losartan
Losartan, also known by the brand name Cozaar, is a first-choice medication that's used to lower blood pressure. It's also shown to protect against stroke in certain people. In addition, this medication can slow down the worsening of kidney problems in certain people with diabetes. Losartan (Cozaar) belongs to the drug class called angiotensin II receptor blockers (ARBs). This medication is taken by mouth once daily and is available as a lower-cost generic. Side effects can include dizziness, fatigue, and upper respiratory infections.
What is Losartan (Cozaar)?
What is Losartan (Cozaar) used for?
- High blood pressure
- Lower the risk of stroke in people with high blood pressure who have a thickened heart (left ventricular hypertrophy)
- Slow down the worsening of kidney problems in people with Type 2 diabetes and high blood pressure
How Losartan (Cozaar) works
Losartan (Cozaar) is an angiotensin II receptor blocker (ARB). The medication blocks a hormone that's normally made in your body called angiotensin II from attaching to its receptors (signaling proteins) in your body. As a result, this helps lower your blood pressure in a few ways:
- Relaxes your blood vessels so blood can flow through more easily
- Stops your body from releasing aldosterone, a hormone that normally causes your body to hold onto water and affect blood pressure
- Prevents your kidneys from absorbing water and salt (sodium) back into the body
Drug facts
Side effects of Losartan (Cozaar)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Upper respiratory infection (e.g., common cold; 8%)
- Dizziness (3%)
- Stuffy nose (2%)
- Back pain (2%)
Less Common Side Effects
- Tiredness or sleepiness
- Headache
- Stomach pain
- Swelling in the hands or feet
Losartan (Cozaar) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Dangerously low blood pressure: dizziness, lightheadedness, pale skin, feeling faint
- Serious kidney problems: urinating less often than usual; swelling in your feet, ankles, or hands; unexplained weight gain
- High blood potassium levels: nausea, muscle weakness, abnormal heartbeat
More on Losartan (Cozaar) side effects
The following Losartan (Cozaar) side effects have also been reported
Along with its needed effects, a medicine 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:
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
decreased urine output
difficulty swallowing
headache
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
Some side effects 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
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
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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Pros and cons of Losartan (Cozaar)
Pros
- A first-choice blood pressure medication, including for those with heart failure, diabetes, and kidney problems
- Taken once per day
- Can be taken by children as young as 6 years old
- Works similarly to angiotensin-converting enzyme (ACE) inhibitors, but with fewer side effects, like cough and swelling
Cons
- Might cause dizziness
- Might not work as well for Black people as other blood pressure medications do
- Not safe to use during pregnancy
- Can interact with medications like lithium and nonsteroidal anti-inflammatory drugs (NSAIDs)
Pharmacist tips for Losartan (Cozaar)
- Take losartan (Cozaar) exactly as prescribed. Don't change your dose or suddenly stop taking the medication without talking to your primary care provider or cardiologist first. Otherwise, your blood pressure might rise quickly. Ask your prescriber about the safest way to stop losartan (Cozaar).
- Measure and record your blood pressure at home and bring your log to your medical appointments. Your primary care provider or cardiologist can review your log with you, discuss how well the medication is working for you, and decide on any dose changes.
- You might feel dizzy when you first start taking losartan (Cozaar) and when your dose gets raised. This should get better over time as you continue taking the medication and as your body gets used to your new blood pressure.
- Make sure to tell your care team about all the medications you're taking before you start losartan (Cozaar). Also, don't start taking any new medications without talking to your care team first. Since losartan (Cozaar) can interact with other medications, it's best for your care team to check that all your medications are safe for you to take.
- Don't use nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil), while you're taking losartan (Cozaar) unless your primary care provider or pharmacist said it's safe to do so. Taking NSAIDs and losartan (Cozaar) together can raise your risk for kidney problems.
- Try to avoid eating foods that are high in potassium or using salt substitutes that contain potassium. Losartan (Cozaar) can raise your potassium levels and eating potassium-rich foods during treatment can put you at risk for dangerously high potassium levels. Contact your care team if you experience nausea, vomiting, or muscle weakness because these might be signs of high potassium levels.
- Follow a balanced and nutritious diet that's low in salt while you're taking losartan (Cozaar) to help lower your blood pressure. Depending on your risk factors and your other medical problems, it's possible that you might be able to stop taking losartan (Cozaar) if your blood pressure gets within goal.
- If you're pregnant or thinking of getting pregnant, contact your primary care provider or cardiologist right away. Losartan (Cozaar) isn't safe to take during pregnancy, so you'll need to switch to a medication that's safer for your baby.
More on Losartan (Cozaar) tips
Common questions about Losartan (Cozaar)
Losartan (Cozaar) typically starts to work within several hours. You'll probably notice that your blood pressure starts to drop within a week. But it can take several weeks to get the full blood pressure-lowering effect of the medication. Be sure to regularly measure your blood pressure at home and write them down in a log. Share your blood pressure numbers with your primary care provider or cardiologist at your follow-up appointments so they can get an idea about how well losartan (Cozaar) is working for you. Your primary care provider or cardiologist might adjust your dose and it'll take another few weeks to see the full effects of the new dose.
