Arava: Side effects and what to do about them

Quick heads-up: This article is for general education, not personal medical advice. If you think you’re having a serious reactionor you just have that gut feeling that something’s offcall your clinician right away or get emergency care.

Arava (the brand name for leflunomide) can be a real workhorse for rheumatoid arthritis: it helps calm an overactive immune system so your joints aren’t constantly acting like they’re auditioning for a fireworks show. But because it changes how the immune system behavesand because it sticks around in your body for a long timeside effects deserve a little respect (and a plan).

Let’s break down the most common Arava side effects, the rare-but-serious ones you should never ignore, and exactly what to do if your body starts sending “hello???” signals.

What Arava is (and why side effects can happen)

Arava is a disease-modifying antirheumatic drug (DMARD) used to treat active rheumatoid arthritis. Instead of just covering up pain, it aims to slow the disease process by dialing down immune activity that drives inflammation.

That immune “volume knob” effect is the pointbut it’s also why side effects can show up. When immune activity shifts, your GI tract, skin, liver, lungs, nerves, and blood counts may react. Also, Arava’s active form (teriflunomide) has a long half-life. Translation: if you stop Arava, it can take a long time to fully clear unless you use a specific “washout” procedure.

The most common side effects (and what to do about them)

Most people who have side effects experience them earlyoften in the first weeks to a few months. Some improve as your body adjusts. The goal is to manage what’s manageable, and recognize when “annoying” is turning into “dangerous.”

1) Diarrhea (the classic Arava complaint)

If Arava had a signature move, it would be this one. Diarrhea is one of the most common side effects and can happen in a noticeable chunk of patients. The good news: it often improves over time.

What you can do:

• Hydrate like it’s your job: Water is good; oral rehydration solutions are better if symptoms are frequent.
• Go gentle on your gut: Try bland foods (toast, rice, bananas), and avoid greasy/spicy meals for a bit.
• Ask before you medicate: Over-the-counter anti-diarrheal meds may be reasonable for some people, but check with your clinicianespecially if you have fever, blood in stool, or severe abdominal pain.
• Call your clinician if: diarrhea is severe, persistent, or causing dizziness, dehydration, or weight loss. Dose adjustment is sometimes an option.

2) Nausea, upset stomach, and dyspepsia (a.k.a. “my stomach is unimpressed”)

Some people notice nausea, stomach discomfort, or indigestion/heartburn.

What you can do:

• Take Arava exactly as prescribed. If your clinician OKs it, taking it with food may help some people.
• Eat smaller meals and avoid lying down right after eating if heartburn is an issue.
• If nausea is persistent, ask about timing changes, supportive meds, or whether another DMARD strategy makes more sense.

3) Headache

Headaches can occur, especially early.

What you can do:

• Hydrate and aim for consistent sleep (your brain loves routine more than it admits).
• Ask your clinician which pain relievers are safe for you, particularly if you have liver concerns or take other medications.

4) Rash or skin irritation

Mild rashes can happen. But because rare, severe skin reactions are also possible, new rashes deserve attention.

What you can do:

• If the rash is mild: take photos, note timing, and contact your clinician for guidance.
• Get urgent care if you have blistering, peeling skin, sores in your mouth/eyes, widespread rash, fever, or you feel very ill.

5) Hair thinning (alopecia)

Hair thinning can be distressingeven when it’s not medically dangerous. It may be temporary and sometimes improves with time or after dose changes.

What you can do:

• Be gentle with hair care: avoid harsh bleaching, high heat, and tight hairstyles.
• Ask your clinician to check for other contributors (thyroid issues, iron deficiency, active inflammation, stress).
• Discuss whether the benefit you’re getting from Arava outweighs this side effect for you.

6) Mild infections (like “I caught another cold”)

Because Arava affects immune function, infections may be more likely or more stubborn.

What you can do:

• Don’t ignore fevers, worsening cough, or symptoms that linger longer than usual.
• Tell your rheumatology team about infections promptly, especially if you’re also on other immunosuppressants.
• Ask before getting vaccines; live vaccines are generally avoided during treatment.

7) Higher blood pressure

Arava can raise blood pressure in some people, so periodic checks matter even if you’ve never cared about your numbers before.

What you can do:

• Check blood pressure at baseline and periodically (home cuff, pharmacy kiosk, or clinic).
• Report sustained increases to your cliniciandon’t just blame “traffic” forever.

Serious side effects: warning signs you should not “wait out”

Most people won’t experience the severe reactions belowbut if they happen, acting quickly can make a big difference. When in doubt, call your clinician. If symptoms are severe or rapidly worsening, get emergency care.

1) Liver injury (boxed warning)

Arava can cause significant liver injury, including rare cases of fatal liver failure. Risk is higher if you have pre-existing liver disease, elevated liver enzymes before starting, or you take other medications that can affect the liver.

Call your clinician immediately if you notice:

• Yellowing of skin or eyes (jaundice)
• Dark urine, pale stools
• Persistent nausea, vomiting, loss of appetite
• Severe fatigue, right-upper-abdominal pain
• Unusual bruising or bleeding

What typically happens next: your clinician may order urgent liver tests, stop Arava, and consider an accelerated elimination (“washout”) if liver injury is suspected.

2) Pregnancy risk (boxed warning) and contraception

Arava is contraindicated in pregnancy because it can cause fetal harm. People who can become pregnant usually need pregnancy testing before starting and effective contraception during treatment.

Important twist: because Arava can linger in the body, contraception may be needed for an extended period after stopping unless a washout procedure is performed.

If pregnancy occurs while taking Arava: stop the medication and contact your clinician immediately. A washout procedure is typically recommended to reduce drug levels as quickly as possible.

3) Bone marrow suppression (low blood counts)

Arava can lower white blood cells, red blood cells, or platelets. This may increase infection risk, fatigue, and bleeding risk.

Call promptly for:

• Frequent infections or fever
• Unusual bruising, bleeding gums, nosebleeds
• Extreme fatigue, shortness of breath, pale skin

4) Serious infections (including opportunistic infections and TB risk)

Arava can increase susceptibility to serious infections. Clinicians often screen for latent tuberculosis before starting, especially depending on risk factors and local practice.

Seek urgent care for:

• High fever, chills, confusion
• Shortness of breath, chest pain
• Severe weakness, signs of sepsis

5) Severe skin reactions (SJS/TEN/DRESS)

These are rare but life-threatening. The key is not to “Google-cope” your way through them.

Go to emergency care if you have:

• Rash with blistering or peeling
• Mouth sores, eye pain/redness
• Rash plus fever or facial swelling
• Widespread rash with feeling very ill

6) Lung problems (interstitial lung disease / pneumonitis)

Arava has been associated with interstitial lung disease, including worsening of existing lung disease, and it can occur at any time during therapy.

Get medical advice urgently for:

• New or worsening cough
• Shortness of breath (with or without fever)
• Unexplained chest tightness or rapid breathing

7) Peripheral neuropathy (nerve symptoms)

Some people develop nerve problems such as numbness, tingling, burning pain, or weaknessoften in hands or feet.

Don’t ignore:

• New tingling/numbness that persists
• Burning sensations, unusual sensitivity
• Weakness or trouble with balance

Early recognition matters because stopping the medication sooner may improve the chance of recovery.

The “washout” plan: how Arava can be removed faster

Here’s the part that surprises many people: Arava can stay in your body for up to two years without an accelerated elimination procedure. That long tail is why pregnancy planning and serious side effects often involve a washout.

When a washout may be considered

• Pregnancy occurs (or pregnancy is desired sooner after stopping)
• Serious liver injury is suspected
• Severe infection, bone marrow suppression, severe skin reaction, neuropathy, or lung toxicity occurs
• Other severe hypersensitivity reactions

Common washout options clinicians use

Clinicians may use one of these accelerated elimination approaches:

• Cholestyramine (often 8 g three times daily for 11 days), or
• Activated charcoal (often 50 g every 12 hours for 11 days).

Afterward, clinicians may confirm drug levels with blood testing done twice at least 14 days apart, depending on the clinical situation (especially for pregnancy planning).

Real-life note: washout regimens can cause their own GI side effects (because, frankly, cholestyramine is not winning any taste contests). If your clinician prescribes washout, ask how to manage constipation, bloating, nausea, or diarrhea during the process.

Monitoring: the side-effect prevention system you don’t want to skip

Monitoring is how clinicians catch many problems earlybefore they become emergencies.

Typical checks before and during treatment

• Liver tests (ALT/AST): commonly monitored at least monthly early on, then spaced out if stable.
• Blood counts (CBC): checked at baseline and regularly to detect low white cells/platelets/anemia.
• Blood pressure: checked before starting and periodically thereafter.
• Pregnancy testing: for people who can become pregnant, before starting and as clinically appropriate.
• TB screening: often performed before starting, particularly based on risk factors and clinician practice.

If you’re also taking methotrexate or other immunosuppressive drugs, monitoring may be more frequent.

Drug interactions and lifestyle choices that affect side effects

Side effects aren’t just about the pillthey’re also about everything else in the mix.

Alcohol and liver stress

Because liver injury is a known risk, many clinicians recommend avoiding alcohol or keeping it very limited. If you drink, be upfrontyour liver doesn’t benefit from your politeness.

Other medications

Tell your clinician about everything you take: prescriptions, over-the-counter meds, supplements, and herbal products. Some medications can increase liver risk or interact through shared pathways.

• If you take warfarin or other blood thinners, you may need closer monitoring.
• Some drugs may raise or lower exposure to Arava’s active form, changing side effect risk.

Vaccines

Live vaccines are generally avoided during Arava treatment. For routine vaccines (flu, COVID-19, pneumonia, shingles), ask your rheumatology team for timing guidance that fits your health status and other meds.

