Drug Monograph

Aubagio

teriflunomide
Pyrimidine Synthesis Inhibitor (DHODH) · Oral Once-Daily · FDA Boxed Warning
FDA Boxed Warning
Hepatotoxicity and Embryofetal Toxicity

Hepatotoxicity: Clinically significant and potentially life-threatening liver injury, including acute liver failure requiring transplant, has been reported in patients treated with teriflunomide in the post-marketing setting. Concomitant use with other hepatotoxic drugs may increase the risk. Obtain transaminase and bilirubin levels within 6 months before initiation and monitor ALT at least monthly for 6 months after starting therapy.

Embryofetal toxicity: Teriflunomide may cause major birth defects if used during pregnancy. Teratogenicity and embryofetal lethality have been demonstrated in animal reproduction studies at plasma exposures lower than the maximum recommended human dose. Teriflunomide is contraindicated in pregnant women and in females of reproductive potential not using effective contraception. Pregnancy must be excluded before initiation; if pregnancy occurs, discontinue immediately and start an accelerated elimination procedure.

Pharmacokinetic Profile
Median Half-Life
~19 days (14 mg); ~18 days (7 mg)
Metabolism
Primarily hydrolysis (minimal CYP)
Volume of Distribution
11 L (after IV)
Bioavailability
~100% oral
Time to Steady State
~20 weeks
Clinical Information
Drug Class
Pyrimidine synthesis inhibitor (selective, reversible DHODH inhibitor); immunomodulator
Available Strengths
7 mg and 14 mg film-coated tablets
Route
Oral, once daily, with or without food
Renal Adjustment
No adjustment (mild, moderate, or severe)
Hepatic Adjustment
No adjustment in mild–moderate impairment; contraindicated in severe
Pregnancy
Contraindicated
Lactation
Avoid (contraindicated per EMA SmPC); detected in animal milk; insufficient human data
Schedule / Status
Prescription only (Rx); not a controlled substance
Generic Available
Yes (US); originator brand: Aubagio (Sanofi-Genzyme)
Initial U.S. Approval
12 September 2012 (NDA 202992)
Rx

Indications

Teriflunomide is an oral, once-daily immunomodulator approved for the treatment of relapsing forms of multiple sclerosis. It is the principal active metabolite of leflunomide and exerts its effect through selective and reversible inhibition of dihydroorotate dehydrogenase (DHODH), a key mitochondrial enzyme in the de novo synthesis of pyrimidines required by rapidly dividing lymphocytes. Slow-dividing or resting lymphocytes, which rely on the salvage pathway, are largely spared, helping to preserve general immune competence. Teriflunomide was the second oral disease-modifying therapy approved for MS in the United States and remains a moderate-efficacy option in the modern DMT landscape, particularly valued for its convenience, well-characterised long-term safety profile, and broad real-world experience exceeding 100,000 patients and approximately 285,800 patient-years as of 2019.

IndicationApproved PopulationTherapy TypeStatus
Relapsing forms of multiple sclerosis (RMS) — including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive diseaseAdults (FDA, EMA)MonotherapyFDA & EMA Approved
Relapsing-remitting multiple sclerosisPaediatric patients aged 10–17 years (EMA only)MonotherapyEMA Approved (2021)

Teriflunomide is approved as monotherapy and is not indicated for primary progressive multiple sclerosis. The European Commission extended the approval to include children aged 10–17 years with relapsing-remitting MS in 2021 based on the TERIKIDS trial. The FDA has not approved paediatric use; the current US prescribing information explicitly states that effectiveness in patients aged 10–17 was not established in TERIKIDS, and notes that cases of pancreatitis were observed in this paediatric trial. Although the TOPIC study demonstrated significant reduction in conversion to clinically definite MS in patients with a first clinical demyelinating event, the FDA umbrella indication of “relapsing forms” already encompasses clinically isolated syndrome under the 2017 McDonald criteria.

Off-Label Uses

Radiologically isolated syndrome (RIS) — the TERIS randomised trial (n=89) reported a 63% unadjusted risk reduction in time to a first clinical demyelinating event with teriflunomide 14 mg versus placebo over 96 weeks. Evidence quality: moderate (single phase 3 trial; small sample).

Paediatric MS in jurisdictions outside the EU — TERIKIDS missed its primary endpoint (time to relapse) but met key secondary MRI endpoints (T2 lesions reduced 55%, gadolinium-enhancing lesions reduced 75%). EMA-approved for ages 10–17; FDA has not approved this indication. Evidence quality: moderate.

Off-label use should follow shared decision-making and ideally be coordinated through neuroimmunology specialists.

Dose

Dosing

Teriflunomide is administered orally as a single daily tablet. No loading dose, dose titration, or weight-based adjustment is required. Both 7 mg and 14 mg doses are clinically active, but the 14 mg dose has shown more consistent benefit on disability progression in pivotal trials and is the preferred maintenance dose for most patients. Steady-state plasma concentrations are not reached for approximately 20 weeks, and the long terminal half-life (about 18–19 days) has important implications for adverse-event management, drug interactions, and pregnancy planning.

