What are the considerations for the use of antimicrobials?

Antibiotics are often used to prevent and treat bacterial diseases in livestock and poultry, but some problems should be paid attention to during use.

1) Correct selection of drugs: in the prevention and treatment of a certain disease of ducks, there are often several drugs available, but generally should be based on the principle of the best prevention and control effect, small adverse reactions, and low price and easy to obtain.

2) Do not abuse antimicrobials as insurance drugs, the abuse of antimicrobials is not only not beneficial, but also harmful. Long-term use of a certain antibiotic will make some bacteria resistant and make the antibiotic ineffective, and will also destroy the balance between the normal flora in the animal, the sensitive bacteria will be inhibited, and the drug-resistant strains will multiply in large numbers, and it will be difficult to cause double infection, such as long-term diarrhea. Therefore, antibiotics should be used sparingly or not at all; You can use one and never many; The dosage should be sufficient and the course of treatment should be sufficient; In general, it is not suitable to use antibiotics as feed additives for a long time.

3) When combining drugs, the purpose should be clear and reasonable, otherwise the effect is not good, and it is generally believed that the combination of two antibiotics can improve the bactericidal power, expand the scope of sterilization, and reduce or delay the emergence of drug resistance. However, if the combination of drugs is improper, not only can not increase the bactericidal power, but on the contrary, it will antagonize each other, or increase ***. If penicillin is combined with tetracyclines, the bactericidal power of penicillin will be reduced.

When applying antimicrobial drugs, it is necessary to choose the best regimen according to the type of microorganisms infected by the patient, the patient's physical state, and the antibacterial effect, antimicrobial spectrum, selectivity and impact on the body of the drug. If any aspect is ignored and the unreasonable application of antimicrobial drugs will not only cause adverse reactions that affect the health of patients, but also produce unique resistance to antimicrobial drugs, which is even more harmful. It will not only affect the effectiveness of the user, but also cause a serious social impact, once the drug-resistant strain is produced, it will become very difficult to infect it.

Factors to consider when choosing which antimicrobial** to use:

1. Identify pathogenic bacteria as soon as possible.

For patients with confirmed or suspected surgical infection, the pathogenic bacteria should be identified as soon as possible, drug susceptibility tests should be conducted, and antimicrobial drugs should be selected in a targeted manner. Before the pathogenic bacteria and drug susceptibility results are known, critically ill patients should select the most likely pathogenic bacteria on the basis of clinical diagnosis and the local bacterial resistance**; After the results of the pathogenic bacteria and panicle susceptibility test are obtained, the drug regimen should be adjusted in combination with the previous ** effect.

2. Choose the best antimicrobial drugs.

All kinds of antimicrobial drugs have specific antibacterial spectrum and indications, and different pathogenic bacteria have different sensitivity to drugs, so it is necessary to choose drugs with high efficacy, low toxicity, convenient application, and low price and easy to obtain according to clinical diagnosis, bacteriological examination, drug effect and pharmacokinetic characteristics (absorption, distribution, metabolism and excretion process).

3. Formulate a reasonable medication regimen: The following factors should be considered when formulating a medication regimen:

1. Route of administration: For those whose infection is limited or mild and can accept oral administration, antibacterial drugs with complete oral absorption should be selected. Patients with severe infection should be given intravenous drugs to ensure the efficacy of the drug.

2. Dosage: Administered according to the dosage range of various antimicrobial drugs. The bactericidal effect of dose-dependent antimicrobial drugs such as aminoglycosides and quinolones is related to the drug concentration, and the dosage should be biased towards the high limit.

B. Lactams, macrolides and other time-dependent antibacterial drugs, as long as the blood concentration exceeds the minimum inhibitory concentration (MIC), it can exert a bactericidal effect, so the dosage should be biased to the low limit, and the blood concentration can be maintained to be greater than the MC level.

Common reasons for antimicrobial failure:

1. Antimicrobial resistance and the type of bacteria infected.

The bacteria develop resistance to the antimicrobial drugs used, leading to drug failure. Some bacterial species are not susceptible to certain antimicrobial drugs, such as Pseudomonas spp., Acinetobacter spp., etc., which can easily cause drug failure.

2. The site of infection and the physiological and pathological conditions of the patient.

Some sites of infection, such as alveolar lavage fluid, cerebrospinal fluid, etc., are not easy for drugs to reach the site of infection, resulting in drug failure. The patient's age, liver and kidney function and other conditions will affect the selection and dosage of antimicrobial drugs.

The application of antimicrobial drugs should follow the principles of safety, effectiveness and economy.

Data Extension:

The selection of antimicrobial agents should first clarify the clinical indications of the patient, identify the pathogen causing the infection, and select antimicrobial drugs with high efficacy and low toxicity**. The purpose of antimicrobial combination is to improve the efficacy and reduce the dose of individual drugs, thereby reducing adverse reactions and delaying the emergence of drug resistance.

For cases of mixed infection or bacteriological diagnosis, the combination of drugs can expand the antibacterial range, but improper use can also produce serious adverse consequences, such as an increase in the incidence of adverse reactions and more drug-resistant strains, so it is not appropriate to blindly combine drugs.

When choosing antimicrobial drugs, the clinical indications for patients should be clarified first. Identify the causative agent causing the infection (preferably with bacteriological diagnosis and in vitro susceptibility testing) and select antimicrobial agents with high efficacy and low toxicity**.

If unidentified, a combination of drugs or broad-spectrum antimicrobials is often used. In addition, the antimicrobial activity, pharmacokinetic characteristics, adverse reactions and economy of antimicrobial drugs should also be considered.

In the application of antimicrobial drugs, the patient's condition should be considered, such as age, weight, genetics, body resistance, lactation, pregnancy, liver, kidney function, etc., and the use of teratogenic drugs and drugs that affect infant growth should be strictly controlled for pregnant women and lactating women, such as tetracyclines, chloramphenicol, erythromycin succinate, etoerythromycin, aminoglycosides, fluoroquinolones, sulfonamides, metronidazole, ticarcillin, etc. For infants and the elderly, it is necessary to consider that the liver and kidney function are not yet mature or have declined in the large osmotic chain, which often causes the blood concentration to be too high, the half-life is prolonged, and the <> is

Drugs that are harmful to the liver and kidneys should be avoided. The choice of dose and course of treatment should be appropriate, the dose is too small to achieve the best effect, and it is easy to cause bacterial resistance; Excessive doses can cause waste and potentially cause serious adverse effects.

The prophylactic use of antimicrobial drugs should also be strictly indicated to prevent drug abuse. Prophylactic use is limited to a few cases, such as burns, sepsis prevention, neonatal ophthalmia, and epidemic disease epidemic prevention.

Antimicrobial drugs are mainly used for diseases caused by bacterial infections, and are not effective against various viral infections, such as influenza, and it is not necessary to use conventional antimicrobial drugs.

Answer]: b Antimicrobial drugs should be used cautiously, not abused, drug susceptibility test should be done before use, for specific susceptible bacteria, and antibiotics should not be used blindly and prematurely to avoid bacterial resistance.