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Key takeaways
Olmesartan and losartan are both generic medications used to treat high blood pressure. They are angiotensin II receptor blockers (ARBs) that are taken once per day.
Olmesartan may be more effective at lowering blood pressure initially, but both drugs are considered effective for high blood pressure.
Both medications cause similar side effects and have a boxed warning about the risk of serious harm to an unborn baby. For this reason, olmesartan and losartan should not be taken during pregnancy. In rare cases, olmesartan can also cause sprue-like enteropathy, which causes severe, chronic diarrhea with significant weight loss.
Olmesartan and losartan are usually covered by insurance, and a SingleCare prescription discount card can lower the cash price of each drug.
Hypertension, or high blood pressure, occurs when the force of blood flowing through the blood vessels is too high. It’s a very common condition that affects nearly half of the adults in the U.S. However, many people don’t even know they have it. This is because hypertension usually doesn’t have obvious symptoms. But, untreated high blood pressure can increase your risk of serious heart conditions, such as heart attack and stroke. According to the American Heart Association, preventing and managing high blood pressure consists of healthy lifestyle changes and taking medications.
Olmesartan (Benicar) and losartan (Cozaar) are two generic medications approved to treat high blood pressure. They belong to a class of medications called angiotensin II receptor blockers (ARBs). They work by blocking an enzyme (protein) called angiotensin II, which narrows the blood vessels, causing the pressure inside the vessels to rise. This helps relax the blood vessels to lower your blood pressure. Although these medications work similarly, they have some important differences.
What are the main differences between olmesartan and losartan?
Olmesartan is a generic medication often referred to by its brand name, Benicar. It’s used to treat high blood pressure and is available as an oral tablet.
Losartan is also a generic medication. It’s available as a brand-name drug called Cozaar. Like olmesartan, losartan is approved to treat high blood pressure. Losartan also has additional indications. Similar to olmesartan, it comes in an oral tablet.
| Main differences of olmesartan versus losartan | ||
|---|---|---|
| Olmesartan | Losartan | |
| Drug class | Angiotensin II receptor blocker | Angiotensin II receptor blocker |
| Brand/generic status | Brand and generic available | Brand and generic available |
| What is the generic name?
Or What is the brand name? |
Benicar | Cozaar |
| What form(s) does the drug come in? | Oral tablet | Oral tablet |
| What is the standard dosage? | Adults: 20 mg once daily
Children: 10-20 mg once daily |
Adults: 50 mg once daily
Children: 0.7 mg per kg once daily |
| How long is the typical treatment? | Long term | Long term |
| Who typically uses the medication? | Adults and children ages 6 years and older | Adults and children ages 6 years and older |
Conditions treated by olmesartan and losartan
Both olmesartan and losartan are used to treat high blood pressure in adults and children ages 6 years and older. Losartan may also be prescribed to reduce the risk of stroke in people with high blood pressure and left ventricular hypertrophy (a condition in which the heart’s main pumping chamber is enlarged), and treat diabetic nephropathy in certain people with Type 2 diabetes and hypertension.
| Conditions treated by olmesartan and losartan | ||
|---|---|---|
| Condition | Olmesartan | Losartan |
| High blood pressure | Yes | Yes |
| Reduce the risk of stroke in some adults with hypertension and left ventricular hypertrophy | No | Yes |
| Diabetic nephropathy in some adults with Type 2 daibetes and hypertension | Off-label | Yes |
| Heart failure | Off-label | Off-label |
Is olmesartan or losartan more effective?
While losartan has been on the market longer than olmesartan, both drugs are effective treatment options for high blood pressure.
In a 2011 randomized controlled trial, researchers concluded olmesartan was more effective at lowering seated blood pressure than losartan. In a 2007 clinical trial, researchers found olmesartan and losartan were effective at decreasing seated diastolic blood pressure (SeDBP) after 4, 8, and 12 weeks of treatment. However, after 8 weeks, olmesartan lowered blood pressure more than losartan, and more participants reached a goal blood pressure of less than 140/90 mm Hg. After 12 weeks of treatment, both medications were equally effective at lowering blood pressure.