Clinical ScenarioStarting DoseMaintenance DoseMaximum Daily DoseNotes
Relapsing MS — standard adult dosing14 mg PO once daily14 mg/dayPreferred dose; greater effect on confirmed disability progression in pivotal trials
Take with or without food; food has no clinically relevant effect on absorption
Relapsing MS — alternative dose (tolerability concerns)7 mg PO once daily7 mg/dayReasonable option for patients intolerant of 14 mg; both doses reduce annualised relapse rate, but the 7 mg dose did not consistently slow disability progression
Missed doseTake the dose as soon as remembered on the same dayIf close to the next scheduled dose, skip the missed dose and resume the next day
Do not double-dose

Accelerated Elimination Procedure

Teriflunomide undergoes extensive enterohepatic recycling and is eliminated slowly, taking approximately 8 months on average for plasma concentrations to fall below the recommended threshold of 0.02 mg/L (0.02 µg/mL); individual variation may extend this to 2 years. When rapid clearance is needed — suspected drug-induced liver injury, planned pregnancy or unintended pregnancy, severe adverse reaction, switch to another high-efficacy DMT, or overdose — an accelerated elimination procedure is performed.

  • Cholestyramine 8 g orally every 8 hours for 11 days (preferred regimen). If 8 g is not tolerated, 4 g every 8 hours may be used, but the elimination is somewhat less complete.
  • Activated charcoal 50 g orally every 12 hours for 11 days as an alternative when cholestyramine is poorly tolerated or contraindicated.
  • Dosing days do not need to be consecutive unless plasma concentrations need to be lowered rapidly (e.g., toxicity, confirmed pregnancy).
  • Both regimens reduce plasma concentrations by more than 98% over 11 days. Verify two separate plasma concentrations <0.02 mg/L at least 14 days apart before clearing the patient (e.g., for conception or for switching to another therapy with overlapping immunosuppression).
  • Haemodialysis is not effective at removing teriflunomide because of its >99% plasma protein binding.

Special Populations

  • Renal impairment: no dose adjustment required for any degree of impairment, including dialysis-dependent patients. Free fraction may rise modestly in severe impairment but did not require dose change.
  • Mild–moderate hepatic impairment (Child-Pugh A or B): no dose adjustment.
  • Severe hepatic impairment (Child-Pugh C): contraindicated. Pharmacokinetics not evaluated.
  • Elderly (≥65 years): not specifically studied; pivotal trials enrolled patients up to 55 years. Use the standard 14 mg dose with closer monitoring of liver function and infection risk.
  • Pregnancy: contraindicated. Effective contraception is required during therapy and until plasma teriflunomide is verified <0.02 mg/L (either after spontaneous elimination over ~8 months or after an accelerated elimination procedure).
  • Lactation: avoid (contraindicated during breastfeeding per EMA SmPC). Teriflunomide is detected in rat milk; human data are insufficient. The long half-life means infant exposure could be prolonged.
  • Paediatric patients (10–17 years): EMA-approved (2021) at 7 mg or 14 mg once daily based on TERIKIDS; the FDA has not approved paediatric use. Cases of pancreatitis were observed in the TERIKIDS trial.
  • Males planning conception: teriflunomide is detected in human semen, but plasma concentrations in male partners are very low. Risk of male-mediated fetal toxicity is considered low; nevertheless, men wishing to father a child have the option to undergo an accelerated elimination procedure to reduce plasma teriflunomide to <0.02 mg/L before attempting conception.
Clinical Pearl — Switching Practicalities

Because of teriflunomide’s long half-life and its position as a moderate-efficacy DMT, clinicians frequently encounter switching scenarios. When switching to teriflunomide from injectable platform therapies, no washout is needed. When switching from teriflunomide to a higher-efficacy agent (e.g., natalizumab, ocrelizumab, ofatumumab, cladribine, S1P modulators), an accelerated elimination procedure is generally recommended to reduce the risk of additive immunosuppression — even in the absence of a documented adverse interaction. After elimination is verified (plasma <0.02 mg/L confirmed twice, ≥14 days apart), the new DMT can be initiated without further delay.

PK

Pharmacology

Mechanism of Action

Teriflunomide is the principal active metabolite of leflunomide and exerts its therapeutic effect through selective, reversible, non-competitive inhibition of dihydroorotate dehydrogenase (DHODH), a mitochondrial enzyme essential to the de novo synthesis of pyrimidines. Because activated, rapidly proliferating B and T lymphocytes are heavily dependent on de novo pyrimidine synthesis, teriflunomide reduces their expansion and effector function while leaving most other cell populations relatively unaffected. Resting and slow-dividing lymphocytes use the salvage pathway and are not significantly suppressed, helping to preserve baseline immune surveillance.

The clinical consequence in multiple sclerosis is a sustained reduction in the number of activated lymphocytes available to traffic to the central nervous system, fewer new and gadolinium-enhancing MRI lesions, lower annualised relapse rates, and — at the 14 mg dose — slower confirmed disability progression. A mean decrease of approximately 15% in white blood cell count (mainly neutrophils and lymphocytes) and approximately 10% in platelet count develops within the first 6 weeks and stabilises during ongoing therapy; most patients remain within normal laboratory ranges.

