Side Effects of Losartan Potassium: 7 Reactions to Be Aware Of

Taking losartan potassium could feel like a trade-off—you’re lowering your blood pressure but may end up with a few unwelcome surprises. You may notice dizziness kicking in whenever you stand too fast, or a dry cough that just won’t quit. Some people ache in their back or joints, while others see shifts in kidney function or potassium levels creeping up. And in case you’re pregnant, this med’s off-limits entirely. Curious about what else could catch you off guard?

Table of Contents

Dizziness and Low Blood Pressure

Taking your initial dose of losartan can feel like stepping onto a slow-moving boat—suddenly, the world tilts a little.

Dizziness is common as your body adjusts to lower blood pressure, especially in case you take diuretics. Orthostatic hypotension—lightheadedness when standing—can catch you off guard, so rise slowly.

Monitor your blood pressure regularly and report severe dizziness to your healthcare provider. They might adjust your dose or suggest lifestyle changes.

Stay hydrated and avoid sudden movements to ease side effects. Keep in mind, this usually improves as your body adapts, but don’t ignore persistent symptoms—your safety comes first.

Upper Respiratory Infections and Nasal Congestion

Since losartan helps manage blood pressure, you could notice your nose feeling stuffy or even catch a cold more often than usual.

Upper respiratory infections and nasal congestion are common among losartan users, though it’s unclear whether the medication or high blood pressure itself is the cause.

Here’s what you should know:

Symptoms: You may experience a runny nose, sneezing, or sinus pressure—similar to a mild cold.
Prevention: Stay updated on vaccinations to lower the risk of severe complications.
Avoidance: Skip oral decongestants—they can spike your blood pressure.
When to Act: Should symptoms linger, check with your healthcare provider.

Persistent Cough

While losartan is generally well-tolerated, some people notice a dry, nagging cough that just won’t quit.

Unlike ACE inhibitors, which often cause coughing, losartan usually doesn’t—but it can still happen.

Should you develop a persistent cough after starting losartan or switching from an ACE inhibitor, tell your healthcare team. They’ll check whether other health conditions or medications could be causing it.

Should the cough bother you, ask about management strategies, like sipping water or throat lozenges.

Should it linger, they may suggest alternatives to losartan.

Always keep them updated about changes in your health status to find the best solution.

Back and Joint Pain

Back and joint pain can sneak up on you as you take losartan, though it’s not as common as other side effects. While the exact cause isn’t always clear, mild discomfort can happen. Here’s what you should know:

Monitor your pain – When back pain or joint pain becomes severe or limits movement, tell your healthcare provider for better management strategies.
Avoid NSAIDs – Skip nonsteroidal anti-inflammatory drugs (like ibuprofen) for pain relief—they can raise your blood pressure.
Try gentler options – Over-the-counter creams or patches could assist without messing with your losartan.
Keep communication open – Regular check-ins with your healthcare provider guarantee your pain doesn’t disrupt treatment.

Should pain linger, don’t ignore it—adjustments could be needed.

Kidney Function Changes

Some people taking losartan might notice changes in how their kidneys work—these shifts can range from mild to serious, so it’s crucial to stay aware.

Losartan can affect kidney function, particularly in case you already have issues like type 2 diabetes or initial signs of kidney disease.

Watch for swelling, reduced urine output, or sudden weight gain, as these could signal acute kidney damage. Your healthcare provider will likely monitor creatinine levels through blood tests to catch problems promptly.

While losartan can slow the progression of kidney disease in some cases, staying alert and reporting changes helps keep you safe.

Regular check-ups make a difference.

High Potassium Levels

Since losartan works by relaxing blood vessels, it can sometimes cause your potassium levels to rise higher than normal—a condition called hyperkalemia. This isn’t common, but it’s serious enough to watch for. Here’s what one should know:

Symptoms of hyperkalemia include muscle weakness, fatigue, and gastrointestinal upset like nausea.
Monitor potassium levels regularly, especially in case you have kidney issues or take potassium supplements.
Irregular heart rhythms can occur in case levels get too high—don’t ignore palpitations.
Discontinue losartan temporarily in case needed, but only under your healthcare provider’s guidance.

Stay alert and report unusual symptoms right away.

Should you be pregnant or planning to be, you should avoid losartan because it can cause serious birth defects or harm your baby.

You need to talk to your doctor about safe alternatives and use effective birth control while taking this medication.

Should you find out you’re pregnant while on losartan, contact your healthcare provider right away to discuss next steps.

Birth Defects Warning

Because losartan potassium can seriously harm an unborn baby, the FDA has issued its strongest warning—a boxed warning—about using this medication during pregnancy. Fetal exposure to losartan could lead to severe birth defects, especially in the second and third trimesters.

Here’s what you need to know:

Birth defects: Losartan can cause skull deformities or kidney problems like renal dysfunction.
Oligohydramnios: Low amniotic fluid levels might occur, risking lung and limb development.
High risks: The medication isn’t safe at any pregnancy stage.
Talk to your healthcare provider: Discuss medication options in case you’re pregnant or planning to be.

Pregnancy Avoidance Guidelines

While losartan potassium effectively manages high blood pressure, it’s critical to understand the steps one should take to avoid pregnancy while on this medication.

Losartan can cause serious birth defects, so should you be of childbearing age, talk to your healthcare provider about pregnancy avoidance before starting treatment.

Consider reliable birth control and discuss alternative medications when planning a pregnancy.

Since losartan is unsafe during pregnancy, regular monitoring and open communication with your provider are key.

Should you accidentally become pregnant, contact them immediately to adjust your medication regimen.

Staying informed helps protect your health and any future pregnancies.

Fetal Harm Risks

Taking losartan potassium during pregnancy can lead to serious risks for the baby, including birth defects and complications. The FDA warns that losartan might cause fetal harm, especially in later trimesters. Should you be pregnant or planning to be, talk to your healthcare provider about safer alternatives. Here’s what you need to know:

Birth defects: Losartan can harm fetal development, like causing kidney or skull problems.
Low blood pressure: It could drop your baby’s blood pressure, risking organ damage.
Monitoring: Regular check-ups are essential should you be of childbearing age.
Alternatives: Safer options exist—ask your provider to switch meds early.