Lisinopril side effects


Lisinopril, marketed under the brand names Prinivil® and Zestril®, belongs to a group of drugs called “ACE inhibitors,” which work by inhibiting angiotensin-converting enzyme (ACE). ACE is responsible for converting the hormone angiotensin I to angiotensin II. Reducing the production of angiotensin II lowers blood pressure because angiotensin II is a potent vasoconstrictor. In other words, angiotensin II causes blood vessels to constrict. Much like pinching a garden hose increases the pressure of the water inside the hose, constricting a blood vessel increases blood pressure.

Furthermore, angiotensin II has the downstream effect of triggering aldosterone secretion from the adrenal glands. Aldosterone, a mineralocorticoid, promotes the retention of sodium, which ultimately leads to fluid retention and increases blood pressure. Therefore, by inhibiting ACE, we reduce blood pressure by two mechanisms (a reduction in the production of both angiotensin II and aldosterone).


The probability that a person will experience side effects while taking lisinopril is approximately 15.5%. In other words, one person will experience one or more side effects for every six people taking lisinopril.


Most of the side effects of lisinopril stem directly from lisinopril’s mechanism of action. For example, the most common side effect of lisinopril, a dry cough (also sometimes called a “nonproductive cough”), stems from the fact that lisinopril inhibits another enzyme called kininase II which is identical to ACE. Since kininase II is responsible for the breakdown of bradykinin, the consequence of inhibiting kininase II is the accumulation of bradykinin, which triggers a dry cough in around 4% of people who take lisinopril.


A potentially serious and yet relatively common side effect of lisinopril is hyperkalemia (high potassium in the blood). Much like a dry cough, hyperkalemia is also a direct consequence of lisinopril’s mechanism of action. When the production of angiotensin II is reduced, as is the case for those taking lisinopril, the amount of aldosterone secreted by the adrenal glands is also reduced. Aldosterone is like a signal to the kidneys to retain sodium in the blood at the expense of potassium. In other words, potassium is removed from the blood and placed into the urine in exchange for sodium, which is removed from the fluid that will become urine and directed back into the bloodstream. Since lisinopril reduces aldosterone secretion, there is a relative decrease in blood sodium levels and a corresponding increase in blood potassium levels.

A normal serum potassium level would be something in the ballpark of 3.5-5.0 mEq/L. The average patient who takes lisinopril will experience an increase in serum potassium of only 0.1 mEq/L; however, 6% of patients with normal kidney function will experience an exaggerated rise in serum potassium levels (i.e., > 0.5 mEq/L). For this reason, healthcare providers must monitor electrolyte levels (including potassium levels) in patients taking lisinopril.

Why might an elevated potassium level be cause for Concern? Because hyperkalemia (serum potassium > 5.0-5.5 mEq/L) can lead to dangerous cardiac arrhythmias.

The probability of hyperkalemia in patients taking lisinopril ranges from 2.2-4.8% on average.2 Several factors can increase the risk of hyperkalemia. Examples include:

  • Renal insufficiency (poor kidney function)
  • Diabetes
  • Potassium-sparing diuretics (spironolactone, eplerenone, triamterene, or amiloride)
  • Potassium supplements (K-Dur®, Klor-Con®, and others)
  • Potassium-containing salt substitutes.


Hypotension (low blood pressure) is defined as a blood pressure reading of less than 90/60 mmHg. The lack of adequate blood flow that results from hypotension can damage vital organs. Additionally, fainting can also occur, which can lead to head injuries and broken bones. In uncomplicated patients taking lisinopril alone for blood pressure control, the risk of hypotension is about 0.8%. Meanwhile, complicated patients (e.g., those with other heart disease and kidney disease) taking lisinopril, especially when taking lisinopril combined with other blood pressure-lowering medication(s), have a roughly 11% risk of developing hypotension. Risk factors for hypotension with lisinopril include dehydration, excessive sweating, vomiting, and diarrhea. Note that these factors could lead to volume depletion (a significant drop in blood volume).


Hypoglycemia (low blood sugar) is something to watch out for with lisinopril, particularly in patients taking oral anti-diabetic medications, insulin injections, and those with impaired kidney function. The risk of hypoglycemia is highest in the first 30 days after starting lisinopril.


Other common side effects of lisinopril include dizziness (2.3%), headache (2.1%), asthenia (1.7%), and nausea (1%).


Angioedema (often characterized by swelling in the eyes, lips, and tongue) is a rare reaction to lisinopril; however, if the throat becomes swollen, this condition can be life-threatening. Fortunately, the risk of angioedema due to lisinopril is only about 0.01% (or 1 in 10,000). Females, African Americans, and cigarette smokers may have a higher risk of angioedema with lisinopril.


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Lisinopril [package insert]. Indianapolis, IN: Northwind Pharmaceuticals; 2014.

Huckell VF, Bélanger LG, Kazimirski M, Subramanian T, Cox AJ. Lisinopril in the treatment of hypertension: a Canadian postmarketing surveillance study. Clin Ther. 1993;15(2):407-422.

Brown T, Gonzalez J, Monteleone C. Angiotensin-converting enzyme inhibitor-induced angioedema: A review of the literature. J Clin Hypertens (Greenwich). 2017;19(12):1377-1382. doi:10.1111/jch.13097

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