Tilmicosin is a

macrolide antibiotic The Macrolides are a class of natural products that consist of a large macrocycle, macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-memb ...

. It is distributed under the brand name Micotil. It is used in veterinary medicine for the treatment of bovine respiratory disease and

enzootic pneumonia Pasteurellosis is an infection with a species of the bacterial genus ''Pasteurella'', which is found in humans and other animals. ''Pasteurella multocida'' ( subspecies ''P. m. septica'' and ''P. m. multocida'') is carried in the mouth and respi ...

caused by ''Mannheimia (Pasteurella) haemolytica'' in sheep. In humans, Tilmicosin causes fatal cardiotoxic effects at amounts greater than 1 milliliter when injected, something most commonly seen in veterinary personnel and farmers. Tilmicosin, like most macrolides, is a

Calcium channel blocker Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...

. However, because Micotil is formulated for animals like cows, it has exceptionally more epotent Ca channel blocking effects in humans with a dose of .5 mL causing significant poisoning and a dose of 5-6 ml being lethal.

References

{{Reflist Macrolide antibiotics Veterinary drugs