Prophylactic antibiotic levels

In the treatment of infections, decision support programmes provide information on the presence of resistant pathogens, untreated infections, an incorrect dose, route or interval and the need for serum levels and cost effective alternatives to current treatment. Over seven years, 63 000 patients were studied. The proportion of patients receiving antibiotics increased from 31.8 to 53.1%, though overall costs decreased. Treatment with appropriate prophylactic antibiotics before surgery increased from 40 to 99.1%. Antibiotic related adverse drug events decreased by 30%. (ADAPTED FROM EVANS, PESTONIK AND CLASSEN, 1998)... 

Depending on the organ being embolized and the level of embolization, some tissue ischemia or even necrosis may occur. Prophylactic antibiotics maybe indicated to prevent bacterial seeding of the infarcted tissue from developing into an abscess. This may be more of a concern when the embolized artery is in an infected organ such as a renal pseudoaneurysm that occurs after a nephrostomy done for pyonephrosis. Certainly if the patient has known bacteremia, antibiotic coverage should be started prior to the embolization. 

For livestock producers to approach the care we have exercised in in avoiding antibiotic exposure would require a complete ban of all antibiotics and other antibacterial agents. Periodic exposure to prophylactic or therapeutic levels of antibacterials would result in high levels of resistance and, in a production environment, that resistance would be very slow in declining. 

Hemorrhagic disease of the newborn can develop readily because of (1) poor placental transfer of vitamin K, (2) hepatic immaturity leading to inadequate synthesis of coagulation proteins, and (3) the low vitamin K content of early breast milk. Prothrombin levels during this period are only about 25% of the adult levels. Severe diarrhea and antibiotics used to suppress diarrhea readily exacerbate the situation, so prothrombin levels can drop below 5% of the adult level and bleeding can occur. This condition is routinely prevented by the prophylactic administration of 0.5 to 1.0 mg of phylloquinone intramuscularly, or 2.0 mg given orally immediately after birth. 

On the average, 40% of the antibiotics sold in the United States, or more than 1.0 million kilograms, have been used as animal feed additives ( ). According to Aschbacher ( ), the following levels of antibiotic supplementation are recommended for growth promotion Bacitracin at 10-50 g/ton feed, Bambermycins at 1-2 mg/ton, Carbadox at 10-25 mg/ton, Chlorotetracycline at 10-50 mg/ton. Erythromycin at 4-70 g/ton, Lincomycin at 1-11 g/ton, Oxytetracycline at 5-50 g/ton. Penicillin at 2-50 g/ton, Tylosin at 4-100 g/ton and Virginiamycin at 10 g/ton. Higher levels have been recommended for prophylactic purposes. As medical and non-medical use of antibiotics increases, the risks associated with antibiotics in foods and feeds also increase. 

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