Thursday, March 11, 2010
If your cat has hyperthyroidism and you give it methimazole (trade name Tapazole or Felimazole) be sure to wear gloves when handling and administering the pills.
Though I've had many clients' cats take the transdermal methimazole, which is a gel that is applied inside the cat's ear, and I know (and was instructed) to wear gloves when administering this because it is absorbed through the skin, I was not aware that I should be wearing gloves when handling, breaking or administering this drug in pill form.
Veterinarians for decades have prescribed methimazole for cats, off-label; the drug is licensed for human use. Naturally, the safe handling instructions are intended for the individual who is the patient. But since they have come out with Felimazole, which is made specifically for cats the handling instructions are different because the recipient is not the one administering it. For example, the label for Felimazole has a section headed “Human Warnings” that reads, in part: “Wash hands with soap and water after administration to avoid exposure to drug. Do not break or crush tablets. Wear protective gloves to prevent direct contact with litter, feces, urine or vomit of treated cats, and broken or moistened tablets. Wash hands after contact with the litter of treated cats.”
According to Laura Alvey, a spokeswoman for the FDA's Center for Veterinary Medicine: "Since cats don’t self-medicate, they rely on their owners to administer the medication and because cats often don’t cooperate with administration of oral medication, there is potential for the pill to become wet/mushy/coating lost with re-administration, which could expose the owners to the drug unknowingly, if the coating is melted away. If they don’t wash their hands after administering the medication, repeated exposure could pose a risk to humans".
Alvey added that inherent risks exist for people who handle their own methimazole medication, as well, “but those instructions are left to the physicians to communicate,” she said. “We were concerned with people unknowingly exposing themselves to the drugs in ways they wouldn’t normally be aware of.”
The main reason for wearing gloves and washing hands is to avoid accidentally ingesting any drug residue on the hands, Alvey said, but she noted that methimazole presumably can be absorbed through the skin as well, since the medication often is compounded into a transdermal product.
Source: Veterinary Information Network, Inc., 2/1/10