Skip to content
Call a poison centerGet help online
Loading Theme Toggle

Uses and side effects of losartan

Test Image

The bottom line

Losartan (Cozaar®) is a common medication used to lower blood pressure. It is typically well-tolerated and doesn’t interact with many drugs, foods, or supplements. Losartan may cause side effects, including fatigue, dizziness, and fainting. It is not safe to use during pregnancy, and can have dangerous effects if excessive amounts are consumed.

Prevention Tips

  • Use child-resistant containers for all medications, prescription and nonprescription. Keep in mind that these closures are child-resistant, not child proof.

  • Keep medications in locations that are out of sight and hard to reach for children. 

  • Talk with your doctor if you experience side effects while taking medications.

  • Keep a current list of all medications, supplements, and vitamins that you are taking. 

This Really Happened

A 3-year-old boy found his mother’s bottle of losartan 25 mg tablets that had been left on the counter. He chewed and swallowed 8 pills. He vomited once, developed a rash on his arms, and became dizzy. He was taken to a hospital where he was admitted for observation. He experienced low blood pressure readings over the next several hours, but by the next morning he had recovered completely and was able to be discharged home.

Poisoned? Get expert help.

Don't guess what you should do. Get accurate answers online or by phone. Both ways are free and confidential.

Get help online

Support Us

Your donation to our 501(c)(3) organization enables us to help those who prefer to go online when faced with a poison emergency. Our webPOISONCONTROL online tool and app is a free, confidential, quick and easy way to get expert help. It has guided more than a million users faced with a poison emergency. 

DONATE NOW

Subscribe to The Poison Post®

The Poison Post® is a free, quarterly
e-newsletter delivering poison prevention tips right to your inbox!

Subscribe

Connect with us on social media!

Follow us on Facebook, X, Instagram, and our other social platforms for news and updates.

What is losartan used for?

Losartan is a prescription drug primarily used to treat high blood pressure (hypertension). It is also prescribed as a treatment for conditions that affect the heart, kidneys, and blood vessels, such as heart failure and chronic kidney disease. Losartan works by relaxing the blood vessels throughout the body. This, in turn, reduces the workload of the heart and kidneys. Losartan is approved by the US Food and Drug Administration (FDA) to treat hypertension in adults and children and kidney disease in diabetics. Losartan is also used to reduce the risk of stroke in people with certain health conditions.

Lisinopril vs. losartan vs. valsartan: What are the differences?

Lisinopril, losartan, and valsartan are all medications used to treat high blood pressure. All three of these medications work to lower blood pressure by relaxing blood vessels. In addition to lowering blood pressure, these medications can also be used to treat different health conditions. Lisinopril and valsartan are approved to help reduce the risk of death after a heart attack, while losartan helps protect kidney function in diabetic individuals.

Lisinopril can increase the cough reflex, leading to a dry, hacking cough. The cough is typically not dangerous, but it can be bothersome enough that the person taking the medication will need to switch to a different blood pressure medication. Losartan and valsartan are much less likely to cause coughing. 

Finally, there are different reasons why a doctor may choose to prescribe one of these medications over the other. There is some evidence suggesting that losartan works for a longer period of time in the body, while valsartan has stronger blood pressure lowering effects and lisinopril may be more effective in reducing long term risk of heart complications. 

What are the long-term side effects of losartan?

Common side effects of losartan include dizziness, fainting, lightheadedness (especially when standing or sitting up quickly), and tiredness. A rare, but serious, side effect is swelling of the tongue, lips and eyes. This is called “angioedema” and it is potentially life-threatening. People who take losartan should seek medical attention immediately if this type of swelling occurs. Losartan should not cause hair loss and has minimal to no effect on weight management. When taken appropriately, losartan typically does not cause dangerously low blood pressures to occur. If you experience signs or symptoms of low blood pressure (including lightheadedness or fainting) while taking losartan, contact your doctor to discuss whether a change in the dosing of medication is needed.

Over time, losartan may cause the kidneys to keep too much potassium in the body or may reduce kidney function. Signs of these long-term side effects can include heart palpitations, shortness of breath, or changes in the quantity or appearance of urine. While taking losartan, your doctor should regularly monitor your electrolytes and kidney function.

Losartan interactions and contraindications: Can you drink alcohol while taking losartan?

Losartan does not typically cause serious interactions with other medications. Grapefruit juice consumption may have a small effect on losartan, but this is unlikely to cause any serious changes in blood pressure. Since both alcohol and caffeine can affect blood pressure, use caution when consuming these substances along with losartan.

Losartan warnings: why was losartan recalled?

In recent years, specific batches of losartan were recalled due to the detection of impurities in the losartan tablets. These impurities belong to a family of chemicals called nitrosamines. Nitrosamines are found in common household and food items, like hot dogs. The nitrosamines found in losartan included nitrosodiethylamine (NDEA) and N-methylnitrosobutyric acid (NMBA). These nitrosamines are associated with cancer development. The tablets made in the recalled losartan batches were found to contain unacceptable levels of nitrosamines, and because of this the manufacturer announced a voluntary recall to maintain safety standards. There were no reports of adverse effects linked to this recall.

Is losartan safe during pregnancy?

Because losartan use may cause harm during fetal development, losartan is not recommended during pregnancy. If you are pregnant and have high blood pressure, talk with your doctor to determine the safest medication regimen for you and your unborn baby.

What should you do if you accidentally took a double dose of losartan?

