16.11.09 - The trend towards greater use of antibiotics in veterinary medicine continues in Switzerland. According to information from Swissmedic, the Swiss Agency for Therapeutic Products, an increasing amount of modern active substances are also being used, which in human medicine are considered as reserve antibiotics. These substances are used in humans above all when the customary antibiotics are ineffective or when the pathogens have developed resistance to them. In 2008 a total of 73,252 kg of antibiotics were placed on the market for veterinary medicine. Since 2005, the annual quantity of antibiotics sold has increased by as much as 6.8% (+ 4,696 kg).

The increase in the total amount is mainly attributable to the rise in the sales volumes of antibiotics for meat-producing farm animals and within this category the tetracyclines and macrolides. As Swissmedic reports this might be connected to the less frequent underdosing of these preparations. Underdosing is a major factor in the increased occurrence of antibiotic-resistant bacterial strains. So this increase could help to avoid antibiotic resistance. Overall, the antibiotics most used in veterinary medicine are: sulphonamides (2008: 29.5 tonnes) followed by tetracyclines (17.4 tonnes) and beta-lactams (penicillins and cephalosporines, both together 13.9 together).

Around two-thirds of the total amount (49,378 kg) were sold in the form of pharmaceutical premixtures. These are preparations that need to be mixed into animal feed or drinking water before administration and are given mainly to calves and pigs.

Preparations for direct injection into the udders of cows or even sheep and goats amount to 5,674 kg, or approximately 8% of the total quantity sold.  Penicillin accounts for the majority of this amount, with 4,657 kg. In second position are active substances in the aminoglycoside group (827 kg), which are highly effective against the most common bacterial pathogens causing mastitis (udder inflammations).

In both farm animals and pets there is also a trend towards the use of modern, potent active substances. According to Swissmedic's information, several preparations containing new active substances were not authorised until the end of the four-year period under review. This might lead to a further increase in the quantities of modern antibiotics sold in the next few years. Some of these active substances, or at least other members of the same classes of substances are also used in human medicine.

Swissmedic has been collecting data about sales volumes of antibiotics for use in veterinary medicine since 2005. This is only done for antibiotics that are authorised for use as veterinary medicines. This survey is aimed in particular at checking for an association between increases in sales volumes with the development of antibiotic resistance in veterinary medicine. The analysis of the data should furthermore contribute to the identification of trends and formulation of respective recommendations to the address of the veterinary profession.

The full report is available on the homepage of Swissmedic:
http://www.swissmedic.ch/marktueberwachung/00147/00644/index.html?lang=en