Cozaar is the first of a new kind of blood pressure medicine, anangiotensin II blocker.

Cozaar is prescribed for high blood pressure, alone or in combination with other drugs. It appears to be less effective for African-American patients.

Side Effects and Interactions

People on Cozaar have experienced dizziness, insomnia, muscle cramps or pains, nasal congestion and sinusitis.

Other side effects reported include faintness, low blood pressure, diarrhea, indigestion, and chest pain.

Dizziness or faintness may be worse if a person becomes dehydrated through excess sweating, diarrhea or vomiting. Report any symptoms to the physician promptly.

Cozaar is not appropriate during the second or third trimesters of pregnancy. If a woman taking Cozaar 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.

Tagamet may increase the level of Cozaar slightly, while phenobarbital reduces it. Interactions with other drugs such as erythromycin, Nizoral, or Sporanox have not been documented but are theoretically possible.

Cozaar is metabolized by CYP enzymes in the liver. As doctors gain more experience prescribing this medicine, more interactions may come to light. Check with your doctor and pharmacist to make sure Cozaar is safe in combination with any other drugs you take.

Special Precautions

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

Taking the Medicine

Cozaar may be taken when convenient, with or without food. It is taken once or twice a day, according to the prescription.

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  1. randy

    Hi. I was put on Bystolic for blood pressure in June. two months into taking the medication I had such severe side effects. I had constant muscle spasms, muscle aches and pain that would come and go through my body, I could not focus, I had a burning sensation in my face with tingling through my body. It caused me to get depressed and develop bad anxiety. I weaned myself from 10mg to 2.5 mg and went to the doctor and told him and he switched me to 50mg Losartan. He switched it in August and then the doctor place me on Losartan. I felt good for the first few weeks. Almost 2 and a half months in and I am getting severe body aches that come and go, my anxiety is back and worse, severe sinus congestions and ear ringing and a congestion. So, as of Wednesday the doctor took me off this medication but the side effects seem to have gotten a little worse. How long will it take to get back to feeling normal and for these side effects to stop? Before ever starting medications last June I never had and ache or pain or felt bad at all.

  2. loletha

    Im taking 25mg of Losartan potassium and so far so good. I’m experiencing a lack of saliva and dry throat and sinus, like the roof of my mouth. I take children antihistamines 1tsp and that helps with side affects. I take vitamins and minerals, also and Cardizem 60mg at night, but i don’t think I
    need that much, my bp jas come down from 149-160/91-101, it’s now 133/84-124/81-86 I physically feel better and i don’t frequently urinate but i have soft stools. But i drink hibiscus and lemon herbal tea alongside Mother earth apple sider vinegar.

  3. Faye
    Buffalo, NY

    Was it ever answered how long it stays in your system? I would like to know as soon as possible. I was having all the symptoms mention in this article..Except I am falling all over the place and I even have fractured a rib. My Drs told me to stop taking the drug, Which I have on Friday Sept 25 2015.. I would appreciate any assistance you can give me.. Thank you

  4. Eugene J.
    Stockton , California

    I have had EVERY single symptom or side effect on here… EVERY ONE… I stopped taking last week and I feel a lot better… it was affecting my driving, I felt sick all the time and dizzy almost fainting.. that stuff is no good.. I’m going to ask my doctor for a lighter alternative… does anyone know how long it takes to get out of your system?

  5. Tamera

    began losartan 25 mg suffered terrible jaw pain anyone else do this also

  6. Ginger
    Cape Coral FL

    I am so glad I found this site now I know why my migraines have come back. I haven’t had one in years and all of a sudden they came back and I get so weak. Does anyone know how long it takes to get out of your system? I have never felt so bad in all my life just started the leg cramps two months is all I have taken them no more for me

  7. nancy m

    My husband takes Losartan. It was prescribed in November. Over the past 5 months he has lost 20 pounds and has stomach cramps daily that require him to lay down and rest. Has any one experienced this.

  8. Joanna M

    Has anyone else experienced peripheral neuropathy while on Losartan? I want to wean myself off this drug – blood pressure permitting – to see if it’s possibly the cause of my neuropathy, before spending tons of time/money on trying to determine another cause. How long before the drug is completely out of your system?