ADME Profile

ParameterValueClinical Implication
AbsorptionOral bioavailability approximately 100%; Tmax 1–4 hours; food does not affect absorption to a clinically relevant extent. Linear pharmacokinetics across the dose range of 5–25 mg/day; AUC accumulation ratio at steady state is approximately 30 after repeated 7 or 14 mg dosesTablets may be taken with or without food at any time of day; predictable systemic exposure across the licensed dose range
DistributionVolume of distribution approximately 11 L after a single intravenous dose; plasma protein binding >99% (predominantly albumin); largely confined to plasmaExtensive protein binding contributes to the long residence time and explains why dialysis does not effectively remove the drug
MetabolismPrimary biotransformation is hydrolysis to minor metabolites; secondary pathways include oxidation, N-acetylation, and sulfate conjugation. CYP450 plays a minor role in elimination. Teriflunomide itself is an inhibitor of CYP2C8, BCRP, and OATP1B1/OATP1B3 in vivo, and a weak inducer of CYP1A2Limited cytochrome-mediated drug interactions as a victim; the most clinically relevant pharmacokinetic interactions arise from teriflunomide’s effects on transporters and CYP2C8 (e.g., rosuvastatin, repaglinide)
EliminationMedian terminal half-life approximately 19 days at 14 mg and 18 days at 7 mg; steady state reached in ~20 weeks. Over 21 days, 60.1% of an administered dose is excreted: 37.5% via faeces (primarily as unchanged drug through biliary secretion) and 22.6% via urine (mostly metabolites). Extensive enterohepatic recycling mediated by ABCG2 prolongs the half-life. Without intervention, plasma concentrations take an average of 8 months (up to 2 years in some individuals) to fall below 0.02 mg/LLong half-life means therapeutic effect — and adverse effects — persist for many months after discontinuation; rapid clearance requires the accelerated elimination procedure with cholestyramine or activated charcoal, which reduces concentrations by >98% over 11 days

Teriflunomide is the major circulating moiety detected in plasma after oral administration of the parent drug; minor metabolites are present at concentrations more than 1,000-fold lower than the parent drug. Anti-drug immunogenicity is not a feature, given that teriflunomide is a small molecule rather than a protein.

SE

Side Effects

The safety profile of teriflunomide is well-characterised across more than 2,000 patients in placebo-controlled trials and over 285,800 patient-years of real-world exposure. Most adverse reactions are mild to moderate, occur early in therapy, and are self-limited. Frequencies below are drawn primarily from FDA prescribing information Table 1 (pooled placebo-controlled studies of approximately 2,047 teriflunomide-treated patients), the EMA Summary of Product Characteristics, and the long-term TEMSO and TOWER extension studies.

