Telmisartan for Cats: Overview, Dosage & Side Effects

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Telmisartan is a medication that helps lower blood pressure when it is abnormally high, which is called hypertension. Hypertension can be a very dangerous health condition and treating it effectively is very important. Read further to learn more about telmisartan and how it is used for hypertensive cats.

Telmisartan for Cats Overview

Medication Type:

Angiotensin receptor blocker (ARB), anti-hypertensive

Form:

Liquid (FDA approved brand Semintra) and tablets

Prescription Required?:

Yes

FDA Approved?:

Yes, but only the liquid brand Semintra

Life Stage:

Adult and senior cats

Brand Names:

Semintra, Micardis

Common Names:

Telmisartan

Available Dosages:

10mg/ml oral solution (Semintra), 4mg/ml oral solution (available outside the US); oral tablets in 20mg, 40mg, and 80mg size (Micardis and generic tablets)

About Telmisartan for Cats

Telmisartan is called an angiotensin receptor blocker, or ARB. The maintenance and balance of blood pressure is a very complicated series of events and always being adjusted by multiple processes in the body.

Telmisartan works by blocking a receptor called angiotensin 1 (AT1), which leads to dilation of blood vessels and adjustment in potassium and sodium levels that lead to lower blood pressure.

Telmisartan is considered more effective at reducing blood pressure in cats compared to ACE inhibitors (ACEi) like benazepril. On average, it reduces blood pressure by about 25 mmHg.

High blood pressure, or systemic hypertension, is considered medically significant at levels at or exceeding 160 mmHg. A long-term study evaluating hypertensive cats for 6 months found that telmisartan was very effective at controlling blood pressure consistently when starting between 160 mmHg and 200 mmHg.

The study did not include cats with blood pressures exceeding 200 mmHg given safety concerns for the placebo group of cats who were not receiving medication. However, the study authors surmised that had these cats been included, telmisartan would have been as equally effective.

Amlodipine is another anti-hypertensive medication that is commonly used for cats with high blood pressure. Amlodipine may still be a first choice by many veterinarians, especially for extremely hypertensive cats, as it may be more effective overall at reducing blood pressure by about 30-50 mmHg.

There are some cases where telmisartan may be used in place of amlodipine or they may be used together. If amlodipine leads to unwanted side effects, telmisartan may be the next best choice. In cases where further increasing an amlodipine dose is not desired, telmisartan may be added.

While hypertension secondary to kidney disease is more common in dogs, this may be seen in cats. Any blood pressure medication has the potential to worsen kidney disease but the ability for anti-hypertensives to reduce protein loss through the urine (proteinuria) is also very important. In these cases, it may be better to balance lower doses with two separate medications (like pairing benazepril and telmisartan) than to use a very high dose of a single medication.

Dosing Information for Cats

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Telmisartan is FDA approved for treating feline hypertension under the brand name Semintra. It is the only medication FDA approved for cats for treating high blood pressure.

Semintra comes as a 10 mg/ml oral solution with its own dosing syringe. A 4mg/ml telmisartan oral solution (requiring a higher volume) is available outside of the United States.

Telmisartan does also come in an oral tablet form. The most common brand name is Micardis, with generics also available. This form is not FDA approved for use in cats but may be chosen as an extra-label option by your vet depending on cost and dosing methods that work best for your kitty. Off-label use of medications is very common in veterinary medicine.

For Semintra, the FDA labeled dose is 1.5 mg/kg (0.68 mg/lb) by mouth every 12 hours for the first 14 days, then increased to 2mg/kg (0.91 mg/lb) once daily.

Blood pressure medication doses should only be adjusted based on recheck blood pressure measurements with your veterinarian. If blood pressure is found to be too low during a recheck, the dose may be reduced by 0.5 mg/kg (0.23 mg/lb) at a time.

The following table provides approximate volume doses for the 10 mg/ml concentration Semintra based on 2.5 lb weight increments. The syringe Semintra comes with has volume measurements in 0.1 ml amounts.

These volume doses are designed to provide guidance only and should not be considered a replacement for your own veterinarian’s dosing and instructions. These weights may not match your own cat’s weight exactly and exact dosing is very important. Dosing adjustments for blood pressure medication should only be adjusted based on recheck blood pressure measurements. Doses should never be adjusted without your veterinarian’s guidance.