    • Andy

      Yes, yes and more yes. Felt horrible over the last year. Brain fog, eyes killing me. Random headaches, electric-like nerve feelings all over. Brain Legs and feet killing me. No energy or emotion at all. Just in pain and Zombie-like. I quit taking Losartan yesterday. Leg pain and nerve tingling gone in a day. I just have a lingering headache, which is just a mere annoyance compared with the other symptoms. Losartan may work for some folks, but it tried to kill me.

      • The People's Pharmacy

        Be sure to get in touch with your health care provider and explain what you have done and why. It may not be safe just to quit, so you should be prepared to consider additional options.

      • Eugene J.

        I felt the same way… I stopped taking it like a week ago… I still have a light headache.

  9. V Vu
    San Jose, CA

    My mother was put on Losartan for the past month and started developing severe peripheral neuropathy in her hands and legs. She also started experiencing severe diarrhea, headaches, joint pain, lethargy, mental fog, insomnia, and other reactions. She was an active and healthy 83 year old woman up until that point. Now she could barely walk or even feed herself. We took her to an orthopedic doctor and physical therapist, and they could not find anything wrong with her. Then I realized that all of this began after taking Losartan. I felt awful because I urged her to take it because “the doctor said so.” I took her off of it, and two weeks later, there is still no improvement. The doctor who prescribed it doesn’t think it is losartan that is causing the neuropathy and told us to her to an orthopedic doctor or physical therapist, which we’ve already done. This is crazy!

  10. Rhianna
    Hamilton, Ohio

    Hi, I have been reading posts on Losartan and have been finding them extremely helpful. About two weeks after being put on it, I started getting rapid muscle twitching by my left knee. The twitching got so bad that I had to go to ER because I was also having a stabbing pain (from the muscle getting tired). They gave me a shot for pain at the ER and told me I was a little low on Potassium and gave me a muscle relaxer/pain spasm medication which has done nothing for the twitching. I asked if the twitching would go away or if I would have it forever, and they would not answer me.

    At that time, I also started on Buspar (anti-anxiety medication) and in Late January Topamax (Mood Stabilizer/Emotion regulation). At first, I read up on the side effects of Topamax and Buspar and unfortunately, some of the side effects mentioned were muscle spasms/twitching. The Psychiatrist assured me that neither Buspar and Topamax cause Tardive Dyskinesia or muscle twitching and said they are both excellent medications with few side effects. I then spoke to my General Practice Doctor about Losartan causing muscle twitching and he said I was on too low of a dose to have cause that.

    I am getting a second opinion. What is wrong with these doctors? Why won’t they listen? My concern when reading posts is people are saying go “natural”. No such thing. If you are on any chemical medications such as antidepressants or other drugs and taking herbal medications/supplements this can be very dangerous, and before doing this..always…always..check with your doctor first, before taking any supplement or herbs. Anything “natural” has to be synthesized which has a chemical reaction. No one knows where these products are made..Timbuktu…China, no one knows how much you are actually getting on these “natural” remedies and it could be fake/black market and cause serious side effects and be dangerous in the long run. Be careful with mixing any kind of supplements with prescribed medications. Supplements and herbs are not regulated by the FDA and many herbs have been taken off the market due to fatal interactions or just bad stuff by greedy people promising snake oil cures. Just be very careful.

  11. terence
    White Rock, BC Canada

    Whoa! I am having every symptom listed on here! They are all being treated as individual ailments.
    Eyes highly irritated with severe vision impairment – allergy & lubrication drops
    Lower back pain – time-released narcotic
    Ankle/lower leg rash – cortisone ointment
    Tingling hands – nothing
    Fatigue – wellbutrin
    Neck/upper shoulder pain – physiotherapy
    Cold feet, lower legs – wear long woolen underwear
    Cold hands – Raynaud’s suggested
    TIA (mini-stroke) – statin added to BP meds
    GERD – Rabeprazole

    Taking Cozaar, Clonidine, a statin,

    Anyone suffering with Gastro intestinal reflux disease on Cozaar/Losartan?

    All these symptoms began when I started taking the above – and nothing else. So this has to be the cause, wouldn’t you say? I am sooo grateful to have found this valuable resource online!

  12. Krista

    I recently had a bad flare up of raynauds. My doctor placed me on lossartan potassium 50mg once per day to try and open the capillaries in my feet. I have always had excellent blood pressure. After a few days on these Meds I experienced headache, dizziness, “foggy thinking,” fatigue and severe ringing in my ears. I have to get up very slowly or I get faint. I can’t do more then a walk on my treadmill where before I was running 30 min every day.

