Losartan Side Effects

Medically reviewed by Drugs.com. Last updated on Oct 28, 2024.

Applies to losartan: oral tablet.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Dizziness or lightheadedness may occur after the first dose of this medicine, especially if you have been taking a diuretic (water pill). Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.

Check with your doctor right away if you become sick while taking this medicine, especially if you have severe or continuing nausea, vomiting, or diarrhea that does not stop. These conditions may cause you to lose too much water and may lead to low blood pressure. You can also lose water by sweating, so drink plenty of water during exercise or in hot weather.

Ask your doctor before you use medicines, supplements, or salt substitutes that contain potassium.

Avoid alcoholic beverages until you have discussed their use with your doctor. Alcohol may make the low blood pressure effect worse or increase the possibility of dizziness or fainting.

Do not take other medicines unless they have been discussed with your doctor. This especially includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.

Serious side effects of losartan

Along with its needed effects, losartan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking losartan:

Other side effects of losartan

Some side effects of losartan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to losartan: oral suspension, oral tablet.

General adverse events

The most common adverse reactions were upper respiratory infection and dizziness.^[Ref]

Respiratory

• Common (1% to 10%): Nasal congestion, upper respiratory infection, sinusitis, pharyngitis, cough, sinus disorder
• Uncommon (0.1% to 1%): Dyspnea
• Frequency not reported: Bronchitis, pharyngeal discomfort, epistaxis, rhinitis, respiratory congestion^[Ref]

Gastrointestinal

• Common (1% to 10%): Abdominal pain, nausea, diarrhea, dyspepsia
• Uncommon (0.1% to 1%): Obstipation, vomiting
• Frequency not reported: Constipation, dental pain, dry mouth, flatulence, gastritis^[Ref]

Musculoskeletal

• Common (1% to 10%): Muscle cramp, back pain, leg pain, myalgia
• Frequency not reported: Arm pain, hip pain, joint swelling, knee pain, musculoskeletal pain, shoulder pain, stiffness, arthralgia, arthritis, fibromyalgia, muscle weakness
• Postmarketing reports: Rhabdomyolysis^[Ref]

Renal

• Common (1% to 10%): Renal impairment, renal failure, BUN increased, serum creatinine increased^[Ref]

Nervous system

• Common (1% to 10%): Dizziness, headache, vertigo
• Uncommon (0.1% to 1%): Somnolence
• Rare (less than 0.1%): Paresthesia, syncope, cerebrovascular accident
• Frequency not reported: Ataxia, hypesthesia, memory impairment, migraine, peripheral neuropathy, tremor, taste perversion, tinnitus^[Ref]

Other

• Common (1% to 10%): Asthenia/fatigue, edema/swelling, chest pain
• Frequency not reported: Facial edema, fever, orthostatic effects
• Postmarketing reports: Malaise^[Ref]

Metabolic

• Common (1% to 10%): Hyperkalemia, serum potassium increased, hypoglycemia
• Frequency not reported: Anorexia, gout
• Postmarketing reports: Hyponatremia^[Ref]

Cardiovascular

• Common (1% to 10%): Orthostatic hypotension
• Uncommon (0.1% to 1%): Palpitation, angina pectoris
• Rare (less than 0.1%): Atrial fibrillation
• Frequency not reported: Second degree atrioventricular block, hypotension, myocardial infarction, sinus bradycardia, tachycardia, ventricular tachycardia, ventricular fibrillation, flushing
• Postmarketing reports: Vasculitis^[Ref]

Psychiatric

• Common (1% to 10%): Insomnia
• Uncommon (0.1% to 1%): Sleep disorder
• Frequency not reported: Anxiety, anxiety disorder, confusion, depression, dream abnormality, libido decreased, nervousness, panic disorder^[Ref]

Hematologic

• Common (1% to 10%): Anemia
• Rare (less than 0.1%): Hemolysis
• Postmarketing reports: Thrombocytopenia, hemoglobin decreased, hematocrit decreased^[Ref]

Dermatologic

• Uncommon (0.1% to 1%): Urticaria, pruritus, rash
• Rare (less than 0.1%): Angioedema, superficial peeling of palms
• Frequency not reported: Alopecia, dermatitis, dry skin, ecchymosis, erythema, photosensitivity, sweating
• Postmarketing reports: Erythroderma^[Ref]

Hepatic

• Rare (less than 0.1%): ALT increased
• Postmarketing reports: Hepatitis, liver enzymes increased, serum bilirubin increased, pancreatitis, liver function abnormalities^[Ref]

Genitourinary

• Frequency not reported: Impotence, nocturia, urinary frequency, urinary tract infection^[Ref]

Ocular

• Frequency not reported: Blurred vision, burning/stinging in the eye, conjunctivitis, visual acuity decreased^[Ref]

Immunologic

• Frequency not reported: Flu-like symptoms
• Postmarketing reports: Anaphylactic reactions, hypersensitivity reactions^[Ref]

See also:

Frequently asked questions

• Can you eat bananas when taking losartan?
• Does Losartan block the receptor used by the Coronavirus?
• Losartan vs Valsartan - What's the difference between them?
• Does losartan cause rapid heart rate, irregular heartbeat or low blood pressure?
• Are losartan and losartan potassium the same or different drugs?

Further information

Losartan side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer