Mar Vista Animal Medical Center

3850 Grand View Blvd.
Los Angeles, CA 90066




(for veterinary information only)



20 mg, 40 mg and 80 mg


Telmisartan is a member of a class of medications known as the ARBs (Angiotensin II Receptor Blockers), a class that has been around in human medicine since the mid-1990's. Recently, telmisartan received FDA approval for the treatment of high blood pressure in cats but more commonly it is used in the treatment of inappropriate urinary protein loss (glomerular disease).

So how does that work and how are those two conditions even related? The answer is AngiotensinII, a biochemical designed to maintain your blood pressure in times of blood loss. The problem is that your body thinks that any drop in blood pressure generates angiotensin II. This would be great if you were in hand to hand combat against a predator but not great if you are having heart failure. Also, if you have high blood pressure for any of a number of reasons, you don't need any angiotensin II around making things worse.

Angiotensin II brings up blood pressure in many ways: narrowing blood vessels, generating other hormones, causing sodium to be retained and more. Part of its actions include altering the circulation through the kidneys. More specifically, angiotensin II alters the way blood flows through the nephrons in the kidneys, the nephrons being the function units of the kidneys that are busily filtering out toxins, balancing electrolytes etc. In diseases where the nephron's filtration mechanisms are damaged and proteins are lost inappropriately in urine, angiotensin II makes things worse and inhibiting the actions of angiotensin II is helpful. This is often done with angiotensin converting enzyme inhibitors (like benazepril, or enalapril). Sometimes these are not enough or the patient does not tolerate them so in these cases ARB's like telmisartan come in handy.



This medication is typically given once a day with or without food. Monitoring blood pressure, kidney function and urinary protein loss should be expected to assess how well the medication is working. Monitoring tests will be on-going so be sure you understand the schedule your veterinarian has recommended.

Because red blood cell loss can be a side effect, red blood cell counts should be monitored every 3- 6 months as well.



The full side effects profile is still being worked out for pets. Low blood pressure (manifesting as weakness or even fainting) is possible with any medication that reduces blood pressure.

Upset stomach (vomiting, diarrhea, appetite loss) should be reported to your veterinarian if persistent.

Telmisartan is not considered to be safe in pregnancy and should not be handled by pregnant women (wear gloves and wash hands after administration).



Concurrent use of telmisartan with any of the following medications can further drop blood pressure:

If telmisartan is used with Non-Steroidal Anti-Inflammatory medications, monitoring of kidney function becomes especially important and the monitoring test interval may become more frequent.



The biggest concerns stems from the newness of this medicine in veterinary practice. The side effects potential is still being described.

  • Telmisartan is not safe for use in pregnancy.
  • Telmisartan could be a problem for patients with moderate to severe liver disease.
  • Telmisartan should be stored at room temperature in a light-tight container (such as a pharmacy bottle or the container from the manufacturer).
  • If a dose is accidentally skipped, do not attempt to double up on the next dose.


Page posted: 3/4/2021