    Called my dr. He wanted me to stay on these meds. He said he doesn’t know why I’m experiencing these symptoms. After doing some research I figured these were side effects of the losartan. I saw a specialist yesterday. She immediately took me off the lossartan. Hoping to feel better soon. Does anyone know how long it takes for the side effects to go away? I’m tired of not being able to function very well.

    • Deb

      I’m not surprised your dr wants you to stay on losartan! Why are they so hard headed? I’ve been on losartan 100/25 since December 2014. and my body aches everywhere. I can’t do my exercise class because I ache so much. I know it’s the losartan causing this. I’m an active 61 year old grandmother and as of now I feel 91. It doesn’t do the greatest job at regulating my blood pressure either. I also have stomach cramps, diarhrea, dry mouth, anxiety to the point my dentist will not do a procedure because my blood pressure is elevated, I’m extremely fatigued. I have a dr appt, coming up and will be expecting another course of action be side this is horrible way to live

      • Ellie

        I was given these a few years ago,Took for few days then stopped as i felt they where making me feel ill.Now year on i thought i should try them again and 2 days i could hardly do anything,I was in so much pain my hands,feet ,knees, back,I decided thats enough no more,I stopped taking them and 3 days later i was back to my old self, 62 years old and the losartan potassium made me feel 90.I dont trust Doctors to be honest.We must take control of our own life dont always rely on Docs.

    • Thea

      I want to thank all of you for your comments about the side effects you experienced when you took Losartan. I went to my Dr. yesterday and my BP was slightly higher than it had been. I went because my legs and ankles were swelling. The only thing that I had changed was my inhaler and I stopped using sea salt. But because my BP was slightly higher, he gave a prescription for Losartan Potassium and Furosemide.

      I always look up prescriptions for me and my husband for posible side effects. I was concerned also about the dosage that he wanted me to start, which was 100mg. a day. I thought that this was a bit excessive to begin with and then in my research I found out that this medication may not work with African Americans (which I am). Also, looking at the side effects and reading all of your comments, I realize that it may cause headaches. I have suffered from migraines for years and the thought of taking something that may make them worse is insane to me.

      I am also a 63 year old grandmother and I don’t want to wind up with muscle cramps etc. So, thank you all again for your comments. I am going to show my findings and your comments to my doctor and find some other natural way to bring down my BP and stop the swelling.

      • Deborah
        Houston, Tx

        The medical printout for losartin says this medication may not work with African Americans. I read this in black and white. Why doesn’t the dr know about this?

  13. Jean

    I was on Losartan Potassium for over five years. During this time I increasingly had leg, back and hip pain that I (and my doctor) attributed to getting older (I’m 52). I finally decided to stop taking it about two weeks ago. It took about four days for the pains to stop, I started feeling so much better, more energetic and less tired. Now three weeks later, I am pain free and NEVER taking that crap again. What a waste of my time and toll it took on my body. I must’ve taken Motrin every day thinking I needed it for old age pain.

    • Deb

      How was your blood pressure after you stopped the Losartan?

  14. Eileen

    I have always tended to have somewhat low blood pressure but after being diagnosed with Breast cancer my BP increased significantly and my doctor put me on 50mg Losartan. In September I had developed a serious enough cough that it was diagnosed as bronchitis and I was put on 3 courses of prednisone and a couple of different antibiotics. When these did absolutely nothing I was sent to a pulmonologist who did a chest CT scan, pulmonary function test, sinus ct scan and a bronchoscopy with no results. I was diagnosed as having postnasal drip and put on Flonase, Zyrtec saline spray and a cough suppressant.

    By the 2nd week of January I had no improvement. I had developed severe headache probably from coughing so much and experienced gagging and most days vomiting of the excessive mucus my body was producing. I also back in November had started having stress incontinence from the violent coughing. All around pretty miserable.

    I was sent to an ENT doctor who examined by nose and throat and found nothing. He determined that I was experiencing a bad reaction to Losartan. I am tired all the time and now am back on steroids because my larynx is so swollen from coughing. I’ve been told it will take about a week before the symptoms will go away and remain hopeful that this nightmare will finally end.

