Leflunomide is a medication used to manage certain autoimmune conditions. This article provides an overview of its effectiveness and potential side effects, helping individuals understand what to expect when prescribed this drug.
Understanding Leflunomide and Its Uses
Leflunomide, also known as Arava, is a disease-modifying antirheumatic drug (DMARD). It is primarily prescribed for adults with active moderate-to-severe rheumatoid arthritis (RA) and psoriatic arthritis (PsA). In these conditions, the immune system mistakenly attacks the body’s own tissues, leading to inflammation, pain, and joint damage.
The medication works by dampening the immune system’s activity, which helps reduce inflammation and slow the progression of joint damage. Specifically, leflunomide is a prodrug that converts to its active metabolite, teriflunomide (also known as A77 1726), after oral administration. This active metabolite inhibits an enzyme called dihydroorotate dehydrogenase (DHODH), which is involved in the synthesis of pyrimidines, components needed for DNA and RNA. By limiting pyrimidine synthesis, leflunomide interferes with the proliferation of rapidly dividing cells, particularly activated T and B lymphocytes that contribute to autoimmune responses.
Common Patient Experiences: Effectiveness and Side Effects
Many individuals treated with leflunomide experience an improvement in their symptoms, with over 70% of people with rheumatoid arthritis showing benefit. Patients often report a reduction in pain, swelling, and stiffness in their joints, leading to improved physical function. Some may even achieve remission, where their arthritis symptoms largely disappear. The initial effects of leflunomide typically become noticeable within four to eight weeks, though the full therapeutic benefit may take four to six months to develop.
Individual responses to leflunomide can vary. Gastrointestinal issues are commonly reported, affecting up to 20% of users, and can include diarrhea, nausea, stomach pain, and loss of appetite. These symptoms often lessen after a few weeks of treatment.
Other frequently reported side effects include hair thinning or loss, which is usually reversible, and skin rashes, occurring in up to 10% of patients. Some individuals may also experience headaches, dizziness, or a slight increase in blood pressure. Elevated liver enzymes, which may indicate liver damage, are a more serious, though rare, concern. While often mild and reversible upon stopping the medication, severe liver injury, including liver failure, has been reported in rare cases. Patients should also be aware of an increased risk of infections due to leflunomide’s immune-suppressing effects.
Managing Treatment and Important Considerations
Regular monitoring is a standard part of treatment with leflunomide due to its impact on liver and blood cells. Blood tests, including complete blood counts (CBC) and liver function tests (LFTs), are typically performed at baseline, then every two to four weeks for the first few months, and subsequently every one to three months. This testing helps detect any changes, such as a drop in white blood cell or platelet counts, or elevated liver enzymes, even before symptoms appear.
Leflunomide carries warnings and contraindications. It is strongly contraindicated in pregnancy due to the potential for fetal harm. Women of childbearing potential must use reliable contraception during treatment and for a prolonged period afterward. Men should also be aware of potential male-mediated fetal toxicity and discuss contraception with their healthcare provider. The medication is also not recommended for individuals with pre-existing acute or chronic liver disease, or those with significantly elevated liver enzymes before starting treatment.
Discussing all medications and supplements with a healthcare provider is important due to drug interactions. For instance, combining leflunomide with methotrexate may increase the risk of liver damage. Other drugs like warfarin, rifampin, and certain antibiotics, as well as some statins, can interact with leflunomide, necessitating careful monitoring or dose adjustments.
Leflunomide has a long half-life, meaning its active metabolite can remain in the body for an extended period, typically one to four weeks, but potentially up to two years, even after stopping the medication. If discontinuation is necessary, particularly due to severe side effects, pregnancy, or before starting another immunosuppressive DMARD, a “washout” procedure may be recommended. This procedure involves taking activated powdered charcoal or cholestyramine for about 11 days to rapidly eliminate the drug and reduce its half-life to approximately one to two days.