin (10 mg/kg) were used to prevent beef cattle pneumonia, they could significantly reduce the incidence rate and mortality of pneumonia and other diseases. Tilmicosin was significantly better than long-acting oxytetracycline in terms of weight gain and symptom relief. Clinically, it is recommended to use subcutaneous injection of 10 mg/kg body weight, once per 3 days (daily injection not exceeding 25 mg/kg body weight).
In the application research of cows, subcutaneous injection of temicoxacin to treat lactating cows with Staphylococcus aureus mastitis can significantly reduce the number of bacteria and somatic cells in milk. Injecting 10 mg/kg under the endothelium or infusing 300 mg/time into the breast during the dry milk period of cows can effectively alleviate symptoms and inhibit the growth and reproduction of pathogenic bacteria, thus playing a controlling role.
（4） Application in other animals
Timicoxin can also be used for bacterial and fungal infections in sheep and goats. The use of temicoxacin before giving birth to pregnant ewes can reduce mastitis and increase pre weaning weight of lambs. In addition, it can also be used to treat bacterial respiratory diseases in sheep, with a recommended dosage of 10 mg/kg body weight.
Subcutaneous injection of temicoxacin at a dose of 10 mg/kg body weight can significantly reduce clinical symptoms and mortality rate in the treatment of rabbit multi killing pasteurellosis and respiratory diseases.
4、 Adverse reactions
This drug is relatively safe and has no carcinogenic, teratogenic, or embryotoxic effects, but may produce cardiac and renal toxicity. There have been reports of acute cardiotoxicity in cows after intravenous injection of temicoxacin, characterized by ataxia, tachycardia, jugular vein pulsation, excessive breathing, and collapse. However, within 30 minutes, the clinical manifestations were normal, and swelling appeared at the injection site.
There have also been reports of Tilmicosin being used in dogs to induce the aforementioned cardiovascular reactions. There are also reports of intramuscular injection of 5% temicoxacin injection into pigs, using 10 mg/kg body weight, which can cause symptoms such as shortness of breath, vomiting, and convulsions, but does not lead to death; Using intramuscular injection of 15 mg/kg body weight can quickly lead to death in critical cases, while using 20 mg/kg body weight for general cases can cause death within 15 minutes, with a mortality rate of up to 80%. However, the damage and toxic effects of Tilmicosin on the bovine cardiovascular system with adverse reactions mentioned above are mainly due to the use of doses significantly higher than the treatment dose, or the damage to cardiovascular and renal function itself, or the administration method being intravenous injection rather than subcutaneous injection as prescribed; The reason for the occurrence of adverse reactions in pigs mentioned above is due to the use of a dosage form that is not suitable for pigs - injection.
Tilmicosin is mainly excreted through the digestive tract, and with a small dosage and frequency of use, the drug's toxic side effects are generally not obvious, and animals can fully tolerate it.
5、 Medication precautions
（1） Timicoxin injection
Be cautious when using it on animals other than cows, and cows should not be used for intravenous injection. Dairy cows aged 20 months or older should not be used to prevent residues in the milk. Meat calves, calves under 1 month old, or completely fed calves should not be used, and tissue residues in these calves can be maintained until after the discontinuation period; Avoid skin contact as it can cause irritation and allergies. The safety of using pregnant and breeding animals has not yet been determined. The rest period for cattle and calves before rumination is 28 days before slaughter. Research has shown that if milk is administered to cows during lactation, the abandonment period should be at least 82 days or more.
（2） Timicoxin premix
Pig feed must not contain soap clay (i.e. soap clay, used as a premix or supplement). Pigs using Timicosin premix should not be slaughtered until at least 7 days after the last use of the drug.
（3） Timicoxin water dispenser
Prohibited for laying hens. Pigs using Tilmicosin water solution should not be slaughtered until at least 7 days after the last use of the medication. Chicken can only be slaughtered after 10 days.
In addition, attention should be paid to the interaction between temicoxacin and other drugs. The simultaneous use of epinephrine in pigs with temicoxacin can cause an increase in pig mortality, and the simultaneous use of these two drugs should be avoided.