Sows should not abuse sulfa drugs to prevent and control diseases

Sulfonamides are a class of chemically synthesized antibacterial drugs containing ammonia benzenesulfonamide. It is occasionally discovered that the azo dyes have been multiplied (193g, Domagk) has a good inhibitory effect on streptococcus and staphylococci; 1933 In the first report, the first case of using Bailang multi-raise to cure staphylococcal sepsis was first reported and started to be used in clinical practice. In 1948 No.hey established the necessity of antibacterial activity against sulfonamides. After the chemical structure established the relationship between chemical structure and antibacterial activity, the whole world began research on the chemical structure and antibacterial activity of a large number of sulfonamides, forming a series of short-acting, medium-efficiency and clinically useful meanings. Long-acting sulfonamide.

Sulfonamides are widely used in the prevention and control of various animal diseases because of their broad-spectrum antibacterial properties, convenient use, rapid absorption, strong penetrability, stable nature and low cost. Its indications mainly include: prevention and treatment for mixed infection, secondary infection and various sepsis caused by toxoplasma, coccidia, streptococcus, Haemophilus hominis, B. septicum, Escherichia coli and Salmonella; It has special ability to penetrate the blood-brain barrier, blood-thorax barrier, plasma barrier and blood-barrier barrier, and is commonly used in the treatment of meningitis, arthritis, pleurisy, peritonitis, uterine vaginitis and sepsis. At present, the most commonly used sulfa drugs are: sulfa hexamethoxypyrimidine (long-acting sulfonamide, mainly used for toxoplasma, mixed sensation and sepsis, etc., is currently the most effective and long-acting sulfonamide in clinical practice, Its acetylation rate is also low, it is difficult to form sulfonamide crystals in the kidney and damage the kidney), sulfamethazine (short-acting sulfonamide for mild infection of sensitive bacteria), sodium sulfadiazine (medium-effect sulfonamide, tissue penetration) The most powerful drugs, mainly for meningitis, arthritis, etc.), sulfachloropyridazine sodium (mainly used for coccidia, etc.).

In recent years, due to multiple sows and sows in sows, multiple mixed infectious sepsis, mastitis, arthritis, meningitis, pleuropneumonia, and hemorrhagic protozoa such as toxoplasma and coccidia, sulfonamides Drugs have been widely used in sows, alleviating some clinical problems. However, we have neglected the toxic side effects of sulfa drugs, especially the adverse effects on sows and fetuses, and a series of problems have emerged. The situation is reported as follows:

1. Fully understand the misuse of the use of sulfonamides

Sulfonamides are chronic bacteriostatic agents. There are many points that need special attention in clinical use: (1) sulfa drugs cannot be selected to prevent and control diseases; (2) correct use of sulfonamides: significant clinical application For the first time, the amount of blasting must be used, that is, 2-4 times of the normal dose, and then the normal dose is used, and the symptoms are obviously relieved and then halved. Because the bacteriostatic activity of sulfonamides is p-aminobenzenesulfonamide, which is very similar to p-aminobenzoic acid (PABA), competitively competes with PABA for binding sites for dihydrofolate synthetase, due to PABA and dihydrofolate synthesis. The affinity of the enzyme is much larger (about 5,000 to 15,000 times). Therefore, if long-term low-dose sulfonamides only increase the side effects and drug resistance, it will not achieve the purpose of clinical application; (3) the best Can be used in combination with trimethoprim (TMP) to double block bacterial folate synthesis, so as to truly increase the bacteriostatic activity of sulfonamides; (4) alkalinize urine with the same amount of sodium bicarbonate for 2 days when using sulfonamide To avoid the formation of crystals and cause acute damage to the kidneys.

2, fully understand the sulfa drug use environment, avoid medication errors and increase drug resistance

Sulfonamide bacteriostatic activity is directly related to the environment of the drug: bacteria that can directly use folic acid (such as mycoplasma, rickettsia, and even promote the growth of rickettsia), a large number of abscesses or necrotic tissue (containing a large number of PABA, and streptococcal disease is the most likely to form abscesses), for fermentation products or sites (such as fermenting pigs, PABA in fermented foods), procaine for breast or joints (in vivo decomposition to produce large amounts of PABA) Etc., sulfonamides should be avoided as much as possible. Otherwise, the antibacterial activity of sulfa drugs is greatly reduced or even ineffective due to the presence of PABA.