  15. Cynthia
    Key West

    Never had a issue with HBP. In 2009 I had a severe cold and treated myself with over the counter cold meds. While at work I suffered a mini stroke (TIA) and was hospitalized with a blood pressure reading of 231/128. I was immediately put on Lopressor. A few years later I was changed to Losartan 50 mg. Since the very start I noticed severe muscle aches, crippling hand and feet spasms. Edema in both ankles and calves. I did not consider it was side effects from this drug until recently when I have taken a keen interest in the logistics of generic drugs. Today I am weaning myself off which I have been forewarned is a major No-No. I want quality in my life. I am 66 years old.

  16. kimberly p.

    been taking diovan for several months now, insurance wont pay for it anymore, so being switched to losartan, I am worried after reading all of these comments.

  17. Lee J.
    Lagrange Georgia

    I was put on Losartan potassium after two of my labs came back with very low potassium but after a month or so I have a tremendous about of muscle spasms/cramps. It’s been over a year now. I tell my doctor but he seems to not be concerned. He claims its my job is causing my muscle problems and very well could be but I have a potassium deficiency seems like that could be the reason my muscles cramp and hurt so much. It’s very interesting that so many people are on Losartan and having major muscle pain.

    • Ron

      I was on Losartan-HCTZ 50-12.5mg and my doctor told me that it causes low potassium. So she prescribed me a potassium supplement. I still have the leg cramps so I’m looking to switch from Losartan. I’m sure there is something else better available.

      • The People's Pharmacy

        Losartan/HCTZ can cause high potassium, not low: “Hyperkalemia, hyponatremia have been reported with losartan.” From dailymed

  18. steve

    Was put on 50mg to start with for secondary hypertension. Felt the side effect immediately (strange feeling in my head, not dizzy or light headed, but more like a fuzzy feeling) and asked for a new medication. I’ve been on lisinopril, amlodipine, labetalol, propranolol, spironolactone (was in combination with a BP med) and they never had side effects (was switched off for other causes).

    Losarton is by far the first medication I have ever taken and if this was my only option I’d rather not take anything.

  19. Stephany

    They gave me Losartan about 4 years ago, side effects were awful. I thought maybe it was just me so I tried it again. Insurance would no longer pay for Cozaar so the Pharmacist suggested I try Losartan again. This time I ended up in the ER with a massive headache, BP was high and the Doctor thought I was having a stroke, fortunately I was not having one, it was from the Pill. Then my Doctor put me on Benicar, I have had no side effects with that. But Insurance does not want to pay for it and again it wants me to take Losartan again and I refused. I guess at this point I am between a rock and a hard place. Any suggestions would be appreciated!

    • JT

      There are wonderful integrative physicians out there that treat alternatively first before they ever consider the pharmaceutical route. Please consider seeing one or a naturopath, DO, who can treat you holistically hopefully without meds. It is well-worth doing.

    • Rand
      United States

      Benicar nearly killed me and I had all of the side effects that were on the insert. It could shut down your kidneys and cause renal failure. It’s so bad!!!!!

  20. Bettye C.
    Laguna Niguel CA

    I think I have posted before but in any case new developments. Losartan 100mg since March 2014 and Clonidine 0.1 mg at night. Hypertensive crisis out of the blue that landed me in ER x3 early part of the year. Spiking continued at night, thus the Clonidine which keeps it at bay. However, the blood work at the start of the year gave me an almost normal Cholesterol and Triglycerides. 9 mos later with all the drugs on board, the Cholesterol and Triglycerides increased enough to warrant a call from the Doctor. My diet is sterling and he agrees so. I found online the Framington study that revealed Losartan Potassium ( not the one with thiazides) increases cholesterol and triglycerides. I showed my Dr the paper and he was shocked. He is studying this. I would never grant an allowance to take statins and my Dr knows this and he did not push it. Cholesterol is paramount to develop stress hormones and neurotransmitter health and a million other critical things in our body. To lower it, brings on depression. Big pharma has profited from lowering cholesterol and guess what? it is only a symptom of poor exchange at the cell membrane and not the cause of atherosclerosis.

    My Dr. understands my body and has managed my meds to my satisfaction now and always points a finger in the direction of alternative help with meditation etc anything that can give a peace of mind. That he says, is primary to anyone and more importantly one with High BP and additionally one with menopause and depleted hormones. I have a huge huge sensitivity to drugs and he also carefully watches me. One of the last great family guys who knows his stuff and thinks outside the box as well. We are all individuals that react to disease processes and drugs so differently as is evident even here on this forum.

