Proposal for Tulathromycin

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Veterinary Drugs Directorate
Holland Cross Complex
Ground floor, Suite 14
11 Holland Avenue
Address Locator: 3000A
Ottawa, ON K1A OK9

File No: 9457-5-26

April 5, 2007

Dear Stakeholder:

The Veterinary Drugs Directorate (VDD) of Health Products and Food Branch, Health Canada, is considering a regulatory amendment which may be of interest to your organization. Since you are the designated contact for your organization, I would appreciate your collaboration in distributing this information to the attention of all interested parties to solicit their comments.

More specifically, the Veterinary Drugs Directorate is proposing to establish Maximum Residue Limits (MRLs) in Table III to Division 15, Part B of the Food and Drug Regulations for Tulathromycin in edible tissues of food-producing animals as indicated in the following table:

Column I Common Name (or brand name of drug)	Column II Name Of Substance For Drug Analysis Purposes	Column III MRL p.p.m.	Column IV Foods
Tulathromycin	(2R, 3S, 4R, 5R, 8R, 10R, 11R, 12S, 13S, 14R)-2-ethyl-3,4,10,13-tetrahydroxy-3, 5, 8, 10, 12, 14-hexamethyl-11-[[3, 4, 6-trideoxy-3- (dimethylamino)-β-D-xylo-hexopyranosy1]oxy]-1-oxa-6-azacyclopenta-decan-15-one expressed as tulathromycin equivalents	1.0	Muscle of cattle
		2.0	Liver of cattle
		4.0	Kidney of cattle
		1.5	Muscle of swine
		4.0	Liver of swine
		5.0	Kidney of swine

Tulathromycin is a semi-synthetic macrolide antibiotic of the sub-class triamilide. Its mode of action is primarily bacteriostatic, but, may be bactericidal against some pathogens. It acts by binding to a bacterial ribosomal sub-unit thereby inhibiting protein synthesis. Tulathromycin is used for treatment of bacterial respiratory diseases (BRD and SRD) in cattle and swine. The dose is a single-dose of 2.5 mg/kg bw by subcutaneous injection to cattle and intramuscularly to swine. This product is not to be used in lactating dairy cattle. Tulathromycin is approved in Canada under the name of Draxxin Injectable Solution.

The result of our Health Risk Assessment shows residues at the above-noted concentrations will not pose any undue health risk for consumers. The proposed MRLs will be published in the Canada Gazette, Part I, after consideration of comments from Stakeholders.

I would appreciate receiving your comments on this proposal by July 3, 2007. Comments should be sent to the attention of Julie Cameron, Public Involvement Administrator, at the above noted address.

Thank you for your cooperation in this matter.

Yours sincerely,

Siddika Mithani, Ph.D
Director General