≥10% Very Common — Adverse Reactions in Pooled Placebo-Controlled Trials
Adverse EffectIncidence (14 mg / 7 mg / placebo)Clinical Note
Headache16% / 18% / 15%Usually mild; standard analgesics and reassurance are typically sufficient. The placebo rate of 15% is also high — much of this is background
ALT increased15% / 13% / 9%Mostly <3 × ULN; transient and often resolves with continued therapy. ALT >3 × ULN occurred in 6.2% (14 mg), 5.8% (7 mg), and 3.8% (placebo) of patients; half normalised without discontinuation
Diarrhoea14% / 13% / 8%Generally mild to moderate; usually self-limited within the first few weeks. Symptomatic management is sufficient in most cases
Alopecia (hair thinning / decreased hair density)13% / 10% / 5%Median onset 99 days; usually mild–moderate, reversible, and improves while remaining on therapy. Important early counselling point because of cosmetic concern
Nausea11% / 8% / 7%Mild to moderate; typically resolves with continued therapy. Taking with food may improve tolerability
Mild neutropenia (lab finding: neutrophils <1.5 × 10⁹/L)16% / 12% / 7%Lab abnormality, not a clinical AE; mean WBC drop of ~15% develops in the first 6 weeks and stabilises. Severe neutropenia is rare
Mild lymphopenia (lab finding: lymphocytes <0.8 × 10⁹/L)12% / 10% / placebo not specifiedLab abnormality; mean lymphocyte count typically remains around 1.5 × 10⁹/L. Severe lymphopenia is uncommon
Mild hypophosphataemia (lab finding: phosphorus ≥0.6 mmol/L)18% (pooled teriflunomide) / 7% placeboLab abnormality; clinically asymptomatic in essentially all patients. No serum phosphorus levels <0.3 mmol/L observed in trials
1–10% Common
Adverse EffectIncidence (14 mg / placebo)Clinical Note
Hypertension4.3% / 1.8%Mean systolic BP rise +2.7 mmHg; mean diastolic +1.9 mmHg. Usually responsive to lifestyle measures or standard antihypertensive therapy
Peripheral neuropathy (NCS-confirmed, pooled placebo-controlled trials)1.9% / 0.4%Often improves after discontinuation but may persist; consider nerve conduction studies if suspected. Discontinuation usually warranted if confirmed
Influenza, upper and lower respiratory tract infections, urinary tract infection (per EMA SmPC: ≥1/100 to <1/10)Common (1–10%)Includes nasopharyngitis, bronchitis, sinusitis, pharyngitis, and cystitis. Mostly viral and self-limited; encourage seasonal vaccination
Paresthesia, sciatica, carpal tunnel syndrome (per EMA SmPC)Common (1–10%)Distinguish paresthesia from a possible MS relapse; monitor for evolving peripheral neuropathy
Acne, rashCommon (1–10%)Usually mild and amenable to standard topical therapy
Arthralgia, myalgia, musculoskeletal pain, back painCommon (1–10%)Typically mild; standard analgesics
Anxiety, palpitations, vomiting, abdominal pain, toothache, weight decreaseCommon (1–10%)Per EMA SmPC; usually mild and self-limited
GGT and AST increased, blood creatine phosphokinase increasedCommon (1–10%)Lab findings; investigate clinically significant elevations; CPK rises rarely indicate myositis
Pollakiuria, menorrhagiaCommon (1–10%)Per EMA SmPC; symptomatic management
Serious Serious Adverse Effects (regardless of frequency)
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Acute liver failure / severe hepatotoxicity (boxed warning)Rare; post-marketing reports of cases requiring transplantAny time, but the highest-risk monitoring window is the first 6 monthsDiscontinue immediately; start accelerated elimination with cholestyramine; refer to hepatology; investigate competing causes
Fetal harm (boxed warning)Class effect based on animal dataFirst-trimester exposure of greatest concernConfirm pregnancy with quantitative β-hCG; discontinue immediately; perform accelerated elimination; refer to maternal-fetal medicine; report to the Aubagio Pregnancy Registry (1-800-745-4447, option 2)
Bone marrow suppression (severe leukopenia, thrombocytopenia, pancytopenia)Rare (post-marketing)Variable; most often within the first monthsDiscontinue therapy; perform accelerated elimination; obtain haematology input
Serious infections (bacterial, viral, opportunistic)14 mg 2.7%; 7 mg 2.2%; placebo 2.2% (no overall increase in pooled trials)Any time during therapyHold further dosing during severe infection; consider accelerated elimination if infection is opportunistic or fails to respond
Tuberculosis reactivationRareVariableScreen for latent TB before initiation; treat latent TB before starting; coordinate with infectious diseases for active disease
Severe skin reactions — Stevens–Johnson syndrome, toxic epidermal necrolysis (including a fatal case), DRESS (including a fatal case)Rare (post-marketing)Days to weeks after initiationDiscontinue immediately; perform accelerated elimination; refer for urgent dermatology and inpatient care if mucosal involvement or systemic features
Hypersensitivity / anaphylaxis / angioedemaRareMinutes to daysDiscontinue permanently; perform accelerated elimination; manage acute reaction with epinephrine, antihistamines, and corticosteroids as indicated
Interstitial lung disease (acute interstitial pneumonitis)Rare (post-marketing; class effect with leflunomide)Variable, may be acute; can be fatalInvestigate new or worsening dyspnoea/cough with chest imaging; discontinue if confirmed; perform accelerated elimination
Hyperkalaemia and acute uric acid nephropathy with transient acute renal failureUncommon (per FDA PI; some elevations transient)VariableMonitor electrolytes and renal function as clinically indicated; manage acutely; consider accelerated elimination
Hypertensive crisisUncommonVariableManage acutely; consider continuation of teriflunomide with antihypertensive therapy if no other contributing cause
Severe peripheral neuropathy (within the broader 1.9% NCS-confirmed neuropathy rate)RareVariableDiscontinue; perform accelerated elimination if symptoms are progressive or disabling; consult neurology
Pancreatitis (paediatric trial finding)Reported in TERIKIDSVariableIf pancreatitis is suspected, discontinue teriflunomide and start accelerated elimination per FDA labelling
Discontinuation Discontinuation Rates
Pooled placebo-controlled studies
12.5% / 11.2% vs 7.5% placebo
14 mg / 7 mg / placebo: AE-related discontinuation. Most common driver: ALT elevation
Long-term TEMSO extension (~9 yr)
~11% cumulative AE-related
Most common drivers: ALT elevation, hair thinning, GI intolerance
Reason for DiscontinuationIncidenceContext
ALT elevation7 mg 3.3%; 14 mg 2.6%; placebo 2.3%Most common reason for treatment discontinuation in pivotal trials. Most events are reversible after discontinuation and accelerated elimination
Hair thinning / alopecia (patient choice)~1–2%Cosmetic concerns; counselling about reversibility may improve persistence
Diarrhoea or nausea~1–2%Usually resolves with continued therapy; rarely warrants discontinuation alone
Pregnancy planning~1–2%Long half-life requires either an 8-month spontaneous washout or an accelerated elimination procedure
Lack of efficacy / breakthrough disease activity~3–5% over long-term follow-upTriggers escalation to higher-efficacy DMTs, often with accelerated elimination during the switch
Other adverse events / patient choice~3–5%Includes peripheral neuropathy, hypertension, infections
Management Priority — Liver Monitoring

Hepatotoxicity is the most clinically important risk. Obtain transaminases and bilirubin within the 6 months before initiation, then check ALT at least monthly for the first 6 months of therapy, and every 6–12 weeks thereafter (or sooner if symptoms develop). If ALT exceeds 3 × ULN on a confirmed repeat measurement, discontinue teriflunomide and start an accelerated elimination procedure. Monitor LFTs weekly until normalisation. If liver injury is judged unrelated to teriflunomide after evaluation, resumption may be considered.

Int

Drug Interactions

Teriflunomide is metabolised primarily by hydrolysis with minor CYP involvement, so it is a “victim” in relatively few interactions. As a “perpetrator,” it inhibits CYP2C8, BCRP, OATP1B1/1B3, and OAT3, and weakly induces CYP1A2. The most clinically important interactions are pharmacodynamic (additive immunosuppression, hepatotoxicity), the absolute contraindication with leflunomide, and the substrate-level effects on rosuvastatin, repaglinide, and warfarin.