Nevertheless, the most effective medication can vary from person to person. A healthcare provider can help determine which drug will work best for you based on your medical condition, history, and other medications.
Coverage and cost comparison of olmesartan vs. losartan
In many cases, both medications may be covered by commercial insurance and Medicare Part D plans. But, the cost may vary depending on your plan’s drug formulary and the pharmacy location. Sometimes, a SingleCare prescription discount card can bring the cash price even lower. Without insurance, the average cash price for a 30-day supply of olmesartan is $202 for 30, 20 mg tablets. With a SingleCare coupon, this price can be reduced to $9 for 30, 20 mg tablets. Similarly, the average cash price of a 30-day supply of losartan is $76 for 30, 100 mg tablets. With a SingleCare coupon, you can pay a discounted price of $6 for 30, 100 mg tablets.
| Olmesartan vs. losartan costs | ||
|---|---|---|
| Olmesartan | Losartan | |
| Typically covered by insurance? | Yes | Yes |
| Typically covered by Medicare Part D? | Yes | Yes |
| Quantity | 30, 20 mg tablets | 30, 100 mg tablets |
| Typical Medicare copay | Varies | Varies |
| SingleCare cost | $9 | $6 |
Common side effects of olmesartan vs. losartan
Because olmesartan and losartan both belong to the same drug class, they share similar adverse effects. A common side effect of both medications is dizziness. Serious side effects of both medications include kidney problems and hyperkalemia (high blood potassium levels). They also both have a boxed warning about the risk of harm to an unborn fetus.
The following table shows some side effects of olmesartan and losartan. It’s important to note that this is only a partial list. For a comprehensive list of side effects, contact a healthcare professional.
| Side effects of olmesartan and losartan | ||||
|---|---|---|---|---|
| Olmesartan | Losartan | |||
| Side Effect | Applicable? | Frequency | Applicable? | Frequency |
| Dizziness | Yes | 3% | Yes | 3% |
| Upper respiratory tract infection | No | – | Yes | 8% |
| Nasal congestion | No | – | Yes | 2% |
| Back pain | No | – | Yes | 2% |
| Facial swelling | Yes | % not given | Yes | % not given |
| Nausea | No | – | Yes | % not given |
| Sleepiness | No | – | Yes | % not given |
| Headache | No | – | Yes | % not given |
| Tinnitus (ringing in the ears) | No | – | Yes | % not given |
| Shortness of breath | No | – | Yes | % not given |
| Abdominal pain | No | – | Yes | % not given |
| Swelling in the legs, ankles, and feet | No | – | Yes | % not given |
Source: Food and Drug Administration (olmesartan), Food and Drug Administration (losartan)
Drug interactions of olmesartan vs. losartan
Olmesartan and losartan can interact with similar drugs. Because both drugs can increase potassium levels, taking them with other drugs that raise potassium can increase the risk of side effects. Additionally, taking either drug with nonsteroidal anti-inflammatory drugs (NSAIDs) can make kidney problems more likely. It may also decrease the blood pressure-lowering effects of olmesartan and losartan.
Here are some of the most common drug interactions of olmesartan and losartan.
| Olmesartan vs. losartan interactions | |||
|---|---|---|---|
| Drug | Drug Class | Olmesartan | Losartan |
| Aldactone (spironolactone)
Inspra (eplerenone) Midamor (amiloride) |
Potassium-sparing diuretic | Yes | Yes |
| Zestril (lisinopril)
Vasotec (enalapril) Lotensin (benazepril) |
ACE inhibitor | Yes | Yes |
| Advil, Motrin (ibuprofen)
Naprosyn, Aleve (naproxen) Mobic (meloxicam) Indocin (indomethacin) Aspirin |
NSAID | Yes | Yes |
| Eskalith, Lithobid (lithium) | Mood stabilizer | Yes | Yes |
| Klor-Con, Micro-K (potassium chloride) | Potassium supplement | Yes | Yes |
| Prograf (tacrolimus)
Neoral, Sandimmune (cyclosporine) |
Calcineurin inhibitor | Yes | Yes |
| Heparin | Anticoagulant | Yes | Yes |
| Tekturna (aliskiren) | Direct renin inhibitor | Yes | Yes |
Warnings of olmesartan and losartan
Olmesartan and losartan have boxed warnings about the risk of serious harm to an unborn baby if taken during pregnancy, including death. Due to this risk, it’s not recommended to take olmesartan or losartan while pregnant. If you become pregnant while taking either of these drugs, stop taking the drug as soon as possible and contact your healthcare provider.