Across several clinical trials, the systolic blood pressure (the "top" number) dropped by an average of 13 mmHg and the diastolic blood pressure (the "bottom" number) dropped by an average of 10 mmHg in people who took between 50 mg and 100 mg of losartan (Cozaar) per day. Keep in mind that how much losartan (Cozaar) can lower blood pressure can depend on many things, such as your dose, any other blood pressure medications you're taking, and your medical conditions. It can also depend on your ethnicity; studies show that ARBs like losartan (Cozaar) work less well for Black people. Also note that everyone responds differently to losartan (Cozaar) and that it can take several weeks for the full effects of the medication to kick in. Talk to your primary care provider or cardiologist if you're concerned with how well losartan (Cozaar) is working for you.
There aren't any specific long-term side effects of losartan (Cozaar), but there are side effects that can happen at any time during treatment. Side effects, such as dizziness and fatigue, can happen as the medication works to lower your blood pressure. Additionally, losartan (Cozaar) can cause high potassium levels and potentially affect the kidneys. Although losartan (Cozaar) is FDA-approved to slow down the worsening of kidney problems in people who have diabetes and high blood pressure, research suggests that the medication might not be the best option for certain people who already have very serious kidney problems. Your primary care provider or cardiologist might order blood tests to check your potassium levels and kidney health during treatment.
Both losartan (Cozaar) and lisinopril (Zestril) are first-choice medications for lowering blood pressure, but they're not the same. They belong to different drug classes: losartan is an angiotensin II receptor blocker (ARB), whereas lisinopril is an angiotensin-converting enzyme (ACE) inhibitor. ARBs and ACE inhibitors affect the same system in your body to lower blood pressure, but in different ways. In addition, lisinopril is more likely to cause a dry cough than losartan (Cozaar). For this reason, people who get a bothersome cough from lisinopril can try switching to losartan (Cozaar). You can ask your primary care provider, cardiologist, or pharmacist to learn more about how the two medications compare to each other.
No, losartan (Cozaar) is not a beta blocker nor a diuretic (water pill); it's an angiotensin II receptor blocker (ARB). Beta blockers, diuretics, and ARBs are all medications that can help treat high blood pressure, but they work differently from each other. It's possible that your primary care provider or cardiologist might consider adding on a beta blocker or diuretic to losartan (Cozaar) in your treatment plan. This typically depends on factors like what other medical conditions you have and how high your blood pressure is.
Losartan (Cozaar) is typically taken just once per day. But the effects of the medication has also been studied when it's taken twice per day. Your primary care provider or cardiologist might split your daily dose into two and have you take the split dose twice per day if you have certain medical conditions or if you're older. This is because you might be more sensitive to the blood pressure-lowering effects of the medication. Talk with your care team if you have more questions about how to take losartan (Cozaar).
No, weight gain wasn't a side effect of losartan (Cozaar) that was reported during clinical trials. Speak with your primary care provider or cardiologist if you experience unusual or unexpected weight gain while you're taking losartan (Cozaar). They can try to help you figure out what's causing this weight gain.
No. People who took losartan (Cozaar) during clinical trials didn't report having a low heart rate as a side effect. Because of how the medication works, it's expected to only lower your blood pressure and not your heart rate.
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Risks and warnings for Losartan (Cozaar)
Losartan (Cozaar) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Harm to unborn baby
Don't take losartan (Cozaar) if you're pregnant because the medication can cause severe harm your unborn baby. This medication can affect how well the unborn baby's kidneys develop and work, which can be life-threatening.
Stop taking losartan (Cozaar) and let a member of your healthcare team know right away if you find out that you're pregnant during treatment. Discuss with your primary care provider or cardiologist about taking a different medication that's safer to treat your blood pressure if you're pregnant or thinking of becoming pregnant.
Low blood pressure
- Risk factors: Not enough fluid in your body | Having diarrhea or vomiting for a long time | Low salt levels in your body | Taking higher doses of diuretic mediations
Losartan (Cozaar) can cause your blood pressure to drop too much. This can make you feel dizzy, tired, or lightheaded. Having these symptoms of low blood pressure is more common when you first start losartan (Cozaar) or when your dose gets raised. You're also at risk if you're dehydrated or if you have medical conditions that cause you to become dehydrated, such as too much diarrhea or vomiting.
Make sure to stay well-hydrated. Be sure to sit down slowly while holding onto something if your blood pressure drops too much and you feel dizzy. Let your care team know if your blood pressure gets too low or if you feel dizzy, lightheaded, faint, tired, or confused while you're taking losartan (Cozaar). Get medical help right away if you fall and hit your head.
Kidney damage
- Risk factors: Severe heart failure | Kidney problems | Not enough fluid in your body | Taking other medications that can cause kidney damage
Although losartan (Cozaar) is sometimes used to protect the kidneys, it's also possible for the medication to affect your kidneys in a way that causes them to not work as well. This can happen to anyone. But the effects can be more serious in people with severe heart failure, people with certain kidney problems, or people who take medications that can worsen kidney function.
