Leflunomideside effects
leflunomide 20 MG Oral Tablet
Adverse reactions
The following serious adverse reactions are described elsewhere in the labeling: Hepatotoxicity Immunosuppression Bone marrow suppression Stevens-Johnson syndrome and toxic epidermal necrolysis Peripheral neuropathy Interstitial lung disease The most commonly reported adverse reactions (≥10%) regardless of relation to leflunomide treatment were diarrhea, respiratory infection, nausea, headache, rash, abnormal liver enzymes, dyspepsia. To report SUSPECTED ADVERSE REACTIONS, contact Chartwell RX, LLC. at 1-845-232-1683 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch
6.1 Clinical
Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. In clinical studies (Trials 1, 2, and 3), 1,865 patients were treated with leflunomide administered as either monotherapy or in combination with methotrexate or sulfasalazine. Patients ranged in age from 19 to 85 years, with an overall median age of 58 years. The mean duration of RA was 6 years ranging from 0 to 45 years. Elevation of Liver Enzymes Treatment with leflunomide was associated with elevations of liver enzymes, primarily ALT and AST, in a significant number of patients; these effects were generally reversible. Most transaminase elevations were mild (≤ 2-fold ULN) and usually resolved while continuing treatment. Marked elevations (>3-fold ULN) occurred infrequently and reversed with dose reduction or discontinuation of treatment. Table 1 shows liver enzyme elevations seen with monthly monitoring in clinical trials Trial 1 and Trial 2. It was notable that the absence of folate use in Trial 3 was associated with a considerably greater incidence of liver enzyme elevation on methotrexate. Table 1. Liver Enzyme Elevations >3-fold Upper Limits of Normal (ULN) in Patients with RA in Trials 1, 2, and 3** Trial 1 Trial 2 Trial 3* LEF 20 mg/day (n=182) PL (n=118) MTX 7.5-15 mg/wk (n=182) LEF 20mg/day (n=133) PL (n=92) SSZ 2.0 g/day LEF 20 mg/day (n=501) MTX 7.5-15 mg/wk (n=498) ALT(SGPT)>3-fold ULN (n%) 8 3 5 2 1 2 13 83 Reversed to ≤ 2-fold ULN: 8 3 5 2 1 2 12 82 Timing of Elevation 0 - 3 Months 4 - 6 Months 7 - 9 Months 10 - 12 Months 6 1 1 - 1 1 1 - 1 3 1 - 2 - - - 1 - - - 2 - - - 7 1 - 5 27 34 16 6 LEF = leflunomide, MTX = methotrexate, PL = placebo, SSZ = sulfasalazine, ULN = Upper limit of normal *Only 10% of patients in Trial 3 received folate. All patients in Trial 1 received folate. In a 6 month study of 263 patients with persistent active rheumatoid arthritis despite methotrexate therapy, and with normal LFTs, leflunomide was administered to a group of 130 patients starting at 10 mg per day and increased to 20 mg as needed. An increase in ALT greater than or equal to three times the ULN was observed in 3.8% of patients compared to 0.8% in 133 patients continued on methotrexate with placebo. Most Common Adverse Reactions The most common adverse reactions in leflunomide-treated patients with RA include diarrhea, elevated liver enzymes (ALT and AST), alopecia and rash. Table 2 displays the most common adverse reactions in the controlled studies in patients with RA at one year (≥5% in any leflunomide treatment group). Table 2. Percentage of Patients with Adverse Events ≥ 5% In Any Leflunomide Treated Group in all RA Studies in Patients with RA Placebo-Controlled Trials Active-Controlled Trials All RA Studies Trial 1 and 2 Trial 3 1 LEF 20 mg/day (N=315) PL (N=210) SSZ 2.0g/day (N=133) MTX 7.5-15 mg/wk (N=182) LEF 20 mg/day (N=501) MTX 7.5–15 mg/wk (N=498) LEF (N=1339) 2 Diarrhea 27% 12% 10% 20% 22% 10% 17% Headache 13% 11% 12% 21% 10% 8% 7% Nausea 13% 11% 19% 18% 13% 18% 9% Rash 12% 7% 11% 9% 11% 10% 10% Abnormal Liver Enzymes 10% 2% 4% 10% 6% 17% 5% Alopecia 9% 1% 6% 6% 17% 10% 10% Hypertension 3 9% 4% 4% 3% 10% 4% 10% Asthenia 6% 4% 5% 6% 3% 3% 3% Back Pain 6% 3% 4% 9% 8% 7% 5% GI/Abdominal Pain 6% 4% 7% 8% 8% 8% 5% Abdominal Pain 5% 4% 4% 8% 6% 4% 6% Allergic Reaction 5% 2% 0% 6% 1% 2% 2% Bronchitis 5% 2% 4% 7% 8% 7% 7% Dizziness 5% 3% 6% 5% 7% 6% 4% Mouth Ulcer 5% 4% 3% 10% 3% 6% 3% Pruritus 5% 2% 3% 2% 6% 2% 4% Rhinitis 5% 2% 4% 3% 2% 2% 2% Vomiting 5% 4% 4% 3% 3% 3% 3% Tenosynovitis 2% 0% 1% 2% 5% 1% 3% LEF = leflunomide, MTX = methotrexate, PL = placebo, SSZ = sulfasalazine 1 Only 10% of patients in Trial3 received folate. All patients in Trial 1 received folate; none in Trial 2 received folate. 2 Includes all controlled and uncontrolled trials with leflunomide (duration up to 12 3 Hypertension as a preexisting condition was overrepresented in all leflunomide treatment groups in phase III trials. Adverse events during a second year of treatment with leflunomide in clinical trials were consistent with those observed during the first year of treatment and occurred at a similar or lower incidence. Less Common Adverse Reactions In addition, in controlled clinical trials, the following adverse events in the leflunomide treatment group occurred at a higher incidence than in the placebo group. These adverse events were deemed possibly related to the study drug.