Contraindicated Leflunomide
MechanismLeflunomide is a prodrug that converts almost entirely into teriflunomide; combined use produces additive plasma exposure and toxicity
EffectMarkedly elevated teriflunomide concentrations and risk of severe hepatotoxicity, cytopenia, and infection
ManagementDo not coadminister; choose only one agent
FDA PI
Major Live attenuated vaccines (MMR, varicella, yellow fever, oral polio, BCG, intranasal influenza)
MechanismLymphocyte suppression with theoretical risk of vaccine-strain replication
EffectRisk of vaccine-strain infection; reduced antibody response
ManagementAvoid during therapy and until plasma teriflunomide is <0.02 mg/L; complete required live vaccines before initiation
FDA PI
Major Other hepatotoxic drugs (e.g., methotrexate, isoniazid, valproate, certain azoles)
MechanismAdditive hepatocellular injury
EffectIncreased risk of clinically significant transaminitis or acute liver failure
ManagementAvoid where possible; if combination is unavoidable, monitor LFTs more frequently
FDA PI
Major Other immunosuppressants and high-efficacy DMTs (azathioprine, mycophenolate, cladribine, anti-CD20 agents, S1P modulators, natalizumab)
MechanismAdditive lymphocyte suppression
EffectIncreased risk of opportunistic infection and persistent lymphopenia
ManagementAvoid concurrent use; when switching, perform an accelerated elimination procedure and verify plasma <0.02 mg/L before initiating the next DMT
FDA PI
Moderate Rosuvastatin
MechanismTeriflunomide inhibits BCRP and OATP1B1/1B3 transporters that mediate rosuvastatin disposition
EffectMean rosuvastatin Cmax increased 2.65-fold and AUC 2.51-fold; increased risk of myopathy and rhabdomyolysis
ManagementDo not exceed rosuvastatin 10 mg once daily during teriflunomide therapy; monitor for muscle symptoms
FDA PI
Moderate CYP2C8 substrates (e.g., repaglinide, paclitaxel, pioglitazone, rosiglitazone)
MechanismTeriflunomide is an in vivo inhibitor of CYP2C8
EffectIncreased substrate exposure; e.g., repaglinide Cmax increased 1.7-fold and AUC 2.4-fold
ManagementMonitor for substrate toxicity and adjust dose as required
FDA PI
Moderate Other BCRP / OATP1B1/1B3 substrates (e.g., methotrexate, atorvastatin, simvastatin, pravastatin, mitoxantrone)
MechanismTeriflunomide inhibits these hepatic uptake and efflux transporters
EffectPotential for increased substrate exposure and toxicity (e.g., statin-related myopathy)
ManagementUse the lowest effective statin dose; monitor for myopathy and other substrate-specific toxicities
FDA PI
Moderate Warfarin
MechanismMechanism not fully elucidated; teriflunomide does not affect S-warfarin (CYP2C9) PK
EffectApproximately 25% decrease in peak INR observed in healthy volunteers — INR may fall
ManagementMonitor INR more frequently when starting, stopping, or dose-adjusting teriflunomide
FDA PI
Moderate Combined oral contraceptives
MechanismTeriflunomide modestly increases hormonal exposure (transporter inhibition)
EffectMean ethinylestradiol Cmax up 1.58-fold, AUC up 1.54-fold; levonorgestrel Cmax up 1.33-fold, AUC up 1.41-fold. Contraceptive efficacy is preserved
ManagementContinue effective contraception (no contraceptive failure expected); FDA labelling advises consideration of OC type or dose given the increased oestrogen exposure
FDA PI
Moderate CYP1A2 substrates (e.g., caffeine, alosetron, duloxetine, theophylline, tizanidine)
MechanismTeriflunomide is a weak in vivo inducer of CYP1A2
EffectReduced substrate exposure: caffeine Cmax decreased ~18% and AUC decreased ~55% with repeated teriflunomide dosing
ManagementMonitor for reduced effect of narrow-therapeutic-index CYP1A2 substrates and adjust dose if clinically warranted
FDA PI
Moderate OAT3 substrates (e.g., cefaclor, benzylpenicillin, indomethacin, ketoprofen, furosemide, methotrexate)
MechanismTeriflunomide inhibits renal OAT3 transport
EffectIncreased exposure of substrate
ManagementUse with caution; monitor for substrate toxicity
FDA PI
Mon

Monitoring

Monitoring centres on the boxed warnings — hepatotoxicity and embryofetal toxicity — and on a structured pre-treatment workup that screens for infection, blood pressure, pregnancy, and baseline haematology. Most adverse events declare themselves within the first 6 months, so the monitoring schedule is most intensive during this window.

