Ibuprofen, Potassium Supplements, and More: 8 Losartan Interactions You Should Know About

If you have high blood pressure (hypertension), you’ve likely heard about, or might even be taking, losartan (Cozaar). After all, losartan is one of the most commonly prescribed blood pressure medications in the U.S. You might also be taking other medications, over-the-counter (OTC) products, and supplements with it. But is it safe to combine them?

Common over-the-counter (OTC) pain relievers, such as ibuprofen (Advil, Motrin), can interact with losartan. And potassium supplements can cause problems, too. Some losartan interactions can be avoided with safer alternatives. Others may need to be monitored closely. Let’s review a few possible losartan interactions you should know about.

Losartan interactions

The following medications, supplements, and foods can interact with losartan:

• Medications that raise potassium levels, such as spironolactone (Aldactone)

• Potassium supplements, such as potassium chloride (Klor-Con)

• Salt substitutes that contain potassium

• Lithium (Lithobid)

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin)

• Angiotensin-converting enzyme (ACE) inhibitors, such as lisinopril (Zestril, Qbrelis)

• Aliskiren (Tekturna)

• Entresto (sacubitril / valsartan)

This isn’t a complete list of possible interactions. So be sure to share a current medication list with your healthcare team before starting a new medication while taking losartan. Below, we’ll dig deeper into what you should know about eight common losartan interactions.

1. Medications that raise potassium levels

As a side effect, losartan can increase the amount of potassium in your body. Combining it with other medications that also have this side effect can cause your potassium levels to become too high (hyperkalemia).

Examples of medications that raise potassium levels include:

• Aldosterone antagonists, such as spironolactone and eplerenone (Inspra)

• Potassium-sparing diuretics (water pills), such as amiloride (Midamor) and triamterene (Dyrenium)

• Beta blockers, such as metoprolol (Lopressor, Toprol XL)

• Some immunosuppressants, such as tacrolimus (Prograf)

• Certain antibiotics, such as sulfamethoxazole / trimethoprim (Bactrim, Septra)

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If you need to take one of these medications with losartan, your prescriber should monitor your potassium levels. Be sure to keep all your lab appointments for blood work.

High potassium doesn’t usually cause symptoms. So you may not realize your potassium is too high without a blood test. But in severe cases, high potassium can cause abnormal heart rhythms. This can be life-threatening. Get medical help if you develop symptoms such as weakness, dizziness, or chest discomfort.

2. Potassium supplements

Because losartan can raise potassium levels, most people should avoid taking extra potassium with it. You generally shouldn’t take potassium supplements with losartan. This includes prescription options, such as potassium chloride and potassium citrate (Urocit-K). It also includes OTC supplements, such as potassium gluconate.

Some multivitamins also contain potassium. The amount of potassium in multivitamins is usually lower than in potassium supplements. But you should still ask your prescriber before taking them. Ask your pharmacist for help reading the OTC medicine label if you’re not sure whether your vitamin or supplement contains potassium.

3. Salt substitutes

Be on the lookout for salts and seasonings that are labeled as “sodium free” or “low sodium.” These salt substitutes can be alternatives to normal table salt. But they come with their own risks to keep in mind if you’re taking losartan.

Many salt substitutes swap the sodium found in regular salt for potassium instead. But this extra potassium interacts with losartan and can cause your potassium levels to become too high. It’s also difficult to keep track of how much extra potassium you’re getting since people use salt substitutes to adjust taste instead of by measuring certain amounts.

EXPERT PICKS: WHAT TO READ NEXT

• What to expect: Many losartan (Cozaar) interactions raise the risk of certain side effects, such as high potassium levels.

• Is there a best time to take losartan? Get pharmacist-backed tips for taking losartan, including whether or not you can take it twice a day.

• How it feels: Read firsthand accounts of how it feels to take losartan.

