blood pressure monitor, lower blood pressure

Losartan was introduced under the brand name Cozaar in 1995 for the treatment of high blood pressure. At the time, it was the first of a new category of blood pressure medicines now known as ARBs, or angiotensin II receptor blockers. Although they work on the renin-angiotensin enzymes just as ACE inhibitors do, ARBs have some distinct differences from ACE inhibitors like lisinopril. Losartan side effects are not the same as those found with lisinopril or other ACE inhibitors.

Losartan is prescribed for high blood pressure, alone or in combination with other drugs. It is often prescribed as a fixed combination with hydrochlorothiazide (HCTZ). Originally, this combination pill carried the brand name Hyzaar, but both losartan and the losartan-HCTZ combination pills have been available in generic versions for a number of years. It appears that losartan may be less effective for African-American patients than for others (American Journal of Hypertension, Nov., 2003).

Losartan Side Effects:

Some of the most common side effects that people on losartan have experienced include dizziness, nasal stuffiness, diarrhea, muscle cramps or pains including back pain, fatigue and indigestion. People with diabetes may experience episodes of low blood sugar.

Other Losartan Side Effects:

  • Low blood pressure
  • Chest pain
  • Nasal congestion, sinusitis, upper respiratory infection
  • High potassium levels
  • Angioedema (a reaction in which the throat or face may swell, possibly leading to a medical emergency)
  • Anaphylaxis (a life-threatening allergic reaction in which the person has difficulty breathing)
  • Fainting: this may be worsened by dehydration due to excessive sweating, diarrhea or vomiting
  • Kidney injury
  • Muscle breakdown
  • Fetal toxicity if the mother is taking losartan
  • Cough-less common than with ACE inhibitors, but persistent cough is occasionally a problem

Any symptoms should be reported to the doctor promptly.

Although dry eyes are not included in lists of losartan side effects, one reader reported severe dry eyes while taking this drug.

Use During Pregnancy:

Losartan, like other ARB medications, is not appropriate during the second or third trimesters of pregnancy. If a woman taking losartan becomes pregnant, she should consult her doctor as soon as possible. Nursing women should not take this drug without first discussing potential risks and benefits with their physician.

Interactions with Losartan:

Although losartan may be given in combination with many other types of blood pressure medicine, it should NOT be taken together with aliskiren (Tekturna) by people with diabetes or reduced renal function. This combination may lead to elevated potassium in the body (World Journal of Nephrology, Nov. 6, 2013). It could also put undue strain on the kidneys.

ARBs such as losartan work on the same enzyme system, generally, as the ACE (angiotensin-converting enzyme) inhibitors such as benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace) and trandolapril (Mavik). Combining losartan with any of these does not improve effectiveness, but it does increase the probability of side effects.

Because losartan can increase the amount of potassium circulating in the bloodstream, it can be dangerous in combination with potassium-sparing diuretics such as amiloride (Midamor), spironolactone (Aldactone) or triamterene (Dyrenium, or as a component of HCTZ/triamterene = Dyazide or Maxzide). Combining such medications could lead to elevated potassium levels. For the same reason, salt substitutes containing potassium chloride (NoSalt, Lite Salt, etc.) should not be used without medical supervision.

People taking lithium to treat bipolar disorder may need to have the dose adjusted. Taking losartan at the same time can raise blood levels of lithium and make side effects more likely.

Certain medicines may interact with losartan to lower blood pressure too much or unexpectedly. They include a number of drugs used to treat serious psychiatric disorders:

  • aripiprazole (Abilify)
  • aripiprazole lauroxil (Aristada)
  • asenapine (Saphris)
  • brexpiprazole (Rexulti)

There are also a number of antihypertensives that may lower blood pressure too much if they are taken with losartan. These combinations should be avoided or the dosage of one or both drugs may require adjustment. These include:

  • bendroflumethiazide
  • bumetanide
  • chlorothiazide
  • chlorthalidone
  • ethacrynic acid
  • furosemide
  • hydrochlorothiazide
  • indapamide
  • methyclothiazide
  • metolazone
  • torsemide

In addition, doctors need to be monitoring carefully if a person taking losartan is also taking an NSAID such as celecoxib, diclofenac, etodolac, ibuprofen, indomethacin, meloxicam, nabumetone, naproxen and others. These drugs may decrease the power of losartan to control blood pressure.