These medications can also increase blood potassium levels and cause kidney problems. These side effects may occur in anyone, but people who take certain drugs or have certain medical conditions may be at higher risk. Low blood pressure is another possible side effect of both medications. Due to this risk, it’s important to be aware of the symptoms of low blood pressure, such as dizziness, lightheadedness, and fainting. If these occur, consult your doctor right away.
In addition to the above warnings, olmesartan can cause a rare condition called sprue-like enteropathy, which causes severe, chronic diarrhea with substantial weight loss. This condition may occur within months to years after starting treatment. If you experience severe diarrhea while taking olmesartan, contact your healthcare professional right away. They may switch you to an alternative medication.
Frequently asked questions about olmesartan vs. losartan
What is olmesartan?
Olmesartan is a generic prescription drug used to treat hypertension (high blood pressure) in adults and children ages 6 years and older. Also referred to by its brand name Benicar, olmesartan is an angiotensin II receptor blocker (ARB) that comes as a once-daily oral tablet.
What is losartan?
Losartan, or Cozaar, is a generic prescription drug used to treat hypertension in adults and children ages 6 years and older. It’s also approved to reduce the risk of stroke in people with high blood pressure and left ventricular hypertrophy (a condition in which the heart’s main pumping chamber is enlarged) and treat diabetic nephropathy in certain people with Type 2 diabetes and hypertension. Similar to olmesartan, losartan is available as a once-daily oral tablet.
Are olmesartan and losartan the same?
No. While olmesartan and losartan work similarly and are both used to treat hypertension, they are different drugs. Losartan can be used for purposes other than high blood pressure, and each drug comes in different strengths. In addition, olmesartan can cause a rare condition called sprue-like enteropathy that causes severe, chronic diarrhea.
Is olmesartan or losartan better?
Olmesartan may be better at lowering blood pressure than losartan. However, both medications were shown to be equally effective after a few months of treatment. Both drugs are considered effective treatment options for hypertension, and your healthcare provider can help decide which drug will work best for you.
Can I use olmesartan or losartan while pregnant (if applicable)?
It’s not recommended to take olmesartan or losartan during pregnancy. In fact, both drugs have boxed warnings regarding the risk of serious harm to an unborn baby. If you are pregnant or planning to become pregnant, tell your healthcare provider before starting treatment with either of these drugs. They can recommend a safer medication for you.
Can I use olmesartan or losartan with alcohol (if applicable)?
Maybe. There aren’t any known interactions between alcohol and these drugs. However, alcohol, olmesartan, and losartan can cause similar side effects, including nausea, dizziness, and low blood pressure. Therefore, you may have a higher risk of these side effects if you consume alcohol while taking these drugs. Always consult a healthcare provider before you consume alcohol with your medications.
Does olmesartan cause weight gain?
No, weight gain wasn’t reported in studies of olmesartan. If you’re gaining weight while taking olmesartan, talk to your healthcare provider. They can help determine the cause.
What is the best drug to replace losartan?
It depends. There are several drugs that you can take as an alternative to losartan. These include other angiotensin-receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), diuretics, and beta-blockers. Each drug has different side effects, warnings, dosages, and drug interactions. Therefore, it’s best to consult a healthcare provider about which drug would be best for you.
Sources
- What is high blood pressure? American Heart Association (2024)
- Olmesartan, PubChem
- Losartan, StatPearls (2024)
- Losartan tablets prescribing information, Food and Drug Administration (2024)
- A randomized, double-blind, forced-titration study to compare olmesartan medoxomil versus losartan potassium in patients with stage 1 and 2 hypertension, Postgraduate Medicine (2011)
- Comparison of increasing doses of olmesartan medoxomil, losartan potassium, and valsartan in patients with essential hypertension, The Journal of Clinical Hypertension (2007)