Aivlosin

Aivlosin is an antibiotic.

In pigs, it is used to treat or for metaphylaxis of a number of infectious diseases that are caused by bacteria that affect the lungs (i.e. swine enzootic pneumonia) or the intestinal tract (swine dysentery or porcine proliferative enteropathy). Metaphylaxis refers to the simultaneous treatment of both diseased animals and clinically healthy animals in close contact with them. Aivlosin improves the health and weight of the animals, but may not eliminate completely the bacteria that caused lung infection.

In chickens and pheasants, it is used for treatment or metaphylaxis of lung infections caused by a bacterium Mycoplasma gallisepticum. In turkeys, it is used to treat lung infections caused by a bacterium, Ornithobacterium rhinotracheale, which can cause illness when it is complicated by other viral and bacterial infections.

Aivlosin is available as a premix for medicated feeding stuff and as an oral powder for pigs, and as granules for use in drinking water for pigs, chickens, turkeys and pheasants. It can only be obtained with a prescription.

The premix is mixed into pig feed by an authorised feed mill and the resulting “medicated feeding stuff” is then distributed to the farmer to treat a large number of pigs. The oral powder is mixed into pig feed by the pig owner and is used to treat individual pigs. The granules are added to the drinking water system, either directly or after dilution into a stock solution.

Since the composition of the pig feed might affect the effectiveness of Aivlosin, it should only be used in dry feed. The oral powder cannot properly be mixed into pellets and should therefore not be used in pelleted pig feed.

The active substance of Aivlosin is tylvalosin (previous name: acetylisovaleryltylosin), an antibiotic of the macrolide group. It works by blocking the bacteria's ribosomes, the parts of the cell where proteins are produced, and inhibits the growth of bacteria.

The antimicrobial effectiveness of tylvalosin against bacteria causing diseases was investigated in the laboratory. The main clinical studies on the effectiveness of Aivlosin were carried out on farms in a number of countries in Europe as well as outside the EU.

The studies in pigs were carried out either in pigs already affected by the disease or in pigs who had been in contact with diseased animals on the same farm and were, therefore, likely to develop the disease as well. The studies showed that pigs treated with Aivlosin showed less severe signs of disease than untreated animals. The treatment success with Aivlosin was similar to the effectiveness of other medicines of the same class authorised for such diseases in pigs.

A further set of studies investigated Aivlosin in diseased chickens and pheasants as well as in very young chicks that hatched from eggs, which came from flocks where the disease was present. Chickens and pheasants treated with Aivlosin showed less severe signs of disease than untreated animals. The effectiveness of Aivlosin was similar to that of other medicines of the same class already authorised for this disease in chickens. The treatment did not completely eliminate all bacteria in the respiratory system and some birds still showed the disease; however, the number of affected animals was significantly smaller than in an untreated group of birds.

In turkeys only laboratory studies were performed. These included a dose confirmation study in turkey poults (young turkeys) artificially infected with a lung virus (avian pneumovirus) and Ornithobacterium rhinotracheale, to simulate a complicated infection. Poults either received treatment with Aivlosin or no treatment three days later. The main measure of effectiveness was damage to lungs and air sacs, which was less for the Aivlosin-treated turkeys than for the untreated group.

For the full list of restrictions, see the package leaflet.

People who have had reactions when handling Aivlosin or similar products should avoid any contact with Aivlosin.

When mixing Aivlosin into feed or drinking water or handling the medicated feed or water, direct contact with eyes, skin and mouth should be avoided and protective equipment should be worn, e.g. overalls, gloves and face masks (respirator). Skin that has been in contact with Aivlosin or medicated feed or drinking water should be washed.

Aivlosin should not be used in people. However, if Aivlosin is accidentally consumed by a person, immediate medical advice should be sought and the package leaflet or label shown to the doctor.

The withdrawal period is the time required after administration of the medicine and before the animal can be slaughtered and the meat used for human consumption. It is also the time required after administration of a medicine before eggs may be used for human consumption.

The withdrawal period for meat from pigs treated with Aivlosin given in the feed is two days and one day with Aivlosin given via drinking water. The withdrawal period for meat from chickens, turkeys and pheasants treated with Aivlosin given via drinking water is two days.

The withdrawal period for eggs from chickens treated with Aivlosin is zero days. The medicine is not authorised for use in turkeys producing eggs for human consumption. It should not, therefore, be used in laying turkeys nor for three weeks before turkeys are likely to start laying eggs for human consumption.

The Agency’s Committee for Medicinal Products for Veterinary Use (CVMP) concluded that Aivlosin’s benefits are greater that its risks and recommended that it be approved for use in the EU.

The European Commission granted a marketing authorisation valid throughout the EU for Aivlosin on 9 September 2004.

For more information about treatment with Aivlosin animal owners or keepers should read the package leaflet or contact their veterinarian or pharmacist.