Losartan is metabolized by CYP enzymes in the liver (2C9 and 3A4). Despite this, it does not seem to have a significant interaction with grapefruit juice, which inhibits CYP3A4. Presumably that is because CYP 2C9 is more important for the metabolism of losartan.

The list of drug interactions here is not exhaustive, so be sure to check with your doctor and pharmacist to make sure that losartan is safe in combination with any other drugs you take.

Special Precautions:

People with liver disease may have trouble metabolizing losartan. The dose should be adjusted accordingly.

In people with severe congestive heart failure, losartan may put too much strain on the kidneys. The prescribing physician should be monitoring closely to make sure this is not happening.

Women should not take losartan if they are pregnant or nursing.

Taking Losartan:

Losartan may be taken when it is convenient, with or without food. It is taken once or twice a day, according to the prescription. The usual dose starts at 50 mg a day and may go to a maximum of 100 mg/day. People with reduced liver function and those taking a diuretic blood pressure medicine already are usually prescribed a lower dose of 25 mg daily to reduce the likelihood of losartan side effects.

Most recent revision: December 28, 2015

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  1. Sofia

    after 3 month of taking 25 mg i feel tireless headaches sometimes stomach Pain and nausea pain in my ears

  2. Marils

    My doctor put me on ARB medication Losartan for blood pressure, and told me I would get the full effect in about 6 weeks. A few weeks after starting Losartan, my feet started to feel achy. I did not associate the Losartan with the pain. Over the next month or so, the pain continued to increase, no matter what I did, or didn’t do. Being off my feet did not help. The pain was so bad I had trouble sleeping and could not even find relief in any position. Icing my feet only helped a little. I had to start using a walker in my home, and could only go short distances. Soon, not even a walker could help, as the pain was so great, I was unable put any weight on my feet. I was literally crawling on all 4’s or bedridden. Coincidentally, I talked with a relative of mine in Florida and told her what was going on. She said she started having foot and ankle pain and swelling after her doctor put her on something called Losartan. WHAT?!!! I called my doctor. First he was busy, then he was on vacation, then just plain old not returning calls — so I took myself off the medication and started looking for another doctor. The pain then slowly faded away. No more trouble walking. Some time later, another doctor started me on ARB medication Valsartan. The pain in my feet started to return. I am now off that too, and the pain is beginning to subside. None of the side affects I’ve seen listed have said how it can cripple you.

  3. Larraine

    Been having a terrible time with ear congestion soreness, weeping and itching of the ears and very little sleep maybe 2 hrs a night for a couple of years now. Been on losartin for about 3 years. Accidentally forgot to take my losartin last night. Got a good sleep last night and very little ear congestion. Thinking losartin is not a good drug to be on. IMHO. Will not be taking losartin again tonight and see what happens.

    • Aaron

      I’ve had the same problems with Losartan, Lisinopril, Propranolol, and Benedryl causing crippling symptoms, joint pain, hematuria and epididimytis, then discovered that symptoms disappeared when taken with a Claritin. The common denominator appeared to be titanium dioxide that is used as a preservative in the inactive ingredient or coating of tablets.

      Cut out the titanium dioxide and symptoms disappear. I’m looking to change my losartan to the oral form and have also started eating boiled eggs daily to decrease BP. So far it’s working and it appears that my body is allergic to titanium dioxide, a preservative that’s used in meds, foods, makeup, etc… if you continue this drug, at least take a Claritin to release antihistamine and reverse the reaction.

  4. bobbie

    I have these same feelings with this medicine. Dizzy and hard to breath.

    • Deb

      I was finally taken off losartan. Did nothing for my numbers but raise them, caused weight gain too, about 10 pounds. I was put on Tribenzor and it’s an amazing drug.

  5. bobbie
    Yuma, Az/

    I totally agree. This medicine has made me think I cant breath right and am so dizzy in the morning after taking it I must lay down. As the day goes on my body feels a little better, but still usually dizzy and tingly feellng.