  21. Jane K.
    United States

    My doctor put me on losarten without much explanation. I already suffered from dry mouth from other medicines. The lower palate of my mouth became so sore with ulcers I could hardly stand it. I was even made to have a biopsy which was negative…I stopped the losarten and it cleared up on it’s own.. ????

  22. dee

    I have been taking losartan for six months. The muscle pain started gradually. I am now in so much pain that I can not walk without crutches. After reading about others reactions to losartan I can relate. Dry mouth vision change no sleep nightmares dizziness and confusion. Went back to the Dr. with complaints, she said I need more exercise and no pain no gain. I am appalled that Dr. would prescribe this med when side effects are so bad. I will end up in a wheelchair or worse if I continue this med. I think there should be a class action suit and then maybe doctors will be more careful with what they prescribe.

    • Bettye C.

      I am grateful that my husband is a holistic chiropractor and advanced nutritional response testing practitioner. Try and find one in your area and be tested. There are ways to help your muscle pain by covering the meds major side effects with products that are natural and then targeting the cause of the pain. There is a way. Have faith.

      We treat so many patients on these awful meds and they do so much better without decreasing them which we do not interfere with. Minerals deficient suddenly can be remedied. There are advanced compounds via decades old true blue supplements. But muscle testing with an advanced practitioner is key. Good luck.

    • Shelley

      I took Losartan for several months and have intense muscle pain. The doctor believes it’s an adverse side effect from the medicine. I have been off the medicine for two weeks now but I’m not seeing much improvement. It’s very painful to walk. Was wondering if your symptoms have improved or if you know if how long the side effects may last, or what if any remedy is there?

    • Sunny
      United Kingdom

      Hi Dee and all on Losartan. I have written previously on the horrible side effects. The lastest one being problems with my vision. About a month ago, while watching telly, I suddenly noticed that I had developed floaters in both eyes and that the left eye was every now and then giving me double visions.

      Iaw an ophthalmologist and he said I had dry eyes, which is so true and at times when I wake up in the mornings, my eyelids are stuck fast to the eye and I have to prise them open which does hurt. I have also been suffering from horrible flushes from head to nape area and sinus problems which give me terrible headaches and my cheekbones actually ache.

      Doctors I have consulted are only interested in changing the meds. By the way I have been on enalapril, then losartan and now cozaar SQ which is 50mg losartan and 5 mg amlodipine. Today, I just stopped taking it. I am going to try another doctor. Anyone has any suggestions ? Would really appreciate. By the way when doc put me on med because BP was at prehypertensive level. I do regret giving in to the doc’s persuasion to start it in the first place

  23. Pat W.

    Bummer! Now I’m worried. I’ve been on Benicar for 3-4 years now, with no problems or side-effects, but my new insurance doesn’t cover it, and just this past Monday my doctor switched me to Losartan 50mg. Pills arrived by mail today, and in searching the web, found this review of Losartan and I’m worried about even starting on this new to me medication.

  24. mary k

    As I read these comments it brings back horrible memories for me as I had a miserable time on these blood pressure medications. I am 82 and was put on these meds two years ago. A horrible two years for me. I found a natural way to be able to get off these meds and now my blood pressure is NORMAL with no pills. It can be done. Find a doctor for integrative medicine. There is one in Encinitas, California. Don’t just keep taking all of that stuff.

  25. mary k

    I would talk to your doctor about getting off the drugs. I was on both for a while and I felt as though I had been poisoned. Go to a naturopath doctor and get some natural help for HBP. Also, check to see if you might have sleep apnea as that causes HBP. It did for me. Now my BP is normal and I feel great and I no longer take any pharmaceuticals.

  26. TSK

    I have been on Losartan Pot 50mg since January. Since then, I really don’t feel like I’m sleeping but just dozing. At night, the muscle cramps in my legs are SO BAD that they are constantly waking me up. Also, have gained 10 pounds (no diet or other changes), I had maintained for over ten years a consistent weight. Has anyone else experienced these problems… I will definitely be looking to go back to Benzapril.

  27. ms

    My doctor has me on 50mg losartan potassium 2X daily. After my a.m. dose at about 6:00 I feel pretty good. However about 1:00p.m. I start getting anxious and get the ringing ear effect. I don’t want to take my p.m. dose until about 7:00 so that it will stay in my system thru the night. I also take 10mg buspar just before going to bed and sleep good. Hopefully these afternoon effects will gradually go away?? I have been on this 1 month.

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