Pregnancy, contraception, and breastfeeding

Contraception planning is essential for anyone who can become pregnant and for males with partners who can become pregnant. If you want to conceive, bring it up earlybecause with Arava, “early” is a strategy, not a vibe.

Breastfeeding is generally not recommended during Arava therapy; ask your clinician about safer alternatives if this is relevant to you.

A practical “what to do” checklist for side effects

Step 1: Sort the symptom into one of three buckets

• Manage-at-home (with a message): mild diarrhea, mild nausea, mild headache, mild hair thinning.
• Call soon: persistent GI symptoms, rash, rising blood pressure, frequent infections, new tingling/numbness.
• Urgent/emergency: jaundice, dark urine, severe weakness, high fever, shortness of breath, blistering rash, confusion, chest pain.

Step 2: Track patterns (without turning your notes into a novel)

Write down:

• When the symptom started
• How severe it is (1–10)
• What makes it better or worse
• Any new meds/supplements, alcohol intake, or recent illness

Step 3: Know the “stop and call” triggers

Even if you’re not sure it’s Arava, call promptly for:

• Symptoms of liver trouble (jaundice, dark urine, severe fatigue, RUQ pain)
• Pregnancy or suspected pregnancy
• Severe rash or rash with fever
• Shortness of breath or worsening cough
• New neuropathy symptoms (persistent numbness/tingling)

FAQ: quick answers people actually want

How long do Arava side effects last?

Mild effects like diarrhea or headache can improve over weeks as your body adjusts. Others (like elevated liver enzymes or blood count changes) may show up on labs before you feel anythingwhich is why monitoring matters.

Can dose changes help?

Sometimes. Many people take 20 mg daily, but some clinicians adjust dosing if side effects are persistent. Never change your dose on your ownArava is not a “DIY dosing” medication.

Why is everyone so serious about pregnancy with Arava?

Because the risk is real and the drug can linger. With the right planning (including washout when appropriate), many people navigate this safelybut it has to be intentional.

Bonus: real-world experiences with Arava side effects (what people commonly report)

Clinical trial lists are helpful, but they can feel like reading a car manual when you just want to know, “Okay… what does this feel like on a random Tuesday?” Here are themes that rheumatology clinics commonly hear from patientswithout pretending everyone’s body reads the same script.

The first month often feels like a “getting-to-know-you” phase. Many people report that the earliest side effects are GI-relatedusually looser stools, mild nausea, or that vague “my stomach is slightly annoyed” sensation. A lot of patients notice it’s worse in the first couple of weeks and then settles down, especially when they stay hydrated and avoid foods that already trigger them. Some people learn quickly which meals are “safe” and which ones are basically a dare (hello, extra-spicy takeout).

Diarrhea is the side effect most likely to spark a phone call. Not because it’s always severe, but because it’s disruptive. Patients often describe it as inconvenient and unpredictable rather than dangerousuntil it becomes frequent enough to cause fatigue, dehydration, or weight loss. Clinicians may suggest supportive steps, check for other causes (like infection), and sometimes adjust the dose if symptoms persist. The most helpful mindset is: don’t suffer silently, but also don’t assume the first rough week means the medication will never work for you.

Hair thinning can be emotionally loud even when medically quiet. People commonly say they notice extra shedding in the shower or on a brush. For some, it’s mild and temporary; for others, it becomes a deciding factor in whether they continue Arava. What patients often find reassuring is a proactive plan: gentle hair care, checking labs for other contributors, and an honest discussion about trade-offs. It’s not “vain” to careit’s human.

Lab results can be the first clue before symptoms show up. Some patients feel completely fine and are surprised when liver enzymes or blood counts shift. This is where monitoring earns its keep. People who do best long-term often treat lab appointments like oil changes: not exciting, but very protective. When abnormalities are caught early, clinicians can adjust treatment before there’s real harm.

Side effects feel bigger when you’re also juggling other meds. Many rheumatoid arthritis treatment plans involve combinations (or transitions) between DMARDs. Patients frequently report that it’s hard to tell which medication is responsible for what. That’s why symptom trackingsimple and consistentcan be powerful. It helps your clinician decide whether Arava is the likely culprit, whether another medication is interacting, or whether something unrelated (like a viral illness) is in the mix.

The biggest “win” patients describe isn’t perfectionit’s control. People who stay on Arava successfully often say the turning point is having a clear playbook: what’s normal early on, what’s not, when to call, and what tests they’ll be doing. Once that uncertainty fades, the day-to-day feels less scary. And honestly, that’s a side effect worth keeping: peace of mind.

Conclusion

Arava can be an effective DMARD for rheumatoid arthritis, but side effects range from mildly annoying (diarrhea, headache, nausea) to medically serious (liver injury, severe infections, severe skin reactions, lung toxicity, neuropathy, and pregnancy-related risks). The best strategy is not panicit’s preparation: regular labs, blood pressure checks, contraception planning, and fast communication when warning signs show up. If you and your rheumatology team treat side effects like a problem to solve (not a personal failure), you’ll make smarter decisions and stay safer.