What is moxidectin?
Moxidectin topical (brand names: Advantage Multi®, Advocate®) is a topical antiparasitic that is used to prevent heartworms and treat intestinal parasites (hookworms, roundworms, and whipworms). It is combined with imidacloprid to also treat fleas.
It is also approved for treating sarcoptic mange and for treating 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 is “off label” or “extra label”. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How is moxidectin given?
- Moxidectin is applied topically to the skin.
- Ensure the medication is placed on the skin and not on the hair.
- During the first 30 minutes after application, monitor to ensure that your pet does not lick the product.
- Do not apply this medication to irritated skin.
- Do not bathe your pet for at least 4 days after its application.
Moxidectin will start working in about 24 hours to kill ticks and intestinal parasites. Imidacloprid, the medication paired with topical moxidectin, begins to kill fleas within four hours.
What if I miss giving my pet the medication or my shipment is late?
Give the dose as soon as you remember and start a new monthly dosing schedule. For example, if you forgot to give your pet their dose on June 1, and you remember on June 18, give the dose on June 18 and start a new monthly schedule. The next dose your pet will receive would be on July 18. 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?
In dogs, side effects are uncommon when the medication is used as directed. In dogs that are sensitive to moxidectin, coma and death are possible.
If the product is eaten, possible side effects in dogs include:
- depression
- salivation
- dilated pupils
- incoordination
- panting
- generalized muscle tremors
In cats, behavioral changes may occur, such as agitation, excessive grooming, hiding, pacing, and spinning. Other side effects may include:
- scratching
- application site reactions
- rubbing
- lethargy
- hyperactivity
- uncoordinated walking
- trembling
- excessive salivation
- increased drinking
- coughing or gagging
If the product is eaten, possible side effects in cats include:
- increased salivation
- tremors
- vomiting
- decreased appetite
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 dogs, even when the medication is accidentally ingested, side effects should not last more than 24 hours in a healthy animal.
Are there any risk factors for this medication?
Moxidectin topical should NOT BE USED in:
- pets that are hypersensitive or allergic to it
- cats who are sick, debilitated, or underweight
Moxidectin topical should be USED WITH CAUTION in:
- animals with low body fat (sick or very young) as they are more prone to side effects
Safety in breeding, pregnant, or nursing animals has not been established, however, there has been no evidence to date of adverse effects in these animals.
Some breeds of dog (e.g., collies, sheepdogs, and collie-cross or sheepdog-crosses) are more sensitive to moxidectin than others. This is typically due to a 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.
Are there any drug interactions I should be aware of?
Interactions with moxidectin have not been reported; however, benzodiazepines should be closely monitored when used with moxidectin.
In dogs with MDR1 genetic mutations, the following medications should not be used or should be used with caution with moxidectin:
- amiodarone
- cyclosporine
- diltiazem
- erythromycin
- itraconazole
- ketoconazole
- spinosad
- spironolactone
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.
Is any monitoring needed with this medication?
No specific monitoring is needed 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 topical?
Moxidectin topical should be stored between 4°C and 25°C (39°F–77°F).
What should I do in case of 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.
