Does losartan cause insomnia?

In this article:

• Why is losartan prescribed?
• Does losartan cause insomnia?
• Why might losartan or Cozaar affect sleep?
• Common losartan side effects
• Tips for better sleep while taking losartan
• When to see your healthcare provider

In this article

• Why is losartan prescribed?
• Does losartan cause insomnia?
• Why might losartan or Cozaar affect sleep?
• Common losartan side effects
• Tips for better sleep while taking losartan
• When to see your healthcare provider

Most people taking prescription medications are hoping to improve or resolve symptoms of a particular health condition, not create new ones—but unfortunately, most prescription drugs come with a set of side effects, or adverse drug reactions, that can add to the list of reasons why you’re feeling unwell. One common adverse drug reaction is changes to your sleep habits, and people taking the popular blood pressure medication losartan, the generic form of Cozaar, may experience this firsthand. Although insomnia isn’t considered a common side effect of losartan, it has been reported in clinical trials alongside other nervous system symptoms like drowsiness and headache. Here’s why losartan could be disrupting your sleep, plus how to manage it and when to contact your provider. 

Why is losartan prescribed?

Losartan is a prescription medication typically used to treat high blood pressure, or hypertension. It is also sold under the brand name Cozaar. Losartan is part of a class of drugs called angiotensin receptor blockers (ARBs), which work by relaxing the blood vessels to allow blood to flow more freely. Losartan can also be used to treat diabetic nephropathy and heart failure, and to prevent stroke in certain high-risk populations.

Does losartan cause insomnia?

For some people, taking losartan affects their sleep patterns and causes insomnia, making it harder to fall asleep, stay asleep, or get enough hours of sleep in total. However, research confirming a link between losartan and insomnia is limited.

The prescribing information for Cozaar (losartan) doesn’t specifically indicate that it can cause insomnia, but it does include sleep disorders as one of a few potential side effects related to your nervous system. That said, sleep disorders are considered a “less common” adverse reaction compared to more common losartan side effects like dizziness and back pain.

Some blood pressure medications, like beta blockers, are commonly associated with insomnia, but the same effects haven’t been consistently found in people taking other types of blood pressure medications, including ARBs like losartan. Still, some people taking losartan report that the drug causes sleep disturbances.

Why might losartan or Cozaar affect sleep?

There are a few reasons why losartan or Cozaar could affect your sleep, including low blood pressure, high potassium, effects on your body’s natural melatonin secretion, and drug interactions.

High potassium  

A known side effect of ARBs like losartan is changes to your body’s electrolyte balance, which could trigger painful symptoms that keep you up at night, according to Dana Manning, Pharm.D., RD, LDN, associate professor of pharmacy practice at Wilkes University in Pennsylvania. 

One electrolyte in particular, potassium, is linked to muscle soreness and joint aches—and losartan has the potential to increase the amount of potassium in your blood, according to Roshni Patel, MD, internal medicine provider at Executive Medicine of Texas. Leg, knee, and back pain, as well as muscle pain and weakness, have all been reported as common side effects of losartan.

Melatonin changes

There is also a small amount of research suggesting that losartan can change the way your body makes melatonin, a hormone that maintains your circadian rhythm and helps you sleep. A 2014 animal study found that losartan decreased melatonin production and also altered when melatonin was released. Although the study of losartan’s effects on melatonin has been limited to animals, Dr. Patel says she has personally seen a link between losartan and insomnia in her own patients.

Low blood pressure

Another possible cause of losartan insomnia is low blood pressure, or hypotension. Your blood pressure often drops at night while you sleep, and losartan can increase this effect since it’s designed to lower your blood pressure. Low blood pressure can cause headaches, nausea, and dizziness, which may make it difficult to fall or stay asleep.

Drug interactions

Losartan can interact with some other medications and substances, and taking it with these other drugs may increase the chances of insomnia. Combining losartan and diuretics, for example, can raise your blood potassium levels and cause sleep-disrupting muscle or joint pain. Drinking alcohol while taking losartan may contribute to low blood pressure and increase symptoms like dizziness.

Common losartan side effects

While you may or may not experience losartan insomnia, there are some more common side effects you should be aware of when taking losartan for high blood pressure, including an increase in upper respiratory infections, dizziness, back pain, and cough. People taking losartan for diabetic nephropathy may also experience diarrhea, fatigue, low blood sugar, and other symptoms.

Losartan is usually tolerated well by most people taking it, but there is also the potential for serious side effects, including dangerously low blood pressure, kidney damage, muscle damage, and irregular heartbeat.

Tips for better sleep while taking losartan

If you’re struggling with insomnia while taking losartan, you may be able to manage it with a few lifestyle changes that allow you to continue taking your medication: 

• Practice good sleep hygiene: Dr. Patel says it’s important to maintain a consistent bedtime routine, avoid caffeine late in the day, and create a comfortable sleep environment for yourself. 
• Stretch before bed: If muscle aches or joint pain are contributing to sleep issues, Dr. Patel recommends gently stretching your body before bed. 
• Avoid potassium-rich foods: Because high blood potassium levels are a common cause of losartan-related pain, Dr. Patel advises her patients to avoid bananas, oranges, spinach, and other foods high in potassium while taking it.  
• Take your daily dose in the morning: If losartan is disrupting your sleep, you may be able to take it in the morning instead of at nighttime to reduce the risk of bedtime-related effects. However, you should check with your healthcare provider before making this change, since some experts recommend taking blood pressure medications at night to reduce the risk of heart attacks.

When to see your healthcare provider

Some side effects get better as your body adjusts to new medications, so if you’re having insomnia after starting losartan, it may go away once you settle into a maintenance dose. But if your sleep problems persist for more than a few weeks, Dr. Patel says you should contact your healthcare provider.

According to Dr. Patel, you should also consider talking to your healthcare provider about your sleep problems if:

• They’re caused by severe muscle cramps or joint pain
• They’re impacting your daily functioning
• They’re getting worse with time
• You frequently drive or operate heavy machinery  
• You’re considering taking sleep aids or supplements to help you sleep (because some of these can interact with losartan)

If your healthcare provider can’t help you resolve your insomnia on losartan, they may recommend that you switch to a different blood pressure medication or change your dose. However, you should never stop taking losartan without talking to your healthcare provider first. Stopping losartan suddenly can cause dangerous blood pressure spikes, according to Dr. Patel.