Clinical application of gentamicin in veterinary medicine and the advantages of combined medication

Gentamicin has the following characteristics

• 1. It is a bactericidal antibiotic.
• 2. It is a broad-spectrum aminoglycoside.
• 3. There is obvious post-antibiotic effect (PAE) on Gram-negative bacteria and positive cocci, that is, it has a sustained bacteriostatic effect lower than the inhibitory concentration, completely eliminates the drug, or the drug concentration is lower than the minimum inhibitory concentration (MIC). ), the growth of bacteria continued to be inhibited for a certain period of time.
• 4. It is a concentration-dependent antimicrobial drug. Recent studies have shown that the antibacterial activity of gentamicin depends on the effective concentration of cell membrane antibiotics. Under the condition that the daily dose remains unchanged, a single administration can obtain a larger peak plasma concentration of multiple administrations a day, so that the peak concentration of gentamicin can be reduced. The ratio of the concentration to the minimum inhibitory concentration increased, thereby significantly improving the antibacterial activity and clinical efficacy.
• In addition, the post-antibiotic effect (PAE) of gentamicin on pathogenic bacteria is also concentration-dependent. A single daily dose can reduce the incidence of adaptive resistance and ear and nephrotoxicity. Stress reactions caused by injections and injections.
• 5. This product is rarely absorbed when taken orally, and the concentration in the intestinal tract is relatively high. It can be used as a drug for intestinal infection to treat yellow and white diarrhea of piglets and enteritis.
• 6. This product is absorbed rapidly and completely by injection. The peak blood concentration is generated within 0.5-1 hour after intramuscular injection, and the bioavailability can reach 90%. When the dose is increased, the blood concentration can be increased, and the duration can be appropriately extended.
• 7. This product is an alkaline compound, easily soluble in water, relatively stable, and its antibacterial activity is the strongest in an alkaline environment.
• 9. Bacteria are also prone to resistance to this product, but the resistant strains are far less common than streptomycin and kanamycin. The occurrence can be reduced or prevented if the dose is adequate or in combination with other antibiotics and topical administration is avoided. Once it occurs, stop the drug immediately, and the bacteria can regain their sensitivity. There is incomplete cross-resistance among different varieties of aminoglycosides.
• 2. Drug Interactions
• 1. Gentamicin combined with?-lactam antibiotics (such as penicillins or cephalosporins) usually has a synergistic effect on a variety of Gram-negative bacteria, including Pseudomonas aeruginosa. It also has a synergistic effect on Gram-positive bacteria. For example, gentamicin is used in combination with penicillin for Streptococcus, enzyme-resistant semisynthetic penicillin for Staphylococcus aureus, cephalosporin for Pneumococcus, penicillin G or ampicillin for Listeria and Carbenicillin is used in combination with Pseudomonas aeruginosa and so on. This is because?-lactam drugs cause damage to the bacterial cell wall, which increases the uptake of gentamicin by the bacterial membrane, because damage to the cell wall makes the drug more accessible to the cell membrane.
• 2. When used in combination with trimethoprim-sulfanilamide, it also has a synergistic effect on Escherichia coli and Klebsiella pneumoniae.
• 3. In the treatment of severe systemic infection, this product can be used in combination with dexamethasone, florfenicol, etc., and the cure rate is high.
• 4. The antibacterial effect of this product is enhanced in an alkaline environment. Combination with alkaline drugs (such as sodium bicarbonate, aminophylline, etc.) can enhance the antibacterial activity, but the toxicity is also enhanced accordingly. When the pH value exceeds 8.4, the antibacterial effect decreases.
• 5. It is forbidden to mix with vitamin C, so as not to reduce the curative effect.
• 3. Indications
• Gentamicin has a good effect on the treatment of serious infections caused by sensitive bacteria. It is mainly used clinically to control and treat local and systemic infections caused by drug-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus, Pasteurella, Salmonella and other aerobic Gram-negative bacteria. Such as sepsis, genitourinary tract infections, respiratory tract infections (pneumonia, bronchopneumonia), gastrointestinal infections (including peritonitis), mastitis, osteoarthritis and skin and soft tissue infections.
• 4. Usage and Dosage
• The potency of this product is calculated by weight, and 1 gram is equal to 1 million units.
• 1. Oral administration for one day, 10-15mg per kilogram of body weight, divided into 2-3 times a day for 2-3 days.
• 2. Intramuscular injection: one dose, 2-4 mg per kilogram of body weight, 2 times a day, for 2-3 days.
• The above is the dosage recommended by the official "Guide for the Use of Veterinary Drugs".
• The following introduces a prescription for the treatment of piglet diarrhea, which the author has concluded after ten years of repeated tests. The dosage is larger than the official recommended dosage, and the clinical effect is good. Those who are interested may wish to try:
• gentamicin powder 5.0 grams, methoxy 1.0 g of benzylaminopyrim, 20 scopolamine tablets (5 mg/tablet), 13.75 g of oral rehydration salt, 500 ml of cold boiled water, take orally once, 1 ml per kilogram of body weight, 2 times a day, for 2-3 days.
• In order to reduce the stress caused by catching pigs, it can be given once a day, and 2.0 ml per kilogram of body weight can be given.
• If the piglet weighs more than 10kg, it is inconvenient to inject medicine, and gentamicin injection can be intramuscularly injected. One intramuscular injection, 6-8 mg per kg body weight, that is, 0.15-0.2 ml/kg body weight of 4% gentamicin injection, 2 times a day, for 2-3 days. The dose can be doubled if given intramuscularly once a day.
• For severe cases of dehydration, gentamicin injection can also be added to 20-40ml of 5% glucose saline for intraperitoneal injection.
• For severe cases, the dosage can be appropriately increased as appropriate, regardless of oral administration, intramuscular injection or intraperitoneal injection.
• V. Precautions for use
• 1. Although gentamicin can be used in combination with penicillin or cephalosporins, it cannot be diluted with gentamicin injection, and cannot be mixed in the same needle or vial for injection, otherwise it will cause The efficacy of damicin is reduced, and penicillin and gentamicin can be injected or instilled intramuscularly.
• 2. When the newborn piglets do not eat colostrum, it is best not to take gentamicin to prevent piglets from yellow diarrhea. The author once believed in articles published in some newspapers, saying that 60,000 units of gentamicin before piglets eat colostrum can prevent piglets from yellow diarrhea. The author tried this, and the result was that 6 of the 10 piglets died one after another, and the cause of death was the severe ulcer at the bottom of the stomach. Eating a cut grows wisdom. The author suggests that piglets who have not eaten colostrum and have an empty stomach should not take gentamicin to prevent yellow diarrhea, so as to avoid gastric ulcers and cause undue losses.
• 3. This product cannot be used in combination with similar aminoglycosides such as

streptomycin, kanamycin, amikacin, neomycin, etc., to prevent enhanced toxicity.

• 4. This product cannot be injected intravenously and has respiratory depression effect.