  6. Judy
    United States

    I was laid from my job on Jan. 2016. I had an appointment to see my GP the next week. My BP was elevated so I told my GP about the the job loss and I believe this was the cause for my BP to me elevated he says it is quite possible. I was having sleep issues, anxiety and depression isssues as well. He prescribe 50mg for 90 days as well as an antidepressant for me to take. Since I have been relative healthy and was never on any meds I am not in a habit on taking on a regular basis. I took some when I remember in all was about 10 total. I took one antidepressant but again did not want to get hook on that as well. I started to feel cramping on the side of my stomach which I have not felt in years. I went back to the GP and he took my BP he did not tell me it was high but still prescribe 25 mg to take. He told me I have to take it for the rest of my life. I am 60 years old female I do not want to take this at all but my doctor thinks I have to. Now I do not know what to do if I should continue or stop.

    • Pharmacist Elizabeth
      Wisconsin, USA

      Medication therapy implies a ‘contract’ between you, your prescriber and health care team. You do NOT have to take any meds, but your actions affect the outcome of them. As an adult you agree to and carry out a particular med regimen. Failing to do this wastes time & money and leaves you with the risk having the condition go improperly treated.

      You cannot determine the outcome of a drug therapy without taking it either as prescribed or at least as you truthfully report to your ‘team’. Often dosages are altered because the expected affect of a med is not achieved. Sometimes this is because of a person’s faulty use of the med.

      If you have not told the prescriber HOW, WHEN and HOW MUCH of all meds you are taking, you are defeating the purpose of the med trial as well as putting yourself at risk from poorly treating the condition. The ‘off and on’ of your taking the med can worsen the condition as well as alter the outcome of other meds. Routinely taking the med is the only way to determine is efficacy.

      As far as forgetting to take doses, try to tie them to a routine activity like brushing your teeth or drinking your first cup of coffee of the day. When you start a new med or make any other change to alter your health KEEP A JOURNAL. Not a novel, just write down the date, doses (what, when, how much) and unusual events for the day (like you missed a dose at noon). To get the most from your appointments, write down your questions & health experiences prior to seeing the prescriber. You can also take another person with you to help assure your understanding of the interaction with your health care provider.

  7. Jaye

    I thought I was dying. I had been on Losartan for a year and could barely get out of bed. I blamed my symptoms on having fibromyalgia. I was scheduled for knee surgery, so the surgeon gave me a list of meds to stop taking two weeks prior to surgery. Losartan was on the list.

    After just a few days off of it, I noticed an increase in energy, the longer off of it, the more alive I felt. The cough that I was plagued with for over a year was completely gone. I was no longer short of breath, and felt much better.

    Needless to say, I never restarted that medication. It had been given to me because of one instance of slightly elevated blood pressure at the doctors office. I check my bp daily and have not had any more abnormals.

  8. Marion

    One day after my 65 birthday I felt I was having a heart attack. After about 3 years of using Losartan. I exuded once and for all to get off this drug. I changed my diet, drink few cups of organic green tea and exercise for at least 30 minutes each day. I feel so much better. ALL my awful unbearable symptoms are gone. Especially my muscle weakness. Thank God.

  9. Jackie

    Jackie UK

    I have been on Losartan for over 10 yrs! My BP was marginally raised due to losing my husband, working full time and bringing up two young children. I halved my dose to 25mgs because the tablets were scored and that seemed to keep my BP in check.
    I moved two years ago and was told that I should still take 50mgs by my new GP. I started getting a fuzzy head and tingling on my limbs.
    I was sent to see a neurologist who was very dismissive.
    I told myself to buck up as I was no longer working and eating well.
    My BP was checked in September and apparently it was 110/60 yet the GP I saw doubled my dose to 100 mgs !! I didn’t realise as I had been prescribed a different brand. This month I checked the box as I had felt so unwell. I had to go back to my GP and he put he back on 50 mgs. I should have been asked if I wanted the dose halved.
    I decided to just stop it last week. My BP has been fine and the symptoms have gone. I am never taking that crap again. I have also noticed I am no longer getting bad dreams or constant nasal drip.
    The symptoms were not in my head!!

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