10 Side Effects of Arava You Need to Know

Rheumatoid arthritis (RA) is a condition that causes pain and swelling in the joints. It’s an autoimmune disorder, meaning your immune system mistakenly attacks your own body. Arava (leflunomide) is one possible treatment for this condition. This disease-modifying antirheumatic drug (DMARD) works by blocking the overproduction of certain immune cells.

Like all medications, Arava has possible side effects. These include common side effects, such as diarrhea and nausea, as well as serious side effects, like liver damage.

Here, we’ll cover 10 Arava side effects and ways you might be able to manage them.

1. Diarrhea

Diarrhea is the most common side effect of Arava. In clinical trials, up to 27% of people taking Arava reported diarrhea as a side effect. This is typically temporary and should resolve after the first few weeks of treatment. Experts don’t fully understand why this side effect happens.

Be sure to stay hydrated if you experience loose stools, especially if your diarrhea persists. Over-the-counter (OTC) antidiarrheals, like Imodium A-D (loperamide), may help lessen diarrhea while your body adjusts to Arava.

If you’re not seeing improvement after a couple of weeks, talk to your healthcare provider. They may suggest lowering your dose to see if that helps.

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2. Rash

Rash is also a common Arava side effect. In studies, up to 12% of people taking Arava experienced a skin rash as a side effect. But even though it’s common, you should let your healthcare provider know if this happens to you. This is an important precaution. As we’ll discuss later in this list, some rashes can be serious.

For mild rashes, your healthcare provider will likely have you continue taking Arava. They may suggest medications to help relieve itching and redness, like steroid creams or antihistamines. For more severe rashes, you may be told to stop taking Arava. In serious cases, treatment in a hospital may be needed.

3. Hair loss

Hair loss (alopecia) is another common Arava side effect. As mentioned earlier, this medication helps stop the overgrowth of certain cells. In some cases, this may also affect the growth of hair cells. This side effect usually isn’t severe and shouldn’t cause your hair to fall out in clumps.

If you notice hair loss that you’re uncomfortable with, let your healthcare provider know. They may be able to offer tips to manage this Arava side effect. They might also help you explore other RA treatment options.

4. High blood pressure

Arava can also cause high blood pressure. This side effect likely stems from the medication’s effects on the body’s “fight or flight” system. A rise in blood pressure may be first noticed about 2 to 4 weeks after starting Arava.

It’s recommended to monitor blood pressure regularly while taking Arava, especially while your body is still getting used to the medication. Ask your healthcare provider about safe and unsafe blood pressure ranges for you. You may also want to keep and share a log of your at-home blood pressure readings with your provider.

5. Nausea

Nausea is another common Arava side effect. In clinical trials, up to 13% of people taking Arava experienced nausea. Less commonly, about 5% of study participants reported vomiting as a side effect of Arava.

Taking Arava with food may help lessen nausea and vomiting. You can also ask your healthcare provider about OTC nausea medications, such as Pepto Bismol (bismuth subsalicylate). If this side effect doesn’t go away or seems excessive, let your provider know.

6. Headache

Headache is a common side effect reported for many medications, including Arava. In clinical trials, up to 13% of people experienced headaches while taking Arava. Experts don’t know why this side effect happens.

Drinking plenty of water and getting some extra rest can help relieve headaches. There are also OTC headache medications that can help. Popular choices include Advil (ibuprofen) and Excedrin Migraine (acetaminophen/aspirin/caffeine).

Keep in mind that OTC headache medications are meant for short-term use. They can cause rebound headaches if taken too frequently. If you find yourself taking doses regularly, talk to your healthcare provider.

7. Back pain

Back pain can happen while taking Arava. This side effect happened to around 6% of people taking Arava in studies. The reasoning for this side effect is unknown.

Ice or heat packs can be soothing for back pain. OTC pain relievers, such as Tylenol (acetaminophen) or Aleve (naproxen), may also be an option for relief. And there’s several stretches you can do at home that can be helpful for lower back pain.

8. Liver damage

Changes in liver function tests (blood tests that measure how well your liver is working) are possible after taking Arava. Studies of Arava found that up to 10% of people had changes in their liver enzymes (proteins). You can’t generally feel these changes. But this side effect is usually reversible if you stop the medication.

More rarely, Arava has been known to cause liver damage. This is a serious side effect that can be life-threatening. Because of this, Arava contains a boxed warning (the strictest FDA warning for medications) about possible liver damage. If you already have liver problems, Arava may not be the safest option for you.

9. Serious skin reactions

Very rarely, Arava can cause serious skin reactions, such as Stevens-Johnson syndrome or Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome. These reactions are medical emergencies if they happen. If you develop a serious skin reaction while taking Arava, the medication should be stopped and you should seek medical attention immediately.

10. Higher risk for serious infections

Taking Arava can raise your risk for developing serious infections, like pneumonia or tuberculosis. This is because Arava suppresses the immune system in order to treat RA. These infections can be fatal in some cases.

If you have an active infection when first starting Arava, your healthcare provider will have you wait until you recover to start it. It’s also recommended to have your blood work monitored regularly during treatment to make sure your immune cell levels aren’t getting too low.

When should I contact my healthcare provider about Arava side effects?

When to contact your healthcare provider depends on the type of side effects you’re having. Severe and/or bothersome side effects warrant a call to your healthcare provider immediately. For milder side effects, you’ll likely be able to manage them at home. But you should still let your healthcare provider know about them so they can help you decide whether to continue taking Arava.

If your healthcare provider recommends stopping Arava, there’s a specific way to stop this medication. It’s called an accelerated drug elimination procedure. The reason for this is to clear the medication quickly out of the body. You shouldn’t try to stop Arava without your healthcare provider’s guidance.

Arava lasts in your body for a long time. Without an accelerated drug elimination procedure, it can take up to 2 years for it to get out of your system. This method is especially important if you’re experiencing a serious side effect to Arava.

After completing the procedure, your healthcare provider will check your blood levels to make sure enough has been removed from your body. If you still have too much medication in your system, you may need to repeat the procedure.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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