Avermectins Flashcards
Avermectins are antibiotics originally from ____ ____.
Streptomyces avermitilis
What are the 4 generic avermectins?
- Ivermectin
- Doramectin
- Selamectin
- Eprinomectin
What are the 2 generic milbemycins?
- Milbemycin
2. Moxidectin
____ ____ is a diluent used in Ivermectin.
Propylene glycol
What are the 2 constituents of Ivermectin?
- Macrolide
2. Sugar molecule
What are the 4 modes of action of Ivermectin?
- Increases opening of Cl- ions
- Allosteric modulator of ligand-gated ion channels
- Inhibit movement, pharyngeal pumping, and egg laying in nematodes due to increased inhibitory ion-channels
- Inhibit muscle contraction in insects because of GluCl channels present on body muscle
Which of the following is Ivermectin effective against: Nematode adults, nematode larvae, insects, flukes, lice, fleas, filaria, mites.
- Nematode adults
- Nematode larvae
- Filaria
- Insects
- Lice
- Mites
What is the spectrum of Ivermectin in the horse?
- Bots
- Stronglyes
- Pinworms
- Ascarids
- Stomach worms
What is the spectrum of Ivermectin in the pig?
- Major GI worms
- Lungworms
- Kidney worms
What is the spectrum of Ivermectin in the dog?
- Microfilariae
- Whipworms
- Ascarids
Is Ivermectin lipophilic or lipophobic?
Lipophilic
The concentration of Ivermectin is highest in which 3 tissues?
- Liver
- Fat
- Bile
The concentration of Ivermectin is lowest in which tissue?
Brain
____ ____ accounts for 98% of elimination of Ivermectin.
Fecal excretion (via bile)
In which animal can Ivermectin NOT be used?
Lactating diary cows
What is the pre-slaughter withdrawal time of Ivermectin in swine?
5 days (PO
18 days (SQ)
What is the pre-slaughter withdrawal time of Ivermectin in sheep?
11 days (PO)
What is the pre-slaughter withdrawal time of Ivermectin in cattle?
35 days (SQ)
49 days (pour on)
True or False: Ivermectin is teratogenic.
FALSE - Ivermectin is safe in pregnant animals.
Eprinomectin is a treatment for bovine ___ and ___.
Nematodes and ectoparasites
What is the pre-slaughter withdrawal period for Eprinomectin in cattle?
There is NO pre-slaughter w/d period
What is the milk discard time of Eprinomectin in cattle?
There is NO milk discard time
What is Dectomax?
Doramectin
Which is more lipophilic, Ivermectin or Doramectin?
Doramectin
Which has a longer plasma half-life, Ivermectin or Doramectin?
Doramectin
What is the pre-slaughter withdrawal time for Doramectin (SQ/IM)?
35 days
What is the pre-slaughter withdrawal time for Doramectin (pour on)?
45 days
How is Selamectin applied in dogs and cats?
Topically 1x / month
What is the common name of Selamectin?
Revolution
What is Selamectin 1 effective against in the dog?
- Heartworm preventative
- Fleas
- Ear mites
- Ticks
- Sarcoptic mites
What is Selamectin 1 effective against in the cat?
- Heartworm preventative
- Hookworms
- Fleas
- Ascarids
- Fleas
Selamectin 2 is more bio-available in the dog or the cat?
Cat (74% vs. 4%)
What is the plasma half-life of Selamectin 2 in the dog?
11 days
What is the plasma half-life of Selamectin in the cat?
8 days
Which is safer, Selamectin 2 or Ivermectin?
Selamectin 2
Which is longer acting, Ivermectin or Moxidectin?
Moxidectin
Which is more lipid soluble, Ivermectin or Moxidectin?
Moxidectin
What is the pre-slaugter withdrawal time of Moxidectin in cattle?
NONE when administered topically
What is the milk withdrawal time of Moxidectin in cattle?
NONE when administered topically
What is the Moxidectin preparation in the dog called?
Proheart
What is the use of Proheart in the dog?
Oral and SQ against eartworm prevention
What is the Moxidectin preparation in the cat called?
Cydectin
What is the use of Cydectin in the cat?
Injectable and pour on against nematodes and ectoparasites
What is the Moxidectin preparation in the horse?
Quest
What is Milbemycin used to control?
- Heartworm
- Ascarids
- Hookworms
- Whipworms
___% of a Milbemycin dose is absorbed.
10%
Milbemycin can also be used in the control of demodex. What is the treatment plan?
1x / day at 2-3 mg/kg for 1-3 months
True or False: Milbemycin is not to be administered to nursing pups.
FALSE - Milbemycin is not harmful to nursing pups.
True or False: Milbemycin is not to be administered to pregnant bitches because of its harmfulness to fetuses.
FALSE - Milbemycin is not harmful to fetuses.
Review: what is the pre-slaughter withdrawal period of pour-on ivermectin & doramectin in cattle?
7 weeks
Review: what is the pre-slaughter withdrawal period of pour-on eprinomectin & moxidectin?
There is NO withdrawal period
Adverse effects associated with the Avermectins are due to ____ receptor stimulation when these antibiotics get into the brain.
GABA