Drugs that are approved by FDA specifically for cats are important for feline health. This article contains information about three FDA-approved drugs for cats. Mirataz (mirtazapine transdermal ointment) to manage undesired weight loss; Elura (capromorelin oral solution) to manage undesired weight loss specifically in cats with long-term kidney disease; and Semintra (telmisartan oral solution) to control high blood pressure. All three drugs are available only with a veterinarian’s prescription.
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Mirataz and Elura for Managing Undesired Weight Loss in Cats
Weight loss is often the first sign of illness in cats. For example, cats with kidney or dental disease or those with stomach and intestinal problems often lose weight. Although treatment is aimed at managing or, hopefully, curing the underlying disease, medication may be needed to try to stop or slow down the undesired weight loss.
Mirataz is a topical ointment that you apply to the inside (non-hairy) part of your cat’s ear. The drug is absorbed transdermally, meaning through the skin. The active ingredient in Mirataz is mirtazapine. Scientists don’t know exactly how it works to induce weight gain, but it’s likely due to multiple factors.
You apply a 1.5-inch ribbon of Mirataz ointment topically once daily for 14 days, switching between the left and right ears. Your veterinarian or trained veterinary staff will show you how to apply it. You can also refer to the drug’s carton for pictures and a measuring ruler. On the first day, apply the ointment to the inside of your cat’s left ear. On the second day, apply it to inside of his right ear, and then keep alternating ears for the 2 weeks of treatment.
When applying Mirataz, wear disposable gloves so you don’t accidentally get some of the ointment on your skin. Throw out the gloves after each use and then wash your hands with soap and water. Also, separate your cat from people or other animals in your household for 2 hours after each dose. This prevents household members, including other pets, from being accidentally exposed to the ointment and allows time for the drug to be absorbed by your cat.
You may see skin reactions on your cat’s ears in the area where you apply the ointment (redness is the most frequent reaction). He may vocalize more than normal and become hyperactive. Vomiting is also a side effect in some cats receiving Mirataz, likely due to them grooming the ointment off their ears and ingesting the drug.
Veterinarians should use caution when prescribing Mirataz for cats with liver or kidney disease. The drug may cause increased liver values. Cats with kidney disease may be slower at clearing Mirataz from their system, resulting in higher drug levels in the body.
After you stop giving Mirataz, your cat may have a decreased appetite. If he stops eating most of his food for several days or doesn’t eat anything for more than 2 days, contact your veterinarian.
Compounded Products Made from Bulk Mirtazapine are Unapproved
Many drug compounding pharmacies offer transdermal mirtazapine products for cats. These products are legal as long as FDA-approved Mirataz is the source of the mirtazapine in the compounded product. (Drug compounding is the process of combining, mixing, or altering ingredients to create a medication tailored to the needs of an individual animal or a small group of animals.)
However, some drug compounding pharmacies make transdermal mirtazapine products for cats that are compounded from bulk mirtazapine. These products aren’t legal and FDA considers them to be unapproved animal drugs. They haven’t been reviewed by FDA to make sure they are safe, effective, properly manufactured, and adequately labeled and packaged.
Mirtazapine Products Approved for People
Several mirtazapine products are FDA-approved for people, which veterinarians can legally use in cats in an extra-label manner. However, the human-approved mirtazapine products haven't been proven to be safe and effective in cats. Also, the labeling includes information on how to use the drug in people, not in cats. (Extra-label means using an approved human or animal drug in a way that isn’t listed on the drug’s labeling. FDA hasn’t reviewed the safety and effectiveness of the drug for that particular use. Extra-label use is sometimes called "off-label" because the use isn't on the label.)
Another concern with using human-approved mirtazapine products in cats is the difference in dose. The smallest strength for people is 15 mg while the typical dose for cats is 2 mg. It’s very difficult to cut a 15-mg tablet for people into the appropriate dose for a cat.
With the approval of Mirataz, veterinarians can now prescribe an approved mirtazapine product with known safety and effectiveness in cats rather than rely on unapproved compounded products or products intended for people.
Similar to Mirataz, Elura is approved to manage undesired weight loss in cats; however, the drug is specifically for cats with long-term kidney disease, called chronic kidney disease or CKD. One of the most common conditions in older cats, CKD is the progressive loss of kidney function over time. Healthy kidneys perform many important functions, most notably filtering the blood and making urine, so problems with kidney function can result in a variety of health problems for cats. Cats with CKD often have a loss of appetite.
