// Veterinarians must: veterinary medicine matching skills and precautions


Overview: In the treatment of animal diseases, more than one drug is often used in medication. At this time, we need to master a professional veterinary knowledge, that is, veterinary medicine matching skills and precautions. Only a reasonable combination of drugs can make the disease get the effect until the disease is eliminated. Let’s take a look at the veterinary medicine drug matching skills and points of attention:
1. Synergistic effect of joint application of veterinary drugs

The combined application of penicillin + streptomycin has clinical significance. Often synergistic and additive effects can be obtained. Such as: colistin + tiamulin, spectinomycin + lincomycin, neomycin + oxytetracycline; calcimycin + TMP, etc. Because they are bacteriostatic drugs, synergistic effects are generally obtained. Such as: tylosin + sulfonamide + TMP, tiamulin + sulfonamide + TMP, lincomycin + sulfonamide + TMP, oxytetracycline + sulfonamide + TMP, etc. Because fluoroquinolones have both synergistic effects and combined application. Such as: enrofloxacin + amoxicillin, enrofloxacin + colistin, enrofloxacin + lincomycin, enrofloxacin + TMP, etc.
2. Antagonism of combined application of veterinary drugs
Penicillin cannot be combined with florfenicol, tetracyclines, macrolides, and lincomycin.
Because these four can quickly inhibit bacterial protein synthesis and put the bacteria in a stationary state that stops growth and reproduction, the penicillin of the germicide during the reproduction period interferes with the synthesis function of the cell wall and cannot be fully exerted, reducing the efficacy of penicillin. Amoxicillin should not be added to the feed at the same time as the third class of drugs. Although the pharmacological combination of amoxicillin with chlortetracycline or florfenicol may be inadequate, clinical use does not seem to cause adverse reactions.
Although fluoroquinolones have both the first and second class properties, it also highlights its shortcomings, that is, it has partial antagonism or weakening effects with the third and fourth classes.
3. Joint application of veterinary drugs without synergy and weakening
The combination of fungicide and slow-acting bacteriostatic agent during the reproduction period, although there is generally no enhanced or weakened effect, there will be no major impact or antagonism. Due to the poor killing effect on the bacteria whose metabolism is inhibited, it is generally not suitable for joint application. Therefore, when injecting penicillin, there is no need to inject sulfonamides at the same time. The treatment of encephalitis is an exception. When there are obvious indications, sulfadiazine sodium and penicillin are injected intramuscularly (not mixed), which can improve the efficacy of the drug when treating brain bacterial infections.
Fourth, the combined application of veterinary drugs in the same kind of combination increases toxicity or weakens the efficacy
It is not advisable to combine the same drugs. Such as streptomycin, gentamicin, kanamycin, etc. between aminoglycosides should not be used in combination, otherwise it will enhance ear and kidney toxicity. The same class of antibacterial drugs, such as florfenicol, macrolides, lincomycin, and tylosin, have the same mechanism of action. They all act on the 50S subunit of bacterial ribosomes and inhibit the extension of the peptide chain. It hinders the synthesis of bacterial proteins and produces a rapid bacteriostatic effect. They cannot be used in combination, otherwise antagonism may occur. If florfenicol cannot be used in combination with the latter three (macrolides, lincomycin, tylosin), due to the competition site, the latter can replace or prevent florfenicol and 50S subunit Combined to produce an antagonistic effect, resulting in weakened drug efficacy.
V. Joint application of veterinary drugs to increase the efficacy
Florfenicol and doxycycline, tiamulin + chlortetracycline, tylosin + oxytetracycline;
Bacitracin zinc + colistin, sulfonamide + TMP, etc.
6. Combination of combination medicine
1. Tai Wanmycin and florfenicol
Taiwanmycin is the latest generation of macrolide drugs for animals. Compared with other macrolide drugs, its efficacy has been significantly improved, and it has a unique effect on mycoplasma disease, blue ear virus infection and proliferative ileitis. And florfenicol has a good effect on diseases of respiratory and digestive tract infections in livestock and poultry. The above-mentioned combined administration scheme has been widely recognized by farmers in the prevention of respiratory diseases of nursery and fattening pigs, the improvement of resistance of pregnant sows, the prevention and treatment of thorax transmission, and mycoplasma disease (multi-dimensional can be added for adjuvant treatment of diseases, anti-stress Stimulate, to prevent nutritional deficiencies). In addition, tilmicosin or tiamulin also showed a certain effect.
2. Albendazole + Ivermectin
Albendazole is a benzimidazole derivative and a broad-spectrum insect repellent; ivermectin is a derivative of the macrolide antibiotic avermectin, and its insecticidal activity is exceptionally outstanding, and the insecticidal spectrum is broad, In particular, it has a strong killing effect on arthropod insects and nematodes in the body such as gastrointestinal nematodes and lung nematodes, but the avermectin has a poor killing effect on tapeworms and flukes, so the combination of albendazole + ivermectin is used. Administration (golden ratio 50:1) can enhance the extermination of various parasites in vivo and in vitro.
3. Quinocetone + flavomycin
Quinocetone is a quinoxaline dioxide derivative with antibacterial, antidiarrheal, and growth-promoting effects; flavomycin is a phosphorylated polysaccharide antibiotic. Compared with its antibacterial characteristics, it improves feed utilization and promotes livestock and poultry. The role of growth is more concerned. Studies have shown that the addition of quinocetone + flavomycin (5:1) to pig feed in a certain proportion (flavin can be added in poultry feed can be less), the pig daily weight gain (ADG), protein digestibility improvement effect is outstanding, and can be effective Reduce diarrhea rate. Considering the cost of use and the effect of promoting growth, the quinenone + flavomycin feed addition program is highly respected by farmers.
4. Lincomycin + Spectinomycin
Spectinomycin is an aminoglycoside antibiotic and has a good effect on Gram-negative bacteria. Lincomycin is a lincosamide antibiotic and has a strong antibacterial effect on Gram-positive bacteria. The combination of the above two antibiotics, their pharmacodynamic and pharmacokinetic characteristics do not interfere with each other, can expand the antibacterial spectrum, and have a better effect on piglet diarrhea, mycoplasma pneumonia and chicken respiratory diseases.
5. Combination of sulfa synergist and various drugs
Antibacterial synergists (sulfonamide synergists) such as trimethoprim (TMP), the principle of which is to inhibit dihydrofolate reductase so that dihydrofolate cannot be reduced to tetrahydrofolate, thus blocking the metabolic effect of sensitive bacteria. The combination of TMP and sulfonamides at 1:5 can inhibit the synthesis of bacterial folic acid in two stages, thus turning the bacteriostatic effect of sulfonamides alone into bactericidal effect. Not only the sulfonamide pharmaceutical type can achieve better efficacy, and studies have shown that the antibacterial effect of tetracycline, gentamicin and TMP can also be enhanced.
6. Common combination medications
Amoxicillin + clavulanate potassium combined with bonisone dragon is used for the treatment of dairy cow mastitis; tiamulin and chlortetracycline is used for the treatment of chicken mycoplasma septicemia.

Post time: Jun-17-2020