Leflunomide: What It Is and Why It Matters

If you’ve been diagnosed with rheumatoid arthritis or another autoimmune joint disease, you’ve probably heard the name leflunomide. It’s a pill you take once a day that helps slow down the body’s immune attack on joints. Unlike painkillers that only mask symptoms, leflunomide works on the root cause, keeping inflammation in check so you can move with less pain.

How Leflunomide Works

Leflunomide blocks an enzyme called dihydroorotate dehydrogenase, which is essential for making new DNA in fast‑growing immune cells. By limiting those cells, the drug reduces the aggressive immune response that damages joint tissue. Think of it as turning down the volume on an over‑active alarm system – the inflammation doesn’t stop completely, but it drops to a level that’s easier for your body to handle.

Typical Dosage and How to Take It

Doctors usually start adults on a 100 mg loading dose for three days, then drop down to a maintenance dose of 20 mg daily. The pill is taken with food or a glass of water, and you should try to take it at the same time each day. If you miss a dose, just take it when you remember – don’t double up. For people with liver problems or who are pregnant, doctors may adjust the dose or avoid leflunomide altogether.

It can take several weeks before you notice a real improvement, so patience is key. Keep a simple log of how your joints feel each week; that helps your doctor decide if the dose needs tweaking.

Common side effects include upset stomach, diarrhea, and headache. Some people feel rash or notice a drop in blood cell counts. If you get a fever, sore throat, or unexplained bruising, call your doctor right away – those could be signs of a more serious issue.

Leflunomide can affect your liver, so regular blood tests are a must. Your doctor will check liver enzymes before you start and then every few months. If the numbers climb, the medication may be paused or stopped.

One tricky part about leflunomide is that it stays in your body for a long time. If you ever need to stop the drug quickly – for surgery, pregnancy, or a severe infection – your doctor can give you a cholestyramine washout. This speeds up the removal of leflunomide from your system.

Interactions matter, too. Avoid combining leflunomide with live vaccines, because the weakened immune response can lead to infection. Also, tell your doctor about any other meds, especially other disease‑modifying antirheumatic drugs (DMARDs), blood thinners, or antibiotics.

Women who are planning to get pregnant should not take leflunomide. The drug can cause birth defects, and it can take months to clear from the body even after a washout. Men should also discuss family planning with their doctor, as leflunomide can affect sperm quality.

When used correctly, leflunomide can keep disease activity low for many years. Patients often report better joint function, less morning stiffness, and a slower radiographic progression of joint damage.

To get the most out of leflunomide, pair it with a healthy lifestyle: balanced diet, regular low‑impact exercise, and stress‑reduction techniques. These habits support the drug’s effect and improve overall joint health.

In short, leflunomide is a powerful tool for controlling autoimmune arthritis, but it comes with a need for monitoring and cautious use. Talk openly with your healthcare team, follow lab schedules, and report any new symptoms right away. With the right approach, you can keep your joints moving and stay ahead of flare‑ups.