Leflunomide

About Leflunomide

Leflunomide, converted in the body to its active form teriflunomide, blocks an enzyme cells use to make pyrimidines (building blocks of DNA and RNA) and slows cell multiplication. It is labeled for adults with active rheumatoid arthritis; safety and effectiveness in children have not been established. The usual and maximum dose is 20 mg once a day, which may be lowered to 10 mg if 20 mg is not tolerated. People at low risk of liver injury and low blood counts may start with a loading dose of 100 mg once a day for three days; those at higher risk, such as people also taking methotrexate or other immune-suppressing drugs, start at 20 mg.

The boxed warnings cover embryo-fetal toxicity and liver injury. Leflunomide caused birth defects and embryo deaths in animals, so it is contraindicated in pregnancy: pregnancy is ruled out first, and women who could become pregnant use effective birth control during treatment and any elimination procedure. Severe liver injury, including fatal liver failure, has been reported; it is not used with existing acute or chronic liver disease or an ALT above twice the upper limit of normal, and interrupted if ALT rises above three times normal. It is not recommended with severe immunodeficiency, bone marrow dysplasia or severe, uncontrolled infections, and the label also warns of serious infections, low blood counts, serious skin reactions, skin ulcers, peripheral neuropathy, interstitial lung disease and raised blood pressure. It must not be taken with severe liver impairment, with teriflunomide, or by anyone allergic to it. Diarrhea, respiratory infections, nausea, headache, rash, abnormal liver tests and indigestion are the most common side effects.

Teriflunomide leaves the body slowly, taking up to two years to fall below 0.02 mg/L. The accelerated elimination procedure, 8 grams of cholestyramine three times a day or 50 grams of activated charcoal every 12 hours, each for 11 days, followed by two blood tests at least 14 days apart to confirm the level, speeds this up. It is used before a planned pregnancy (men who wish to father a child stop leflunomide, then either use it or wait until tests confirm a low level), if pregnancy occurs, and after a severe reaction such as liver injury or serious infection. Tuberculosis screening, ALT, a blood count, blood pressure and, where relevant, a pregnancy test come first; ALT and blood counts are then checked monthly for six months and every six to eight weeks after that. Live vaccines are not recommended, and breastfeeding is stopped during treatment.

Taking Leflunomide

How to take it

Usually once a day, exactly as directed, including any larger dose your prescriber orders for the first three days. The label reports that a high-fat meal did not significantly change blood levels. Keep every blood test appointment, and do not stop it without talking to your prescriber.

If you miss a dose

Take the missed dose as soon as you remember, unless it is almost time for the next one; then skip it. Do not take a double dose.

Storage

At room temperature, protected from light, heat and moisture, out of reach of children. Use a take-back program rather than flushing it.

Interactions to know about

It must not be taken with teriflunomide. With warfarin the INR is monitored closely, rosuvastatin is kept to 10 mg a day, and repaglinide and other drugs cleared by CYP2C8 or CYP1A2, as well as the type or dose of birth control pill, may need review. Methotrexate and other drugs that can harm the liver add to the risk of liver injury.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Leflunomide differs from pharmacy to pharmacy

Generic leflunomide comes from many makers, all rated equivalent to Arava, yet pharmacies price it in different ways, some from what they paid plus a fee and others from a published list price, so quotes for the same tablet can differ widely. A prescription that names Arava without allowing substitution is quoted at the brand price.

The tablets are only part of the cost of treatment: liver tests and blood counts continue every six to eight weeks after the first six months, and any cholestyramine or activated charcoal for an elimination procedure is priced separately.

Ways to pay less for Leflunomide without insurance

• Make sure the prescription allows generic substitution, so you are quoted for generic leflunomide rather than Arava.
• Ask whether leflunomide is on the pharmacy’s flat-price generic list, and compare more than one pharmacy.
• If a loading dose is prescribed, ask the pharmacy before the first fill how it will be supplied, since the 100 mg tablet is listed as discontinued and no generic comes in that strength.
• Once your dose and blood tests are stable, ask for a ninety-day supply.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Leflunomide

1. 1.When are my liver tests, blood counts and blood pressure checks due?
2. 2.What birth control should I use, and what should I do if I want to become pregnant or father a child?
3. 3.Which signs of liver trouble, infection or a skin reaction mean I should call at once?
4. 4.Does it interact with my warfarin, rosuvastatin, birth control pills or methotrexate?

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