Diovan (valsartan) is a prescription drug taken to treat high blood pressure and lower certain cardiovascular (heart and blood vessel) risks. Diovan can cause side effects that range from mild to serious, including kidney-related side effects.

Specifically, Diovan is used to:

Diovan comes as an oral tablet and contains the active ingredient valsartan.

Keep reading to learn about the common, mild, and serious side effects Diovan can cause. For a general overview of the drug, including details about its uses, see this article.

Diovan has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effects explained” section below.

Below are just a few of the more common side effects reported by people who took Diovan in studies. These side effects can vary depending on what condition the drug is being used to treat.

More common side effects in people taking Diovan for high blood pressure include:

More common side effects in people taking Diovan for heart failure include:

More common side effects in people taking Diovan after a heart attack include:

* To learn more about this side effect, see “Kidney-related side effects” in the “Side effects explained” section below.

Mild side effects have been reported with Diovan. These include:

  • cough
  • diarrhea
  • dizziness
  • fatigue
  • flu-like symptoms
  • headache
  • nausea
  • pain in your abdomen, back, or joints
  • vertigo (feeling like the world is spinning)
  • increased blood creatinine*

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop taking Diovan unless your doctor recommends it.

Diovan may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see “Kidney-related side effects” in the “Side effects explained” section below.

Serious side effects have been reported with Diovan. These include:

If you develop serious side effects while taking Diovan, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the FDA approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Diovan, visit MedWatch.

Allergic reaction

For some people, Diovan can cause an allergic reaction. This side effect wasn’t reported in the drug’s studies, but it has happened since Diovan was approved for use.

In general, symptoms of allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Diovan.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Diovan, they may have you switch to a different treatment.

Learn more about some of the side effects Diovan may cause.

Boxed warning: Risk of fetal toxicity

Diovan has a boxed warning about the risk of fetal toxicity. A boxed warning is the most serious warning from the FDA. It alerts doctors and patients about drug effects that may be dangerous.

Based on how the drug works, Diovan may cause fetal toxicity if used during pregnancy. Fetal toxicity caused by Diovan can include problems with fetal development (commonly known as birth defects) and pregnancy loss.

What might help

If you’re pregnant or planning a pregnancy, be sure to discuss this with your doctor before starting Diovan. This boxed warning applies to all angiotensin II receptor blocker (ARB) drugs, including Diovan. It also applies to angiotensin-converting enzyme (ACE) inhibitors.

ARBs and ACE inhibitors should not be taken during pregnancy. If you have a condition that’s treated with one or more of these drugs, your doctor can review other, safer treatments with you.

If you become pregnant while taking Diovan, immediately stop taking the drug and contact your doctor right away.

Kidney-related side effects

While rare, kidney-related side effects were reported in Diovan studies. These side effects may be mild or serious.

Kidney-related side effects reported with Diovan include:

Symptoms will vary depending on the specific kidney-related side effect.

Blood creatinine and BUN levels are used by healthcare professionals to assess and monitor kidney function (plus some other uses). Increases in these levels may be a sign of kidney damage, although this isn’t always the case. Increased creatinine or BUN levels don’t typically cause symptoms but are signals of other problems within the body, such as impaired kidney function.

With sudden kidney failure, possible symptoms include fluid retention, sluggish movements, and unusual breath odor.

Factors that can increase the risk of kidney-related side effects when taking this drug include having any of the following conditions:

What might help

While taking Diovan, it’s important to remain hydrated. The amount of water a person should drink per day can vary. For example, some people with heart failure need to carefully monitor how much fluid they consume. Talk with your doctor about how much water you should aim to drink each day while taking Diovan.

Your doctor may order BUN tests and creatinine blood tests for you throughout your treatment with Diovan. If the results of these tests are high, your doctor may decrease your Diovan dosage or have you stop taking the drug.

Seek immediate medical care if you think you’re having symptoms of sudden kidney failure while taking Diovan.

Low blood pressure

Low blood pressure was a rare but reported side effect in Diovan studies. It’s most likely to occur during the first few days of treatment. The most common symptom of low blood pressure is dizziness. In rare cases, it’s possible to faint due to low blood pressure caused by Diovan.

Factors that can increase the risk of low blood pressure during Diovan treatment include:

  • diarrhea
  • vomiting
  • inadequate fluid intake
  • excessive sweating
  • taking a diuretic (water pill), such as furosemide (Lasix)

What might help

Be sure to drink enough fluid while taking Diovan. Remaining hydrated helps prevent your blood pressure and fluid volume from becoming too low. Your doctor can tell you more about how much water you should drink each day.

Contact your doctor if you have dizziness while taking Diovan. And if you faint, stop taking the drug and contact your doctor right away. They can help determine whether you should continue taking Diovan.

Keeping track of side effects

During your Diovan treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Sharing notes with your doctor will help them learn more about how Diovan affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Diovan.

Boxed warning: Risk of fetal toxicity

Diovan has a boxed warning for the risk of fetal toxicity. A boxed warning is the most serious warning from the FDA. For details, see the “Side effects explained” section above.

Other warnings

Diovan can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you. Talk with your doctor about your health history before starting Diovan. Be sure to tell them if any of the following factors apply to you:

  • high blood potassium
  • kidney condition, such as chronic kidney disease
  • if you take aliskiren (Tekturna) and have type 2 diabetes (this is a contraindication, meaning Diovan should not be taken in this case)
  • previous allergic reaction to Diovan
  • pregnancy
  • breastfeeding

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.