It’s best to avoid potassium-based salt substitutes if you’re taking losartan. Instead of those substitutes, you can build flavor with natural salt alternatives by using garlic, lemon, and paprika.

Good to know: You can usually still eat foods that are naturally rich in potassium while you’re taking losartan. Studies have shown that even eating high amounts of these foods doesn’t cause an interaction. But these studies didn’t include people with kidney problems. Talk with a healthcare professional about potassium-rich foods if you have kidney issues. They can determine if you should follow a kidney-friendly diet.

4. Lithium

Lithium is a medication used to treat bipolar disorder and other mental health conditions. It requires careful monitoring by a healthcare professional. That’s because too much lithium can cause side effects. And if your lithium levels get too low, it won’t work as well.

Your kidneys are primarily responsible for removing lithium from your body. Losartan can impact how your kidneys work. So the combination can lead to higher amounts of lithium staying in your body. This can result in a potentially life-threatening condition called lithium toxicity.

If you need to take losartan and lithium together, your healthcare team should monitor your lithium levels during treatment. If necessary, they can adjust your lithium dosage. Let them know if you develop the following:

• Confusion

• Blurry vision

• Muscle weakness

These could be symptoms of lithium toxicity.

5. NSAIDs

Losartan also interacts with NSAIDs, a popular group of pain relievers. Many are available both OTC and as a prescription medication.

Common NSAIDs include:

• Ibuprofen

• Naproxen (Aleve, Naprosyn)

• Meloxicam

• Celecoxib (Celebrex, Elyxyb)

NSAIDs carry a risk of kidney damage, especially for older adults and for people with kidney disease. Losartan can help protect the kidneys, but it can also affect kidney function in some people.

Combining NSAIDs with losartan can increase the risk of kidney problems. This is especially the case if you’re older, taking water pills, or have kidney disease.

What’s more, NSAIDs such as ibuprofen can raise blood pressure. So, your blood pressure may not be as well-managed while taking losartan. Because of this, some healthcare professionals may recommend avoiding NSAIDs if you have high blood pressure.

Talk to your pharmacist or prescriber about which pain relievers are safe for you. They can suggest safer alternatives that may be more compatible with losartan.

6. ACE inhibitors

You shouldn’t take an ACE inhibitor if you’re taking losartan. ACE inhibitors are another first-choice medication for high blood pressure. Examples include:

• Lisinopril

• Enalapril (Vasotec)

• Benazepril (Lotensin)

• Quinapril

• Ramipril

• Captopril

• Fosinopril

Losartan, on the other hand, is an angiotensin II receptor blocker (ARB). ACE inhibitors work in a similar way to ARBs. You’re typically prescribed one or the other — not both. That’s because combining them can cause more side effects without additional benefits. This includes serious side effects, such as low blood pressure and kidney failure. Because of these risks, your prescriber will typically avoid this combination.

7. Aliskiren

You shouldn’t combine losartan with aliskiren, another blood pressure medication. Aliskiren also works similarly to ACE inhibitors and ARBs. As with the interaction above, taking losartan and aliskiren together can cause more side effects without added benefits.

It’s recommended to avoid this combination. This is especially the case if you also have diabetes or kidney disease. These conditions raise your risk of complications with this losartan interaction.

8. Entresto

You should also avoid combining losartan and Entresto, a heart failure medication. Entresto is a combination pill that contains an ARB called valsartan. Since valsartan and losartan are both ARBs, it’s not recommended to take them together.

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Written by:

Timothy Aungst, PharmD

Timothy Aungst, PharmD, has worked in pharmacy practice for a decade. He has served as an associate professor of pharmacy practice, a clinical pharmacist in outpatient cardiology management, and now in home healthcare.

Written by:

Tegan Smedley, PharmD, APh

Tegan Smedley, PharmD, APh, has 10 years of experience as a pharmacist. She has worked in a variety of settings, including retail, hospital, and ambulatory care.

Reviewed by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

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