The active ingredient in Elura is capromorelin which mimics the action of a naturally-occurring hormone called ghrelin. Ghrelin affects many organs throughout the body, and Elura may affect these same organs. The drug is known to make cats eat more and to also affect their metabolism, resulting in weight gain.
Elura is an oral solution that you give directly into your cat’s mouth once daily using a special dosing syringe. After starting your cat on Elura, you should watch for changes in how much she eats and drinks and in her behavior and activity level. Some cats on Elura become less active and may have weakness. Also watch for digestive problems, such as vomiting, diarrhea, drooling.
Elura may increase blood sugar levels for several hours after a dose, so it may not be appropriate to use in cats that currently have diabetes mellitus or have had diabetes in the past. The drug should not be used in cats with a condition called acromegaly, in which the pituitary gland in the brain produces too much growth hormone.
Veterinarians should use caution when prescribing Elura for cats that have heart disease or are severely dehydrated. The drug causes a cat’s heart rate and blood pressure to go down for several hours after a dose. Veterinarians should also use caution when prescribing Elura for cats with liver disease because the drug is metabolized in the liver.
Semintra for Controlling High Blood Pressure in Cats
Kidney disease and hyperthyroidism (elevated thyroid hormone levels) are the two most common causes of high blood pressure (hypertension) in cats. Certain heart diseases can also cause high blood pressure in cats. Sometimes, no underlying cause is identified. When left untreated, high blood pressure can damage your cat’s eyes, kidneys, heart, and brain and central nervous system.
Semintra is the first, and so far only, FDA-approved drug to control high blood pressure in cats. The active ingredient in Semintra is telmisartan and it lowers blood pressure by relaxing blood vessels.
Semintra is an oral solution that you give either directly into your cat’s mouth or on top of a small amount of food. Don’t mix the solution into the food. Initially, you give the drug twice a day for 14 days and then once a day. To prevent giving an incorrect dose, only use the special dosing syringe provided in the package. The dosing syringe fits into the bottle opening and has clear marks for measuring the dose.
Your veterinarian should check your cat’s blood pressure regularly after starting Semintra and adjust the dose as needed to keep his blood pressure at the best level. Veterinarians should monitor cats with kidney disease early in treatment for potential worsening of their kidney values. When starting treatment, veterinarians should monitor all cats for anemia (low level of red blood cells) and a decreased appetite resulting in weight loss. Other common side effects of Semintra include vomiting, diarrhea, and a decreased activity level.
Pregnant women should avid any contact with Semintra because other similar drugs have been found to harm the unborn baby during pregnancy.
Your veterinarian should give you a Client Information Sheet every time you receive a prescription for Semintra, whether it’s the first time your cat is receiving the drug or it’s the 15th refill. The Client Information Sheet for Semintra is written specifically for cat owners, in a user-friendly, question-and-answer format. The handout gives you detailed information about Semintra and its side effects, helping you use the drug as safely and effectively as possible in your cat.
FDA encourages you to call your veterinarian if you think your cat is having a side effect from Mirataz, Elura, or Semintra. A side effect associated with a drug is called an adverse event. Adverse events also include a lack of effectiveness (the drug doesn’t do what it’s supposed to do) and reactions in people who handle the drug. Call your healthcare provider if you have a reaction to Mirataz, Elura, or Semintra.
FDA also encourages you to work with your veterinarian to report any adverse event—in either pets or people—associated with Mirataz, Elura, or Semintra or any product defect such as a problem with the dosing syringe for Elura or Semintra or the drug is off-color. How to Report Animal Drug and Device Side Effects and Product Problems.
Remember to keep Mirataz, Elura, and Semintra in a secure location out of reach of children, dogs, cats, and other animals to prevent accidental ingestion or overdose.
Benefit of FDA Approval
Knowing a drug is safe, effective, and high-quality is the benefit of FDA approval. During the approval process for an animal drug, the agency evaluates information submitted by the drug company to make sure the drug is safe and effective for its intended use and that the drug is properly manufactured and adequately labeled and packaged.
FDA-approved Mirataz, Elura, and Semintra have been shown to be safe and effective in cats when used according to the directions on the label. Each drug’s label provides dosing and safety information specific to cats. The drugs are also properly manufactured and adequately packaged.
Resources for You
For More Information
Contact FDA’s Center for Veterinary Medicine at either AskCVM@fda.hhs.gov or 240-402-7002.