How to Administer Telmisartan to Cats

Semintra, the FDA approved form of telmisartan for cats, is a liquid medication that can be given by syringe. Chris Vanderhoof / Cats.com

Semintra is an oral liquid. The FDA label indicates it may be given either directly by mouth or added on top of a small amount of food (not mixed in with food). This method of oral administration may be easier for many cat owners, especially if only small volumes are needed.

Generic telmisartan only comes in a tablet form. For additional help in administering a pill to your cat, see the following links for how to hide pills in food or administering a pill directly by mouth.

• The 7 Best Cat Foods to Hide Pills In
• How to Give Your Cat a Pill (With 7 Proven Tips!)

Side Effects of Telmisartan for Cats

Telmisartan is generally well-tolerated. In FDA field studies, the most commonly reported adverse events were gastrointestinal-related, including:

• Vomiting
• Diarrhea

Weight loss was also a common finding during studies. It was more common over the 6 month field study vs. the 30 day field study and may have been related more to other concurrent disease conditions the predominantly elderly cats had (such as chronic kidney disease).

Dehydration, reduced appetite, and lethargy were also found in both field studies in lower percentages.

Hypotension (low blood pressure) occurred in up to a quarter of patients, requiring a dosage adjustment.

Non-regenerative anemia (where red blood cells are not regenerating) was seen in 5-15% of cats in the studies. Non-regenerative anemias are usually more mild, do not progress quickly, are very non-specific and common to see in cats secondary to many underlying disease conditions.

Telmisartan should not be used in pregnant queens. Use in cats with significant liver disease should be approached very cautiously with additional close bloodwork monitoring.

Overdose and Emergencies

Little is known about acute overdoses of telmisartan in cats, but hypotension (low blood pressure) would be expected. A cat with an acute overdose may have the following appearance:

• lethargic
• not interested in food
• trembling
• vomiting

Over the long-term, in cats receiving 5 times the recommended dose (5mg/kg/day) the most common effects seen included:

• hypotension
• decreased red blood cell count
• reduced food intake

If you suspect your cat received an overdose of telmisartan make sure to immediately contact one or more of the following for advice:

• Your veterinarian
• ASPCA Animal Poison Control Center (1-888-426-4435)
• Pet Poison Helpline (1-855-764-7661)

Potential Drug Interactions With Telmisartan

There are several medications that may interact with telmisartan. Unless indicated, interactions don’t always mean these medications cannot be used together, but may require dose adjustment or close monitoring. This is especially true when two blood pressure medications are used together to control hypertension.

• Ace Inhibitors (ACEi) (benazepril, enalapril): increased risk for hypotension, kidney function changes, close monitoring is warranted
• Aspirin: may reduce antihypertensive effects and increase risk for kidney impairment
• Benzodiazepines (diazepam, alprazolam): may increase risk of hypotension
• Buspirone: may increase risk for hypotension
• Cabergoline: may increase risk for hypotension
• Corticosteroids: (prednisolone): may decrease the antihypertensive effects of angiotensin receptor blockers like telmisartan
• Dexmedetomidine: may result in additive effects on blood pressure (increases) and heart rate (decreases)
• Diazoxide: may increase risk for hypotension
• Dichlorphenamide: may increase risk for hypotension
• Digoxin: may increase digoxin levels, requires close monitoring
• Diphenhydramine (Benadryl): may increase risk for hypotension
• Doxepin: may increase risk for hypotension
• Insulin: may increase risk for hypoglycemia
• Heparin (dalteparin, enoxaparin): may increase risk for increased potassium levels
• Non-steroidal anti-inflammatory drugs (NSAIDs) (meloxicam, Onsior): possible reduced antihypertensive effects and increased risk for kidney impairment. Increased monitoring is warranted.
• Opioids (buprenorphine, tramadol): may increase risk for hypotension
• Potassium salts (potassium bromide): increased risk for increased potassium levels, increased monitoring is warranted.
• Potassium-sparing diuretics (spironolactone): increased risk for higher potassium levels, increased monitoring is warranted.

How to Store Telmisartan

Telmisartan solution for cats (Semintra) should be stored at room temperature (at or below 77 degrees F (25 degrees C). Short excursions up to 107 degrees F (40 degrees C) are permitted.

The shelf life for Semintra is 6 months after the bottle is opened.

Generic telmisartan tablets may be stored at room temperature up to 86 degrees F (30 degrees C). If packaged in blister packs, they should not be removed until right before they are given.