Your primary care provider or cardiologist might order lab tests every so often during treatment to make sure your kidneys are healthy and working properly. Your care team might recommend that you stop taking the medication if you develop kidney problems (or if your kidney problems worsen) while you're taking losartan (Cozaar). Let your primary care provider or cardiologist know if you're urinating less often than usual, as this could be a sign that your kidneys aren't working as well.
High potassium levels
- Risk factors: Taking other medications that can raise potassium levels
ARBs like losartan (Cozaar) can cause high potassium levels. Your risk is higher if you take losartan (Cozaar) with other medications that can raise potassium, such as spironolactone (Aldactone) or eplerenone (Inspra). Tell your healthcare team right away if you experience signs of high potassium levels, such as nausea, muscle weakness, or abnormal heartbeat. You'll probably need your potassium levels checked. If left untreated, high potassium levels can be dangerous.
Losartan (Cozaar) dosage
Tablet| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 25mg | 90 tablets | $12.92 | $0.14 |
| 100mg | 90 tablets | $12.93 | $0.14 |
| 50mg | 30 tablets | $7.30 | $0.24 |
Typical dosage for Losartan (Cozaar)
Your primary care provider or cardiologist will decide what your dose will be based on your age, the reason why you need losartan (Cozaar), your other medical conditions, and your other medications.
They'll adjust your dose based on how well you're responding to the medication and whether you're having side effects. Your dose might differ if you have liver problems and if you're taking diuretics (water pills).
- Ages 18 years and older: The typical dose starting dose is 50 mg by mouth once daily. The maximum recommended dose is 100 mg once daily.
- Ages 6 to under 18 years: The dose is based on your child's body weight. The typical starting dose is 0.7 mg/kg of body weight (up to 50 mg) by mouth once daily. The maximum dose is 1.4 mg/kg (up to 100 mg) once daily.
More on Losartan (Cozaar) dosage
Losartan (Cozaar) reviews
GoodRx has partnered with to provide reviews on the different aspects of Losartan (Cozaar).
Effectiveness
Learn more about the effectiveness of Losartan (Cozaar) based on real life experiences.
Overall Rating
Based on 143 people taking this medication
2
Effectiveness by condition:
high blood pressure (hypertension)128 reviews
3.7
Raynaud's disease8 reviews
0.2
chronic kidney disease3 reviews
4.2
IgA nephropathy2 reviews
1.9
multiple sclerosis2 reviews
0.0
Severity of side effects
Based on 238 people taking this medication
0%
50%
100%
Top side effects
Dizziness
5%
Dizziness with hypotension upon standing
2%
Cough
2%
Lightheadedness
1%
Diarrhea
1%
Reasons people stopped taking Losartan (Cozaar)
Based on 74 people who have taken this medication
Doctor's advice
44%
Other
21%
Side effects too severe
18%
Did not seem to work
11%
Course of treatment ended
6%
Change in health plan coverage
2%
Personal research
2%
How long people take Losartan (Cozaar)
Based on 612 people who have taken this medication
0%
50%
100%
Interactions between Losartan (Cozaar) and other drugs
More on Losartan (Cozaar) interactions
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Benazepril
- Captopril
- Ceritinib
- Clarithromycin
- Enalapril
- Enalaprilat
- Entacapone
- Fosinopril
- Lisinopril
- Lithium
- Moexipril
- Perindopril
- Potassium Phosphate
- Quinapril
- Ramipril
- Trandolapril
- Trimethoprim
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Bromfenac
- Bufexamac
- Celecoxib
- Choline Salicylate
- Clonixin
- Dexibuprofen
- Dexketoprofen
- Diclofenac
- Diflunisal
- Dipyrone
- Droxicam
- Etodolac
- Etofenamate
- Etoricoxib
- Felbinac
- Fenoprofen
- Fepradinol
- Feprazone
- Floctafenine
- Fluconazole
- Flufenamic Acid
- Flurbiprofen
- Ibuprofen
- Indomethacin
- Ketoprofen
- Ketorolac
- Lornoxicam
- Loxoprofen
- Lumiracoxib
- Meclofenamate
- Mefenamic Acid
- Meloxicam
- Morniflumate
- Nabumetone
- Naproxen
- Nepafenac
- Niflumic Acid
- Nimesulide
- Nimesulide Beta Cyclodextrin
- Oxaprozin
- Oxyphenbutazone
- Parecoxib
- Phenylbutazone
- Piketoprofen
- Piroxicam
- Proglumetacin
- Propionic Acid
- Propyphenazone
- Proquazone
- Rifampin
- Rofecoxib
- Salicylic Acid
- Salsalate
- Sodium Salicylate
- Sulindac
- Tenoxicam
- Tiaprofenic Acid
- Tolfenamic Acid
- Tolmetin
- Valdecoxib
How much does Losartan (Cozaar) cost?
Losartan (Cozaar) contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Losartan (Cozaar) will not be safe for you to take.
- Taking at the same time as aliskiren (Tekturna) in people with diabetes (high blood sugar)
What are alternatives to Losartan (Cozaar)?
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