  • ALT (and AST, ALP, bilirubin) Within 6 mo before initiation, then monthly × 6 months, then periodically (3–6-monthly) thereafter
    Routine
    Cornerstone of safety monitoring (boxed warning). If ALT >3 × ULN is confirmed on repeat testing, discontinue teriflunomide and initiate accelerated elimination. Investigate symptoms of hepatic dysfunction (unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, jaundice, dark urine) urgently regardless of recent normal LFTs.
  • Pregnancy test Before initiation in all patients of reproductive potential; rapid retest if any clinical suspicion
    Routine
    Confirm a negative pregnancy test before starting therapy. Counsel about effective contraception during therapy and until plasma teriflunomide is verified <0.02 mg/L after discontinuation. Refer all suspected pregnancies for accelerated elimination and to maternal-fetal medicine; report to the Aubagio Pregnancy Registry (1-800-745-4447, option 2).
  • Complete blood count with differential Within 6 months before initiation, then periodically based on signs and symptoms of infection or marrow suppression
    Routine
    Mild reductions in lymphocytes and neutrophils are expected. Severe cytopenia is rare but warrants discontinuation and accelerated elimination.
  • Blood pressure Baseline; periodically thereafter
    Routine
    Hypertension occurs in 4.3% of 14 mg patients vs 1.8% on placebo. Manage with lifestyle measures or standard antihypertensive therapy; teriflunomide rarely requires discontinuation for hypertension alone.
  • Tuberculosis screening Before initiation
    Routine
    Tuberculin skin test or interferon-gamma release assay; treat latent tuberculosis before starting therapy in line with local infection-control guidance.
  • Hepatitis B and C screening Before initiation
    Routine
    Identify patients with chronic viral hepatitis who may require hepatology input and antiviral prophylaxis to limit hepatotoxicity risk.
  • Vaccination review Before initiation; annual seasonal vaccines on therapy
    Routine
    Complete required live vaccines before starting; inactivated vaccines (influenza, pneumococcal, COVID-19, hepatitis B) generate adequate responses on therapy and are recommended.
  • Symptom review Every visit; safety-net all patients between visits
    Routine
    Specifically ask about peripheral neuropathy symptoms (numbness, tingling, weakness), dyspnoea or new cough (interstitial lung disease), unexplained fever or skin rash, and new GI or hepatic symptoms.
  • Brain MRI Annually or per institutional MS protocol
    Routine
    Assess MS disease activity (new T2 or gadolinium-enhancing lesions). Breakthrough activity may indicate need for escalation to a higher-efficacy DMT.
  • Plasma teriflunomide concentration After accelerated elimination procedure or when clearance must be verified
    Trigger-based
    Confirm two separate plasma concentrations <0.02 mg/L at least 14 days apart before allowing pregnancy or before initiating another DMT with overlapping immunosuppression.
  • Nerve conduction studies If new sensory or motor symptoms suggest peripheral neuropathy
    Trigger-based
    Confirmed peripheral neuropathy may warrant discontinuation; symptoms can persist after stopping therapy and may be slower to resolve without accelerated elimination.
  • Chest imaging / pulmonary review If new dyspnoea, persistent cough, or unexplained hypoxia
    Trigger-based
    Investigate promptly for interstitial lung disease (a leflunomide-class effect); discontinue teriflunomide and start accelerated elimination if confirmed.
  • Pancreatic enzymes (lipase, amylase) If new severe abdominal pain (especially in paediatric patients)
    Trigger-based
    Pancreatitis was observed in the TERIKIDS paediatric trial. Per current FDA labelling, if pancreatitis is suspected, discontinue teriflunomide and start an accelerated elimination procedure.
CI

Contraindications & Cautions

Absolute Contraindications

  • Severe hepatic impairment (Child-Pugh C). Pharmacokinetics not evaluated and risk of further hepatotoxicity is unacceptable.
  • Pregnancy. Confirm a negative pregnancy test before initiation; teriflunomide is teratogenic and embryolethal in animals at exposures lower than the maximum recommended human dose.
  • Females of reproductive potential not using effective contraception. Effective contraception must be in place before therapy begins and continued until plasma teriflunomide is verified <0.02 mg/L after discontinuation.
  • Hypersensitivity to teriflunomide, leflunomide, or any inactive ingredient. Reactions have included anaphylaxis, angioedema, and serious skin reactions.
  • Coadministration with leflunomide. Combined exposure produces additive teriflunomide toxicity.

Relative Contraindications (Specialist Input Recommended)

  • Pre-existing acute or chronic liver disease, or baseline ALT >2 × ULN — generally avoid; if unavoidable, hepatology co-management and intensified LFT monitoring.
  • Severe immunodeficiency, severe bone marrow disease, or severe uncontrolled infection — defer therapy until resolved or stabilised.
  • Active or untreated latent tuberculosis — treat latent TB before initiation.
  • Active hepatitis B or C — manage in conjunction with hepatology before initiation.
  • Significant bone marrow suppression or recent treatment with myelosuppressive agents — avoid until haematology recovers.
  • Concomitant use of strong hepatotoxins — avoid where possible; if unavoidable, intensify LFT monitoring.

Use with Caution

  • Pre-existing peripheral neuropathy — monitor for worsening; consider alternative DMT.
  • Significant cardiovascular disease or pre-existing hypertension — control blood pressure before initiation and monitor on therapy.
  • Pre-existing interstitial lung disease — increased risk of recurrence or worsening (class effect with leflunomide).
  • History of pancreatitis — consider given the paediatric TERIKIDS finding; monitor for new abdominal symptoms.
  • Older adults (≥65 years) — limited trial data; use with closer monitoring.
  • Patients with poor treatment adherence or unable to attend monthly LFT monitoring — adherence to safety monitoring is essential given the boxed warning for hepatotoxicity.
FDA Boxed Warning Hepatotoxicity

Clinically significant and potentially life-threatening liver injury, including acute liver failure requiring transplant, has been reported in patients treated with teriflunomide in the post-marketing setting. A similar risk was identified earlier with leflunomide because both drugs achieve similar plasma teriflunomide concentrations. Concomitant hepatotoxic drugs increase the risk. Obtain transaminases and bilirubin within 6 months before initiation and monitor ALT at least monthly for 6 months after starting therapy. Discontinue and start accelerated elimination if ALT >3 × ULN is confirmed.

FDA Boxed Warning Embryofetal Toxicity

Teriflunomide may cause major birth defects if used during pregnancy. Animal reproduction studies in rats and rabbits show teratogenicity and embryolethality at plasma teriflunomide exposures lower than the maximum recommended human dose of 14 mg/day. Teriflunomide is contraindicated in pregnant women and in females of reproductive potential not using effective contraception. Exclude pregnancy before initiation; if pregnancy occurs during therapy, discontinue immediately and perform an accelerated elimination procedure.

