Ivermectin (22,23-dihydroavermectin B1a + 22,23-dihydroavermectin B1b) is a broad-spectrum anti-parasitic medication, traditionally used against worms
brand names such as Stromectol® in the United States, Mectizan® in Canada and Ivexterm® in Mexico.

While ivermectin works effectively and relatively safely in the species listed above (with the exception of a few breeds of dogs), it
can be very toxic to
reptiles and especially deadly to chelonians.

The manufacture states that reptiles under no circumstances should be injected with ivermectin

It also has contradictions with animals that have been treated with diazepam within 10 days after being dosed with ivermectin

The dosing that is required in order to be effective in reptiles
can be lethal.  There are other safer options for the treatment of protozoans, ectoparasites
and endoparasites.  Personally - I wouldn't chance it.

Melissa Kaplan's
site has a page discussing mites and ivermectin and is a good read (you will find it a little more than half way down the page).  
I encourage you to read more and do some research on this subject to ensure that nothing dangerous happens.
Written by: Robin Moniz 2008
Dr. Fredrick L. Frye D.V.M., M.S Biomedical and Surgical Aspects of Captive Reptile Husbandry
Wikipedia.org Encylopedia
Melissa Kaplan anapsid.org