Moxidectin + Imidacloprid Topical

By Krista Williams, BSc, DVM, CCRP

What is moxidectin + imidacloprid topical?

Moxidectin is an avermectin antiparasitic that is used to prevent heartworms and treat intestinal parasites (hookworms, roundworms, and whipworms). Imidacloprid treats and prevents fleas. These two drugs are combined as one medication (Advantage Multi®, Imoxi™) for use in cats, dogs, and ferrets (Advantage Multi® only). This combination product is also approved to treat sarcoptic mange and treat circulating heartworm microfilaria (immature heartworms) in dogs. In cats, it may also be used to treat ear mites.

Its use in dogs to treat adult heartworm in combination with doxycycline (Vibramycin®) is "off-label" and is not the recommended first-choice treatment. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their directions may be significantly different from those on the label.

How is moxidectin + imidacloprid given?

Moxidectin + imidacloprid is applied topically to the skin. During the first 30 minutes after application, monitor to ensure that your pet does not lick the product. Follow the label directions for where to apply it to your pet. Do not apply this medication to irritated skin. Do not bathe your pet for at least four days after its application.

Moxidectin + imidacloprid will start working in about 24 hours to kill ticks and intestinal parasites and begins to kill fleas within four hours.

What if I miss giving my pet the scheduled dose?

Give the dose as soon as you remember and start a new monthly dosing schedule. For example, if you forgot to give your pet his/her dose on June 1st and remember on June 18th, give the dose on June 18th and start a new monthly schedule. The next dose your pet will receive would be on July 18th. Do not give your pet two doses at once. Contact your veterinarian if you are concerned about a missed dose.

Are there any potential side effects?

When used as directed in dogs, side effects are uncommon. If the product is ingested, side effects include depression, salivation, dilated pupils, incoordination, panting, and generalized muscle tremors. In dogs that are sensitive to moxidectin, coma and death are possible.

In cats, behavioral changes such as agitation, excessive grooming, hiding, pacing, and spinning may occur. Other side effects may include scratching, application site reactions, rubbing, lethargy, hyperactivity, uncoordinated walking, trembling, excessive salivation, increased drinking, and coughing or gagging. If ingested, increased salivation, tremors, vomiting, and decreased appetite can occur.

Reported adverse reactions in ferrets include itching, scabbing, inflammation, and lethargy.

This long-acting medication is designed to last for at least four weeks. However, negative side effects are usually short-lived if they occur at all. In healthy dogs, even when the medication is accidentally ingested, side effects should not last more than 24 hours.

Are there any risk factors for this medication?

Moxidectin should not be used in pets that are hypersensitive or allergic to it or other avermectin products. This medication should not be used or used with extreme caution in sick, debilitated, or underweight pets, dogs under seven weeks of age, or cats under nine weeks of age.

Some dog breeds (e.g., collies, sheepdogs, and collie- or sheepdog-cross breeds) are more sensitive to moxidectin than others. This is typically due to a specific genetic mutation (MDR1) that makes them less able to tolerate high doses of moxidectin. If used at prescribed doses for heartworm prevention, it is considered safe for MDR1-affected dogs.

The cat formulation of this product contains different drug combinations and should not be used in dogs.

Safety in breeding, pregnant, or nursing animals has not been established, however, there has been no evidence to date of adverse effects on these animals.

Are there any drug interactions I should be aware of?

Specific interactions with moxidectin have not been reported, however, benzodiazepines should be closely monitored when used with moxidectin. There are no currently known drug interactions with imidacloprid.

In dogs with MDR1 genetic mutations, there are several medications that should not be used or should be used with caution with moxidectin. Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

There is no specific monitoring that needs to be done while your pet is taking this medication. Your veterinarian may monitor your pet to be sure that the medication is working.

How do I store moxidectin + imidacloprid topical?

Moxidectin + imidacloprid topical should be stored between 4°C – 25°C (39°F – 77°F).

What should I do in case of an emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

Related Articles