FDA Warnings and Precautions Bone Marrow Effects, Infection Risk, Skin Reactions, and Pancreatitis (Paediatric Trial)

Mild reductions in white blood cell count and platelets occur during therapy; rarely, severe pancytopenia, agranulocytosis, or thrombocytopenia have been reported. Serious infections, including tuberculosis reactivation and opportunistic infections, may occur. Stevens–Johnson syndrome, toxic epidermal necrolysis (including a fatal case), and DRESS (including a fatal case) have been reported in the post-marketing setting. Cases of pancreatitis were observed in the paediatric clinical trial (TERIKIDS); discontinue teriflunomide and start an accelerated elimination procedure if pancreatitis is suspected.

Pt

Patient Counselling

Purpose of Therapy

Teriflunomide is a once-daily tablet that lowers the activity of certain immune cells (lymphocytes) that contribute to multiple sclerosis. It reduces relapses and slows the development of new MRI lesions; the 14 mg dose also slows the build-up of disability. It does not cure MS, and it may take several months to reach its full effect.

How to Take

Swallow one tablet (7 mg or 14 mg) by mouth once a day. The tablet may be taken with or without food, at any time of day, but consistency helps with adherence. Do not stop teriflunomide without speaking to a clinician — because the medication remains in the body for up to 8 months (occasionally up to 2 years), sudden discontinuation does not provide rapid clearance. If a more rapid removal is needed (for example, for pregnancy planning, suspected liver injury, or before starting another medication), a clinician will prescribe an “accelerated elimination procedure” using cholestyramine or activated charcoal for 11 days.

Liver health
Tell patient Liver enzymes will be checked before starting and every month for the first 6 months. Mild rises are common and usually settle. Avoid heavy alcohol use and tell every clinician you take teriflunomide before they prescribe new medication, as some drugs combine badly with it.
Call prescriber Unexplained nausea, vomiting, loss of appetite, severe tiredness, abdominal pain (especially upper right), yellowing of the skin or eyes, or dark urine — contact the MS team the same day.
Pregnancy and contraception
Tell patient Teriflunomide can cause severe birth defects. Effective contraception is essential during therapy and afterwards until a clinician confirms (with a blood test) that the medication has cleared. Plan any pregnancy in advance with the MS team; a special 11-day “washout” procedure clears the drug far faster than waiting naturally.
Call prescriber If pregnancy is planned, suspected, or confirmed at any point during therapy or in the months after stopping. Do not wait for the next routine appointment. Pregnancies on teriflunomide should also be reported to the manufacturer’s pregnancy registry.
Hair thinning
Tell patient About 13 in 100 patients on the 14 mg dose notice some hair thinning, usually starting in the first few months (median onset around 99 days). It is almost always mild, reversible, and improves while continuing therapy. Gentle hair care and avoiding harsh treatments help.
Call prescriber If thinning is distressing or progressing rather than improving — alternative DMTs are available.
Stomach and bowel symptoms
Tell patient Diarrhoea and nausea are common in the first weeks and usually settle. Taking the tablet with food may help. Stay well hydrated and use simple anti-diarrhoeal measures if needed.
Call prescriber Severe or bloody diarrhoea, persistent vomiting, dehydration, weight loss, or severe upper abdominal pain that radiates to the back (which could suggest pancreatitis).
Infection risk
Tell patient Teriflunomide modestly weakens the immune system. Most patients only have a slight increase in routine colds and urinary tract infections. Hand hygiene, prompt dental care, and seasonal vaccines (non-live) help reduce risk. Live vaccines (such as MMR or yellow fever) should be avoided during therapy.
Call prescriber Fever above 38.0 °C, productive cough lasting more than a few days, painful red skin patches, persistent diarrhoea, or any unusually severe or slow-resolving infection.
Blood pressure
Tell patient A small number of patients develop new or worsening high blood pressure. Periodic checks are needed; most cases are easily managed with lifestyle changes or standard medication.
Call prescriber Severe headaches, visual changes, or repeatedly high home blood pressure readings.
Numbness, tingling, or weakness
Tell patient Some patients develop a problem with the nerves outside the brain (peripheral neuropathy), causing numbness, tingling, or weakness in the hands or feet. This is different from MS attacks and may need specific testing.
Call prescriber New persistent tingling, numbness, weakness, or balance problems that do not feel like a usual MS relapse.
Skin or breathing reactions
Tell patient Rare but serious reactions involving widespread rash, blisters, mouth sores, or difficulty breathing have been reported. These need immediate evaluation.
Call prescriber Severe rash, peeling skin, blistering, mouth or eye sores, swelling of the face, lips, or tongue, wheezing, or progressive shortness of breath — call emergency services immediately.
Ref