Taking an extra dose of losartan can lead to an abnormally low blood pressure. If someone develops unexplained or unexpected symptoms after taking losartan, or if too much was taken, use the webPOISONCONTROL® online tool to get help, or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.

References

Abd El-Hay SS, Elhenawee M, Maged K, Ibrahim AE. Cost-effective, green HPLC determination of losartan, valsartan and their nitrosodiethylamine impurity: application to pharmaceutical dosage forms. R Soc Open Sci. 2022;9(6):220250. Published 2022 Jun 1. doi:10.1098/rsos.220250 

American College of Obstetricians and Gynecologists' Committee on Practice Bulletins—Obstetrics. ACOG Practice Bulletin No. 203: Chronic Hypertension in Pregnancy. Obstet Gynecol. 2019;133(1):e26-e50. doi:10.1097/AOG.0000000000003020

Matchar DB, McCrory DC, Orlando LA, et al. Systematic review: comparative effectiveness of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers for treating essential hypertension. Ann Intern Med. 2008;148(1):16-29. doi:10.7326/0003-4819-148-1-200801010-00189

Overlack A. ACE inhibitor-induced cough and bronchospasm. Incidence, mechanisms and management. Drug Saf. 1996;15(1):72-78. doi:10.2165/00002018-199615010-00006

Brooke BS, Habashi JP, Judge DP, Patel N, Loeys B, Dietz HC 3rd. Angiotensin II blockade and aortic-root dilation in Marfan's syndrome. N Engl J Med. 2008;358(26):2787-2795. doi:10.1056/NEJMoa0706585

Kobori H, Mori H, Masaki T, Nishiyama A. Angiotensin II blockade and renal protection. Curr Pharm Des. 2013;19(17):3033-3042. doi:10.2174/1381612811319170009

Banerji A, Blumenthal KG, Lai KH, Zhou L. Epidemiology of ACE Inhibitor Angioedema Utilizing a Large Electronic Health Record. J Allergy Clin Immunol Pract. 2017;5(3):744-749. doi:10.1016/j.jaip.2017.02.018

Bezalel S, Mahlab-Guri K, Asher I, Werner B, Sthoeger ZM. Angiotensin-converting enzyme inhibitor-induced angioedema. Am J Med. 2015;128(2):120-125. doi:10.1016/j.amjmed.2014.07.011

Nakagami H, Morishita R. Obesity and gastrointestinal hormones-dual effect of angiotensin II receptor blockade and a partial agonist of PPAR-γ. Curr Vasc Pharmacol. 2011;9(2):162-166. doi:10.2174/157016111794519291

Brink M, Wellen J, Delafontaine P. Angiotensin II causes weight loss and decreases circulating insulin-like growth factor I in rats through a pressor-independent mechanism. J Clin Invest. 1996;97(11):2509-2516. doi:10.1172/JCI118698

Kataria V, Wang H, Wald JW, Phan YL. Lisinopril-Induced Alopecia: A Case Report. J Pharm Pract. 2017;30(5):562-566. doi:10.1177/0897190016652554

Steckelings UM, Artuc M, Wollschläger T, Wiehstutz S, Henz BM. Angiotensin-converting enzyme inhibitors as inducers of adverse cutaneous reactions. Acta Derm Venereol. 2001;81(5):321-325. doi:10.1080/000155501317140007

Sica DA, Gehr TW, Ghosh S. Clinical pharmacokinetics of losartan. Clin Pharmacokinet. 2005;44(8):797-814. doi:10.2165/00003088-200544080-00003

Related Articles

Back to blog
  • Getting up to speed on Adderall

    Adderall is a combination of 2 central nervous stimulants: amphetamine and dextroamphetamine. Its main use is the treatment of attention deficit hyperactivity disorder (ADHD). In overdose, it can cause serious central nervous system and cardiovascular effects.

    Find out more
  • fentanyl syringe

    What is fentanyl?

    Fentanyl is a powerful opioid pain medication as well as a common contaminant found in illicit drugs. It can cause users to stop breathing, resulting in death. The antidote naloxone (Narcan) can reverse the effects of a fentanyl overdose if given in time.

    Find out more
  • woman with heartburn holding a pill

    What is famotidine used for?

    Famotidine is a medication commonly used for heartburn, reflux, and other gastric conditions. The dosing of famotidine varies based on the condition being treated, and famotidine is usually taken once or twice daily. Side effects of famotidine include headache and constipation or diarrhea. Use of famotidine has not been associated with cancer development in humans.

    Find out more
  • women using freezing spray

    What is ethyl chloride spray?

    Ethyl chloride is a local anesthetic agent that relieves pain by cooling the skin surface. Ethyl chloride abuse, which occurs when individuals intentionally inhale its vapors, can result in sleepiness, abnormal heart rhythms, and death. Ethyl chloride is flammable and can cause frostbite if used incorrectly.

    Find out more
  • man taking medication

    What is Eliquis (apixaban)?

    Eliquis (apixaban) is an oral medication that reduces the risk of forming blood clots. The most common side effect is bleeding/bruising. Do not take more than prescribed as it puts you at higher risk for bleeding. Follow up with your healthcare provider regularly if you are prescribed this medication.

    Find out more
  • woman looking at acne on her face

    What is doxycycline?

    Doxycycline is a common broad-spectrum antibiotic prescribed for many kinds of infections. Therapeutic doses of doxycycline are generally safe, but doxycycline may cause severe reactions. It is important to understand what doxycycline is, be aware of precautions, and know what to do in instances of unintentional ingestion, overdose, or misuse.

    Find out more