From the FDA Drug Label
What are the possible side effects of Losartan Potassium Tablets? Losartan Potassium Tablets may cause the following side effects that may be serious: • Injury or death of unborn babies. • Allergic reaction. Symptoms of an allergic reaction are swelling of the face, lips, throat or tongue. Get emergency medical help right away and stop taking Losartan Potassium Tablets. • Low blood pressure (hypotension). Low blood pressure may cause you to feel faint or dizzy. Lie down if you feel faint or dizzy. Call your doctor right away • For people who already have kidney problems, you may see a worsening in how well your kidneys work. Call your doctor if you get swelling in your feet, ankles, or hands, or unexplained weight gain • High blood levels of potassium The most common side effects of Losartan Potassium Tablets in people with high blood pressure are: • “colds” (upper respiratory infection) • dizziness • stuffy nose • back pain The most common side effects of Losartan Potassium Tablets in people with type 2 diabetes with diabetic kidney disease are: • diarrhea • tiredness • low blood sugar • chest pain • high blood potassium • low blood pressure
The side effects of Losartan (Angiotensin II receptor antagonist) include:
- Serious side effects:
- Injury or death of unborn babies
- Allergic reaction
- Low blood pressure (hypotension)
- Worsening kidney problems
- High blood levels of potassium
- Common side effects in people with high blood pressure:
- Upper respiratory infection
- Dizziness
- Stuffy nose
- Back pain
- Common side effects in people with type 2 diabetes with diabetic kidney disease:
- Diarrhea
- Tiredness
- Low blood sugar
- Chest pain
- High blood potassium
- Low blood pressure 1
From the Research
Losartan can cause several side effects, including dizziness, headache, and upper respiratory infections, but the most recent and highest quality study 2 suggests that it may also cause tremors and dysarthria in some patients.
Common Side Effects
The most common side effects of losartan include:
- Dizziness
- Lightheadedness
- Fatigue
- Headache
- Upper respiratory infections like cough or cold symptoms These side effects are generally mild and temporary, but patients should contact their healthcare provider if they experience severe or persistent symptoms.
Less Common Side Effects
More serious but less common side effects of losartan include:
- High potassium levels (hyperkalemia)
- Kidney problems
- Allergic reactions
- Angioedema (swelling of the face, lips, tongue, or throat) Rarely, losartan can cause liver problems or a decrease in white blood cells.
Special Considerations
Pregnant women should not take losartan as it can cause harm to the developing fetus, particularly in the second and third trimesters. Patients with a history of ACE inhibitor-related cough may be at lower risk of developing a cough while taking losartan, as it is associated with a similar incidence of cough to placebo 3.
Tolerability and Safety
Losartan is generally well tolerated, with a favorable safety profile compared to other antihypertensive agents 4, 5. However, patients should be monitored for signs of adverse effects, such as severe dizziness, fainting, swelling of the face or extremities, yellowing of the skin or eyes, unusual bruising or bleeding, persistent cough, or signs of infection. Overall, the benefits of losartan in reducing blood pressure and stroke risk outweigh the risks of side effects, making it a valuable treatment option for patients with hypertension and left ventricular hypertrophy 6.