Blood and Lymphatic System: leukocytosis, thrombocytopenia;
Cardiovascular: chest pain, palpitation, thrombophlebitis of the leg, varicose vein;
Eye: blurred vision, eye disorder, papilledema, retinal disorder, retinal hemorrhage;
Gastrointestinal: alkaline phosphatase increased, anorexia, bilirubinemia, flatulence, gamma- GT increased, salivary gland enlarged, sore throat, vomiting, dry mouth;
General Disorders: malaise;
Immune System: anaphylactic reaction;
Infection: abscess, flu syndrome, vaginal moniliasis;
Nervous System: dizziness, headache, somnolence;
Respiratory System: dyspnea;
6.2 Post Marketing
Experience The following additional adverse reactions have been identified during postapproval use of leflunomide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Blood and Lymphatic System: agranulocytosis, leukopenia, neutropenia, pancytopenia;
Infection: opportunistic infections, severe infections including sepsis;
Gastrointestinal: acute hepatic necrosis, colitis, including microscpic colitis, hepatitis, jaundice/cholestasis, pancreatitis; severe liver injury such as hepatic failure Immune System: angioedema;
Nervous system: peripheral neuropathy;
Respiratory: interstitial lung disease, including interstitial pneumonitis and pulmonary fibrosis, which may be fatal; pulmonary hypertension;
Skin and Appendages: erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, vasculitis including cutaneous necrotizing vasculitis, cutaneous lupus erythematosus, pustular psoriasis or worsening psoriasis.
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective December 17, 2025. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
Warnings
For external use only Allergy alert: Diclofenac may cause a severe allergic reaction, especially in people allergic to aspirin. Symptoms may include:
hives
asthma (wheezing)
skin reddening
blisters
facial swelling
shock
rash If an allergic reaction occurs, stop use and seek medical help right away. Liver warning: This product contains diclofenac. Liver damage may occur if you apply
more or for a longer time than directed
when using other drugs containing diclofenac Stomach bleeding warning: This product contains an NSAID, which may cause severe stomach bleeding. The chance is small but higher if you
are age 60 or older
have had stomach ulcers or bleeding problems
take a blood thinning (anticoagulant) or steroid drug
take other drugs containing prescription or nonprescription NSAIDs (aspirin, ibuprofen, naproxen, or others)
have 3 or more alcoholic drinks every day while using this product
apply more or for longer than directed Heart attack and stroke warning: NSAIDs, except aspirin, increase the risk of heart attack, heart failure, and stroke. These can be fatal. The risk is higher if you use more than directed or for longer than directed. Do not use
if you have ever had an allergic reaction to any other pain reliever or to a fever reducer
for strains, sprains, bruises or sports injuries. This product has not been shown to work for these types of injuries.
right before or after heart surgery
on more than 2 body areas at the same time
in the eyes, nose or mouth Ask a doctor before use if
you have problems or serious side effects from taking pain relievers or fever reducers
stomach bleeding warning applies to you
you have a history of stomach problems, such as heartburn
you have high blood pressure, heart disease, liver cirrhosis, kidney disease, asthma, or had a stroke
you are taking a diuretic
you are under age 18 years. It is not known if this drug works or is safe in children under age 18 years. Ask a doctor or pharmacist before use if you are
under a doctor’s care for any serious condition
taking any other drug When using this product
avoid contact with eyes, nose, or mouth
if eye contact occurs, rinse thoroughly with water Stop use and ask a doctor if
pain gets worse or lasts more than 21 days
redness or swelling is present in the painful area
fever occurs
skin irritation occurs
any new symptoms appear. These could be signs of a serious condition.
you experience any of the following signs of stomach bleeding:
feel faint
have bloody or black stools
vomit blood
have stomach pain that does not get better
you have symptoms of heart problems or stroke:
chest pain
trouble breathing
leg swelling
weakness in one part or side of body
slurred speech If pregnant or breast-feeding, ask a health professional before use. It is especially important not to use this product during the last 3 months of pregnancy unless definitely directed to do so by a doctor because it may cause problems in the unborn child or complications during delivery. Keep out of reach of children. If swallowed, get medical help or contact a Poison Control Center right away (1-800-222-1222).
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective December 17, 2025. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
Contraindications
Leflunomide tablets are contraindicated in: Pregnant women. Leflunomide may cause fetal harm. If a woman becomes pregnant while taking this drug, stop leflunomide, apprise the patient of the potential hazard to the fetus, and begin a drug elimination procedure. Patients with severe hepatic impairment. Patients with known hypersensitivity to leflunomide or any of the other components of leflunomide tablets. Known reactions include anaphylaxis. Patients being treated with teriflunomide. Pregnancy. Severe hepatic impairment. Hypersensitivity to leflunomide tablet or any of its inactive components. Current teriflunomide treatment.
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective December 17, 2025. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
This page reproduces regulatory text for reference. It is not medical advice, and KenyRx is not a pharmacy or a prescriber. Talk to a doctor or pharmacist about whether a medicine is right for you.
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