How does candesartan work?

Candesartan is a medication used to lower blood pressure.  How does candesartan work, what is it used for, and what are the potential side effects?

Candesartan is a prescription medication, and it belongs to the angiotensin II receptor blocker (ARB) class of pharmaceuticals.¹  It is available in pill form or liquid, and this chemical compound is converted by the body to its active form once ingested.¹  Candesartan is usually taken once daily in doses between 4 and 32 milligrams (mg).

Candesartan can be prescribed for a variety of reasons.  It is indicated by the FDA as a treatment for hypertension, or high blood pressure, in adults and children over the age of 1.²  It is also indicated by the FDA as a treatment for heart failure, as studies suggest that, when combined with other therapies, it can help reduce the risk of mortality in patients with chronic heart failure.^2,3,4 

In addition to these FDA-approved indications, candesartan may also be prescribed off-label to treat a variety of conditions such as diabetic nephropathy or migraines.^1,5,6  More research is needed to determine the effectiveness of candesartan in treating these conditions.

How does candesartan work?

Candesartan and other ARB medications work by preventing the binding of a hormone called angiotensin II to angiotensin II receptor type 1, which is one of the receptors that angiotensin II binds to.¹  The binding of this hormone to this receptor, which takes place in the smooth muscle surrounding the blood vessels, causes the blood vessels to constrict.^1,  The constriction of the blood vessels is then associated with an increase in blood pressure because there is less space for the blood to flow through.

Binding of the angiotensin II receptor type 1 is also associated with the release of aldosterone and the reabsorption of sodium.^1,7,8  Both of these processes can lead to increased water retention, which can lead to further increases in blood pressure.  By blocking the binding of angiotensin II to the angiotensin II receptor type 1, candesartan helps prevent these changes from taking place and, in turn, can help reduce blood pressure. 

Side effects of candesartan

ARBs such as candesartan do not appear to be associated with one particular adverse effect associated with angiotensin-converting enzyme (ACE) inhibitors, which is cough.^1,10  However, it may be associated with some side effects in some people.  One potential side effect is hypotension, or low blood pressure; given that candesartan is a medication that lowers blood pressure, it may decrease blood pressure too much in some individuals.^1,9,11 

Another potential side effect is hyperkalemia, which is an abnormally high level of potassium in the blood.^1,11,12  This risk is elevated for some populations, including older adults, males, individuals with certain underlying conditions, and those who regularly use reduced-sodium salt substitutes containing potassium.¹²  These side effects can potentially be dangerous, so it is important to monitor blood pressure and blood potassium levels for individuals taking ARBs such as candesartan.

Some other reported side effects may include headache, dry skin, nausea, and abdominal pain, among others.¹¹  Candesartan may also be harmful to a developing fetus during pregnancy, and it is not recommended for use during pregnancy.^1,11,13   It is important to tell your healthcare provider about any side effects that you are concerned about when taking candesartan.  Seek medical help immediately if you experience signs of an allergic reaction after taking candesartan, such as chest tightness, hives, or swelling of the face, mouth, or throat.

Candesartan can also interact with a variety of medications, including certain diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, potassium supplements, and lithium.¹¹  For this reason, it is important to tell your healthcare provider about all medications and supplements that you are taking.

This article is not medical advice, and it is not intended to prescribe, diagnose, or promote specific treatments for any condition.

References

1. Bulsara, K.G., Makaryus, A.N. (2021, July 13). Candesartan. StatPearls [Internet]. Accessed 2021, July 23, from https://www.ncbi.nlm.nih.gov/books/NBK519501/#:~:text=Candesartan%20is%20an%20oral%20angiotensin,absorption%20to%20its%20active%20form.
2. FDA Access Data (2015, February). Atacand. AstraZeneca; ref: 3698709. Accessed 2021, July 26, from https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/020838s036lbl.pdf
3. Ripley, T.L., Chonlahan, J.S., Germany, R.E. (2006, December). Candesartan in heart failure. Clin Interv Aging 1(4): 537-366. Doi: 10.2147/ciia.2006.1.4.357
4. Young, J.B., Dunlap, M.E., Pfeffer, M.A., et al (2004, October 18). Mortality and Morbidity Reduction with Candesartan in Patients with Chronic Heart Failure and Left Ventricular Systolic Dysfunction. Circulation 110: 2618-2626. Doi: 10.1161/01.CIR.0000146819.43235.A9
5. Takao, T., Horino, T., Kagawa, T., et al (2011). Possible involvement of intracellular angiotensin II receptor in high-glucose-induced damage in renal proximal tubular cells. J Nephrol 24(2): 218-224. Doi: 10.5301/jn.2010.5785
6. Feher, G., Pusch, G. (2015). [Role of antihypertensive drugs in the treatment of migraine]. Orv Hetil 156(5): 179-185. Doi: 10.1556/OH.2015.30056
7. Guo, D.F., Sun, Y.L., Hamet, P, et al (2001). The angiotensin II type 1 receptor and receptor-associated proteins. Cell Research 11: 165-180. Doi: 10.1038/sj.cr.7290083
8. Scott, J.H., Menouar, M.A., Dunn, R.J. (2021, February 15). Physiology, Aldosterone. StatPearls [Internet]. Accessed 2021, July 27, from https://www.ncbi.nlm.nih.gov/books/NBK470339/
9. Lund, L.H., Clagget, B., Liu, J., et al (2018). Heart failure with mid-range ejection fraction in CHARM: characteristics, outcomes and effect of candesartan across the entire ejection fraction spectrum. European Journal of Heart Failure 20(8): 1230-1239. Doi: 10.1002/ejhf.1149
10. Powers, B.J., Coeytaux, R.R., Dolor, R.J., et al (2012, June). Updated report on comparative effectiveness of ACE inhibitors, ARBs, and direct renin inhibitors for patients with essential hypertension: much more data, little new information. J Gen Intern Med 27(6): 716-729. Doi: 10.1007/s11606-011-1938-8
11. Husain, A., Azim, S., Mitra, M., et al (2011). A review on candesartan: pharmacological and pharmaceutical profile. Journal of Applied Pharmaceutical Science 1(10): 12-17. Accessed online.
12. Desai, A.S., Swedberg, K., McMurray, J.V., et al (2007). Incidence and predictors of hyperkalemia in patients with heart failure: an analysis of the CHARM program. J Am Coll Cardiol 50(20): 1959-1966. Accessed online from https://www.jacc.org/doi/full/10.1016/j.jacc.2007.07.067
13. Hunseler, C., Paneitz, A., Friedrich, D., et al (2011). Angiotensin II receptor blocker induced fetopathy: 7 cases. Klin Padiatr 223(1): 10-14. Doi: 10.1055/s-0030-1269895.
14. Image by Bruno /Germany from Pixabay