Sources

Regulatory (PI / SmPC)
  1. Sanofi-Genzyme. AUBAGIO (teriflunomide) tablets — Full Prescribing Information. https://products.sanofi.us/aubagio/aubagio.pdf Primary US labelling; authoritative source for indications, dosing, boxed warnings, contraindications, drug interactions, monitoring, and adverse reaction tables (Table 1).
  2. US Food and Drug Administration. AUBAGIO (teriflunomide) — Approved Labelling, NDA 202992 (s017). 2024. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/202992s017lbl.pdf Most recent FDA-approved label revision; reflects the current wording of the boxed warning (HEPATOTOXICITY and EMBRYOFETAL TOXICITY) and the paediatric pancreatitis precaution.
  3. European Medicines Agency. Aubagio: EPAR — Product Information. https://www.ema.europa.eu/en/documents/product-information/aubagio-epar-product-information_en.pdf European Summary of Product Characteristics; primary source for the EMA paediatric (10–17 years) approval and the EMA frequency tables for adverse reactions.
  4. National Library of Medicine. AUBAGIO — DailyMed Drug Label. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4650d12c-b9c8-4525-b07f-a2d773eca155 Continuously updated repository of the latest FDA-approved labelling text for clinician reference.
Key Clinical Trials
  1. O’Connor P, Wolinsky JS, Confavreux C, et al. Randomized trial of oral teriflunomide for relapsing multiple sclerosis. N Engl J Med. 2011;365(14):1293–1303. https://doi.org/10.1056/NEJMoa1014656 TEMSO pivotal phase 3 trial (n=1,088) establishing efficacy of teriflunomide 7 mg and 14 mg vs placebo over 108 weeks; primary source for ARR (0.37 vs 0.54), confirmed disability progression, and adverse-event rates.
  2. Confavreux C, O’Connor P, Comi G, et al. Oral teriflunomide for patients with relapsing multiple sclerosis (TOWER): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Neurol. 2014;13(3):247–256. https://doi.org/10.1016/S1474-4422(13)70308-9 Second pivotal phase 3 trial confirming reduction in ARR (36% relative reduction at 14 mg vs placebo) and disability progression in 1,169 patients.
  3. Vermersch P, Czlonkowska A, Grimaldi LM, et al. Teriflunomide versus subcutaneous interferon beta-1a in patients with relapsing multiple sclerosis: a randomised, controlled phase 3 trial. Mult Scler. 2014;20(6):705–716. https://doi.org/10.1177/1352458513507821 TENERE active-comparator trial; teriflunomide 14 mg achieved annualised relapse rate similar to subcutaneous IFN beta-1a, supporting its place as a moderate-efficacy oral alternative.
  4. Miller AE, Wolinsky JS, Kappos L, et al. Oral teriflunomide for patients with a first clinical episode suggestive of multiple sclerosis (TOPIC): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Neurol. 2014;13(10):977–986. https://doi.org/10.1016/S1474-4422(14)70191-7 Phase 3 trial in 618 clinically isolated syndrome patients; demonstrated reduction in conversion to clinically definite MS.
  5. O’Connor P, Comi G, Freedman MS, et al. Long-term safety and efficacy of teriflunomide: nine-year follow-up of the randomized TEMSO study. Neurology. 2016;86(10):920–930. https://doi.org/10.1212/WNL.0000000000002441 Long-term TEMSO extension; supports cumulative AE-related discontinuation rates and durable efficacy on relapses and MRI activity.
  6. Comi G, Freedman MS, Kappos L, et al. Pooled safety and tolerability data from four placebo-controlled teriflunomide studies and extensions. Mult Scler Relat Disord. 2016;5:97–104. PMID 26856952. Pooled safety analysis from phase 2, TEMSO, TOWER, and TOPIC; primary source for very common adverse events at incidence ≥10% and ≥2% above placebo: ALT increase, headache, diarrhoea, hair thinning, nausea.
  7. Chitnis T, Banwell B, Kappos L, et al. Safety and efficacy of teriflunomide in paediatric multiple sclerosis (TERIKIDS): a multicentre, double-blind, phase 3, randomised, placebo-controlled trial. Lancet Neurol. 2021;20(12):1001–1011. https://doi.org/10.1016/S1474-4422(21)00364-1 Phase 3 paediatric trial (n=166; 109 teriflunomide, 57 placebo) supporting EMA paediatric approval; primary endpoint not met but T2 lesion burden reduced 55% and gadolinium-enhancing lesions reduced 75%.
  8. Lebrun-Frénay C, Siva A, Sormani MP, et al. Teriflunomide and time to clinical multiple sclerosis in patients with radiologically isolated syndrome: the TERIS randomized clinical trial. JAMA Neurol. 2023;80(10):1080–1088. https://doi.org/10.1001/jamaneurol.2023.2815 Phase 3 trial (n=89) in radiologically isolated syndrome; teriflunomide 14 mg reduced the risk of a first clinical demyelinating event by 63% (unadjusted) versus placebo.
Pharmacokinetics & Mechanism
  1. Bar-Or A, Pachner A, Menguy-Vacheron F, Kaplan J, Wiendl H. Teriflunomide and its mechanism of action in multiple sclerosis. Drugs. 2014;74(6):659–674. https://doi.org/10.1007/s40265-014-0212-x Comprehensive mechanism review; underpins the DHODH inhibition / pyrimidine de novo synthesis description in the Pharmacology section.
  2. National Institutes of Health, LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Teriflunomide. https://www.ncbi.nlm.nih.gov/books/NBK548525/ Authoritative summary of teriflunomide hepatotoxicity, supporting the boxed warning narrative and monitoring recommendations.
Guidelines
  1. Rae-Grant A, Day GS, Marrie RA, et al. Practice guideline recommendations summary: disease-modifying therapies for adults with multiple sclerosis. Neurology. 2018;90(17):777–788. https://doi.org/10.1212/WNL.0000000000005347 American Academy of Neurology guideline (reaffirmed 2024) positioning teriflunomide among DMT options for active relapsing MS.
  2. Montalban X, Gold R, Thompson AJ, et al. ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis. Eur J Neurol. 2018;25(2):215–237. https://doi.org/10.1111/ene.13536 European treatment guideline informing positioning of teriflunomide as a moderate-efficacy first-line oral DMT.
  3. Vukusic S, Carra-Dalliere C, Ciron J, et al. Pregnancy and multiple sclerosis: 2022 recommendations from the French multiple sclerosis society. Mult Scler J. 2023;29(1):11–36. https://doi.org/10.1177/13524585221129472 Practical guidance on managing DMTs around conception and lactation; informs the contraindications, monitoring, and counselling sections.