What is Ivermectin?

Article Details
  • Written By: Marjorie McAtee
  • Edited By: W. Everett
  • Last Modified Date: 29 September 2019
  • Copyright Protected:
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog
The longest lightning bolt ever recorded stretched 199.5 miles (321 km) -- nearly the entire length of Oklahoma.  more...

October 18 ,  1867 :  The US bought Alaska from Russia.  more...

Ivermectin is a broad-spectrum antiparasitic medication often used to treat parasitic worm infestations in animals and humans. In humans, ivermectin is most often used to treat threadworm, or strongyloidiasis, infestation and river blindness, or onchocerciasis. It's also sometimes prescribed to treat other parasitic infestations, including scabies, lice, and roundworm. In animals, especially dogs and cats, ivermectin is often used to treat and prevent heartworm, and to treat ear mites and some types of mange. Like most other prescription drugs, ivermectin can have drug interactions, contraindications, and side effects.

Strongyloidiasis is a parasitic infestation of threadworms. Threadworms usually access the body by burrowing through the skin, making their way through the muscle tissue to the bronchial tubes, and then entering the gastrointestinal tract through the esophagus. Rarely, threadworm infestations can occur in other parts of the body, including the uterus, lungs, and liver.

These infestations can be very difficult to treat, especially in children, because the risks of reinfection are often high. Usually, one dose of ivermectin is taken to treat threadworm. If additional doses are needed, they are generally administered three, six, or 12 months after the initial dose.


River blindness, also known as onchocerciasis, generally spreads through the bites of blackflies. It occurs mostly in tropical African countries, though this infestation has been known to occur in the tropical nations of Central and South America as well. River blindness can damage the skin so badly as to disfigure its victims, and is believed to be the second most common cause of infectious blindness in the world. Doctors generally monitor their patients' progress during treatment by examining a series of stool samples. The results of these tests can tell the doctor how well treatment is working and how long it needs to continue.

Heartworm in dogs can be treated and prevented by administering ivermectin. Sarcoptic, demodectic, and notoedric mange can also be treated. Ivermectin may be used to treat ear mites in both cats and dogs. Side effects in animals are generally rare, and, when they do occur, are usually mild.

Ivermectin dosages for humans and animals are usually determined based on body weight. Side effects of ivermectin usage in humans can include diarrhea, vomiting, weakness, dizziness, and uncontrollable shaking. Ivermectin can interact with certain drugs, including those used to treat mental illness, anxiety, and muscle spasms. Patients are generally advised to discuss their use of prescription and non-prescription drugs, medical history, and use of alcohol before taking ivermectin.


You might also Like


Discuss this Article

Post 6

@Azuza - That sounds sensible. I've never had lice but when I was younger my sister got them. I remember my mom spent hours combing the eggs out of her hair and shampooing. It was time consuming, but the lice eventually went away.

I think it's interesting this medicine can be used for both people and animals. I always thought most medicine would be for people or animals, but not both.

Post 5

Ivermectin side effects for humans sound pretty unpleasant. However, if I ever develop a parasitic infection I think I will just take my chances. Parasitic infection sounds way worse than the side effects from the medication.

Alhtough, if I ever have children I doubt I would use this to treat lice. Lice are gross, but definitely not as harmful as other parasites. I think I would try the shampoo and combing first before resorting to ivermectin.

Post 4

For those of you looking for a cheaper alternative to ivermectin for dogs, I have a suggestion. My vet actually recommended this, so I know it is safe.

I have five dogs, and ivermectin tablets are expensive for even one dog. I asked my vet if there was anything else I could give them, and she sold me a bottle of ivermectin for cows. It came with a syringe marked with measurements, and she said that as long as I administered the proper dosage for each dog’s body weight, it would be totally safe and effective.

One bottle was only $30, and it has lasted over a year. Buying the ivermectin pills formulated for dogs would have cost me hundreds by now.

Post 3

@Oceana - There is another option. My sister is a vet’s assistant, and her vet told her about a second type of treatment. It doesn’t get rid of the worms immediately, but it does phase them out, and you don’t have to worry about your dog dying from a clot.

I came to her for advice when my vet found a light positive for heartworms in my dog. Like you, I was terrified of the danger. Also, my dog was young and had an extremely high energy level. I knew that even in confinement, she might wiggle around enough to cause a clot.

She told me that all I had to do was keep my dog on her monthly dose of ivermectin. It would keep the heartworms from being able to reproduce further, and the adult ones would die off in two years. She had tried this with her dog, and it worked.

Post 2

Keeping a strict routine of ivermectin administration is so important to your dog’s health. I was just two weeks late giving my dog her dosage, and she got heartworms during that time.

I had taken her to the vet last week for an injured paw pad, but while we were there, the vet tested her for heartworms. She showed a light positive.

The vet recommended a treatment that is similar to chemotherapy. Basically, she would administer injections to poison the heartworms, but this poison would also make my dog sick. I would have to keep her confined for weeks, because if she jumped around too much, a wad of heartworms could break free and cause a clot that could kill her.

I am currently saving up the money for the expensive treatment. It sounds so dangerous, and I know she will be so miserable in a cage for weeks. Does anyone know of another option for treating the heartworms?

Post 1

I use ivermectin once a month for heartworm prevention in my dog. It comes in pill form. The pill is brown, round, and chewable. It must taste good, because my dog takes it from my hand voluntarily and begs for more. I have heard of some owners having to wrap their pills in cheese to coerce the dog to eat them, but mine isn’t picky.

Ivermectin pills provide a very easy way to protect my dog’s health. Heartworms come from mosquito bites, and the area I live in is infested during the summer, so my dog gets bitten countless times. Ivermectin renders these bites harmless, at least as far as heartworm development is concerned.

Post your comments

Post Anonymously


forgot password?