Losartan Side Effects

Medically reviewed by Drugs.com. Last updated on Oct 26, 2023.

Applies to losartan: oral tablet.

Important warnings This medicine can cause some serious health issues

Oral route (tablet)

When pregnancy is detected, discontinue losartan as soon as possible.

Drugs that act directly on the renin-angiotensin system can cause injury or death to the developing fetus.

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:

Less common

• blurred vision
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• confusion
• difficult breathing
• dizziness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fainting
• fast or irregular heartbeat
• nausea or vomiting
• nervousness
• numbness or tingling in the hands, feet, or lips
• stomach pain
• sweating
• unusual tiredness or weakness
• weakness or heaviness of the legs

Incidence not known

• black, tarry stools
• bleeding gums
• blood in the urine or stools
• coma
• convulsions
• cough
• decreased urine output
• difficulty swallowing
• headache
• hives, itching, skin rash
• increased thirst
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• muscle pain or cramps
• pinpoint red spots on the skin
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• tightness in the chest
• unusual bleeding or bruising

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:

Less common

• body aches or pain
• chills
• continuing ringing or buzzing or other unexplained noise in the ears
• decreased interest in sexual intercourse
• difficulty having a bowel movement (stool)
• ear congestion
• feeling of constant movement of self or surroundings
• feeling sad or empty
• headache, severe and throbbing
• hearing loss
• inability to have or keep an erection
• increased sensitivity of the skin to sunlight
• irritability
• lack of appetite
• loss in sexual ability, desire, drive, or performance
• loss of interest or pleasure
• loss of voice
• redness or other discoloration of the skin
• sensation of spinning
• severe sunburn
• sneezing
• sore throat
• stuffy or runny nose
• trouble concentrating
• trouble sleeping

Incidence not known

• change or loss of taste
• dark urine
• general tiredness and weakness
• light-colored stools
• yellow eyes and skin

For healthcare professionals

Applies to losartan: oral tablet.

General

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]

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.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer