Dimethyl Fumarate Pharmathen

Disease-modifying therapy for relapsing-remitting multiple sclerosis

Prescription Only (Rx) ATC: L04AX07 Immunomodulatory Agent
Active Ingredient
Dimethyl fumarate
Available Forms
Gastro-resistant hard capsules
Strengths
120 mg, 240 mg
Administration
Oral
Medically reviewed by iMedic Medical Team
Evidence Level 1A

Dimethyl Fumarate Pharmathen is a disease-modifying oral medication used to treat adults with relapsing-remitting multiple sclerosis (RRMS). It works by activating the Nrf2 antioxidant pathway and modulating the immune response, helping to reduce the frequency of relapses and slow the progression of disability. Available as gastro-resistant capsules in 120 mg and 240 mg strengths, it is taken twice daily with food.

Quick Facts

Active Ingredient
Dimethyl fumarate
Drug Class
Immunomodulatory
ATC Code
L04AX07
Common Uses
Relapsing MS
Available Forms
Capsules
Prescription Status
Rx Only

Key Takeaways

  • Dimethyl Fumarate Pharmathen is an oral disease-modifying therapy (DMT) approved for relapsing-remitting multiple sclerosis in adults, reducing relapse rates by approximately 44-53% compared to placebo.
  • Treatment starts at 120 mg twice daily for 7 days, then increases to the maintenance dose of 240 mg twice daily; capsules should be taken with food to reduce gastrointestinal side effects.
  • Regular blood monitoring (complete blood count including lymphocytes) is essential before starting and every 3 months during treatment to detect lymphopenia, which increases the risk of progressive multifocal leukoencephalopathy (PML).
  • The most common side effects are flushing and gastrointestinal symptoms, which typically improve within the first 2-3 months of treatment; taking aspirin 30 minutes before the dose can help manage flushing.
  • Liver function tests and renal function should be assessed before starting treatment; dimethyl fumarate should not be used during pregnancy and effective contraception is recommended for women of childbearing potential.

What Is Dimethyl Fumarate Pharmathen and What Is It Used For?

Quick Answer: Dimethyl Fumarate Pharmathen is an oral immunomodulatory medicine used to treat relapsing-remitting multiple sclerosis (RRMS) in adults. It helps reduce the number and severity of MS relapses and slows the accumulation of physical disability.

Dimethyl Fumarate Pharmathen contains the active substance dimethyl fumarate, which belongs to the class of immunomodulatory agents used as disease-modifying therapies (DMTs) for multiple sclerosis. It is a generic medicine that contains the same active substance and works in the same way as the reference medicine Tecfidera, which has been authorised in the European Union since 2014.

Multiple sclerosis is a chronic autoimmune disease of the central nervous system in which the body's immune system mistakenly attacks the protective myelin sheath surrounding nerve fibres in the brain and spinal cord. This process, known as demyelination, disrupts normal nerve signal transmission and leads to a wide range of neurological symptoms including visual disturbances, muscle weakness, fatigue, numbness, balance problems, and cognitive difficulties.

In relapsing-remitting MS, the most common form of the disease affecting approximately 85% of people diagnosed with MS, patients experience clearly defined episodes of neurological deterioration (relapses) followed by periods of partial or complete recovery (remissions). Over time, however, incomplete recovery from relapses can lead to progressive accumulation of disability.

Dimethyl fumarate works through a unique dual mechanism of action. Its primary mechanism involves activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional pathway, a critical cellular defence system against oxidative stress. By upregulating Nrf2, dimethyl fumarate enhances the production of antioxidant enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1), which protect neurons and oligodendrocytes from oxidative damage. Additionally, dimethyl fumarate exerts immunomodulatory effects by promoting a shift from pro-inflammatory Th1 and Th17 immune responses to anti-inflammatory Th2 responses, and by reducing the activation and proliferation of T cells and B cells that drive the autoimmune attack on myelin.

The clinical efficacy of dimethyl fumarate has been demonstrated in two pivotal Phase III clinical trials (DEFINE and CONFIRM), which together enrolled over 2,600 patients with RRMS. In these studies, dimethyl fumarate 240 mg twice daily significantly reduced the annualised relapse rate by 44-53% compared to placebo, and reduced the risk of 12-week confirmed disability progression by 32-38%. MRI outcomes also showed significant reductions in the number of new or enlarging T2-hyperintense lesions and gadolinium-enhancing lesions, indicating reduced disease activity in the central nervous system.

Approved Indication Dimethyl Fumarate Pharmathen is approved by the European Medicines Agency (EMA) for the treatment of adult patients with relapsing-remitting multiple sclerosis. It is available in the EU as a generic medicine and is used as a first-line or second-line disease-modifying therapy depending on individual patient characteristics and disease activity.

What Should You Know Before Taking Dimethyl Fumarate Pharmathen?

Quick Answer: Before starting dimethyl fumarate, your doctor will perform blood tests (complete blood count, liver function, renal function) and may order a baseline MRI. The medicine is contraindicated in patients with known hypersensitivity to dimethyl fumarate or any excipients. Special caution is needed in patients with severe gastrointestinal disease, low lymphocyte counts, or liver impairment.

Contraindications

Dimethyl Fumarate Pharmathen must not be used if you are allergic (hypersensitive) to dimethyl fumarate or any of the other ingredients in the capsule. You should inform your doctor about all known allergies before starting treatment. The medicine should not be initiated in patients with severe active gastrointestinal disease, as the gastro-resistant capsules may exacerbate symptoms.

Due to its immunomodulatory mechanism, dimethyl fumarate should not be used in combination with other immunosuppressive therapies or immunomodulatory agents, unless the benefits clearly outweigh the risks under specialist supervision. The concurrent use of anti-neoplastic or immunosuppressive therapies increases the risk of infection, including opportunistic infections such as progressive multifocal leukoencephalopathy (PML).

Warnings and Precautions

Before prescribing dimethyl fumarate, your physician will order a complete blood count (CBC) including a differential white blood cell count and lymphocyte count. A recent MRI scan (typically within 3 months) should be available as a baseline reference. Liver function tests (ALT, AST, bilirubin) and renal function tests (creatinine, eGFR) should also be performed before initiation of treatment.

Lymphopenia and PML risk: Dimethyl fumarate can cause a decrease in lymphocyte counts (lymphopenia), which typically occurs within the first year of treatment and may persist. In clinical trials, approximately 6% of patients treated with dimethyl fumarate experienced lymphocyte counts below 0.5 x 109/L (grade 3 lymphopenia). Cases of progressive multifocal leukoencephalopathy (PML) have been reported in patients with severe and prolonged lymphopenia (lymphocyte counts below 0.5 x 109/L for more than 6 months). PML is a rare but serious viral infection of the brain caused by the John Cunningham (JC) virus that can lead to severe disability or death.

Complete blood counts including lymphocyte counts must be monitored before starting treatment, every 3 months during treatment, and as clinically indicated thereafter. If lymphocyte counts fall below 0.5 x 109/L and persist for more than 6 months, treatment interruption should be considered. The benefit-risk balance must be carefully reassessed in patients with persistent moderate lymphopenia (0.5-0.8 x 109/L).

Liver injury: Clinically significant cases of liver injury, including elevated serum aminotransferases (greater than 5 times the upper limit of normal) and elevated total bilirubin (greater than 2 times the upper limit of normal), have been reported with dimethyl fumarate. These cases resolved upon treatment discontinuation. Liver function should be checked before starting treatment and monitored during treatment as clinically indicated.

Flushing: Flushing (warmth, redness, itching, or burning sensation of the skin) is one of the most common side effects, occurring in approximately 34-40% of patients in clinical trials. Flushing is generally mild to moderate in severity and tends to decrease over time, with most patients reporting improvement after the first month of treatment. Taking the capsules with food and/or taking 325 mg of non-enteric-coated aspirin approximately 30 minutes prior to the dose may reduce flushing.

Gastrointestinal events: Gastrointestinal side effects including diarrhoea, nausea, abdominal pain, and vomiting are common, particularly during the first month of treatment. Taking the capsule with food (not on an empty stomach) can help reduce these effects. A temporary dose reduction to 120 mg twice daily may be considered for patients who do not tolerate the maintenance dose.

Important Warning: Progressive Multifocal Leukoencephalopathy (PML) PML is a rare but potentially fatal brain infection that can occur in patients with prolonged severe lymphopenia. Contact your doctor immediately if you experience new or worsening neurological symptoms such as progressive weakness on one side of the body, clumsiness, vision problems, confusion, memory changes, or personality changes that persist for several days.

Pregnancy and Breastfeeding

Dimethyl fumarate is not recommended during pregnancy unless the clinical condition of the woman requires treatment and the benefit justifies the potential risk to the foetus. Animal studies have shown reproductive toxicity at doses higher than those used in humans, but there are limited data from the use of dimethyl fumarate in pregnant women. Women of childbearing potential should use effective contraception during treatment and for at least 4 weeks after discontinuation.

If pregnancy occurs during treatment, discontinuation of dimethyl fumarate should be considered. The patient and physician should discuss the risks and benefits of continuing therapy during pregnancy. Pregnancy registries and post-marketing surveillance data are being collected to further evaluate the safety of dimethyl fumarate during pregnancy.

It is not known whether dimethyl fumarate or its metabolites are excreted in human breast milk. Because many drugs are excreted in human milk and because of the potential for adverse reactions in the nursing infant, a decision should be made whether to discontinue breastfeeding or to discontinue therapy, taking into account the importance of the therapy to the mother.

How Does Dimethyl Fumarate Pharmathen Interact with Other Drugs?

Quick Answer: Dimethyl fumarate has a relatively low drug interaction profile because it is not metabolised through the cytochrome P450 enzyme system. However, concurrent use with other immunosuppressants or nephrotoxic drugs should be avoided, and live vaccines should not be administered during treatment.

Dimethyl fumarate undergoes rapid presystemic hydrolysis by esterases to its active metabolite monomethyl fumarate (MMF), which is subsequently metabolised via the tricarboxylic acid (TCA) cycle. This metabolic pathway does not involve the cytochrome P450 (CYP450) enzyme system, which means dimethyl fumarate is unlikely to cause clinically significant pharmacokinetic interactions with drugs metabolised by CYP450 enzymes. In vitro studies have confirmed that dimethyl fumarate and MMF do not inhibit or induce major CYP450 isoenzymes (CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4).

However, several clinically important pharmacodynamic interactions should be considered when using dimethyl fumarate. The immunomodulatory effects of the drug mean that certain combinations require careful monitoring or avoidance altogether. Below is a summary of the key drug interactions.

Major Interactions

Major Drug Interactions
Interacting Drug/Class Interaction Effect Recommendation
Other immunosuppressants (e.g., azathioprine, methotrexate, ciclosporin) Additive immunosuppression; increased risk of infection including PML Avoid concurrent use; allow adequate washout period when switching therapies
Anti-neoplastic agents Enhanced immunosuppression; increased risk of serious infections Contraindicated in concurrent use
Live and live-attenuated vaccines Reduced vaccine efficacy; risk of infection from live vaccine organisms Avoid live vaccines during treatment; complete vaccinations at least 4-6 weeks before starting
Other fumaric acid derivatives (e.g., diroximel fumarate, Fumaderm) Same active metabolite (MMF); additive effects and toxicity Do not combine; these are alternative formulations, not complementary treatments

Minor Interactions

Minor Drug Interactions
Interacting Drug/Class Interaction Effect Recommendation
Nephrotoxic drugs (e.g., aminoglycosides, NSAIDs, contrast agents) Potential additive renal effects; dimethyl fumarate can cause proteinuria and renal tubular injury Monitor renal function more frequently if concurrent use is necessary
Inactivated vaccines Potentially reduced immune response to vaccine Can be administered; antibody response may be diminished in patients with lymphopenia
Aspirin (non-enteric-coated, 325 mg) No pharmacokinetic interaction; may help reduce flushing Can be taken 30 minutes before dimethyl fumarate to manage flushing
Oral contraceptives No significant interaction identified in clinical studies No dose adjustment needed; contraceptive efficacy is maintained

When switching from another disease-modifying therapy to dimethyl fumarate, an appropriate washout period should be observed to minimise the risk of additive immunosuppression. The duration of the washout period depends on the half-life and mechanism of action of the previous therapy. For example, after fingolimod, a washout period of at least 6 weeks is recommended to allow lymphocyte counts to recover. After natalizumab, a washout period of 2-3 months is typically advised. Your neurologist will determine the appropriate timing based on your individual situation.

What Is the Correct Dosage of Dimethyl Fumarate Pharmathen?

Quick Answer: The starting dose is 120 mg twice daily for 7 days, then the maintenance dose is 240 mg twice daily. Capsules should be swallowed whole with food. Do not crush, chew, or open the capsules, as the gastro-resistant coating protects the active substance from stomach acid.

Adults

The recommended starting dose is 120 mg (one capsule of the 120 mg strength) taken orally twice daily for the first 7 days of treatment. After this initial titration period, the dose is increased to the maintenance dose of 240 mg (one capsule of the 240 mg strength) taken orally twice daily. This titration schedule is designed to reduce the incidence and severity of flushing and gastrointestinal side effects that are most common during the early weeks of treatment.

Standard Adult Dosing Schedule

  • Days 1-7 (titration): 120 mg twice daily (morning and evening)
  • Day 8 onwards (maintenance): 240 mg twice daily (morning and evening)
  • Total daily dose: 480 mg (maintenance)

The capsules should be swallowed whole with water, taken with food (with or shortly after a meal). Swallowing the capsule whole is important because the gastro-resistant coating is designed to prevent the release of the active substance in the stomach, instead delivering it to the small intestine for absorption. Crushing, chewing, or opening the capsule destroys the enteric coating and can lead to increased gastrointestinal irritation and altered drug absorption.

A temporary dose reduction to 120 mg twice daily may be considered for patients who have difficulty tolerating the maintenance dose due to flushing or gastrointestinal side effects. The maintenance dose of 240 mg twice daily should be resumed within 4 weeks. If the patient continues to be unable to tolerate the maintenance dose, discontinuation of treatment should be considered.

Children and Adolescents

The safety and efficacy of dimethyl fumarate in children and adolescents below 18 years of age have not been established. No data are available from controlled clinical trials in the paediatric population. Therefore, Dimethyl Fumarate Pharmathen is not recommended for use in patients under 18 years of age. Research is ongoing to evaluate the use of dimethyl fumarate in paediatric MS, and preliminary observational data suggest a similar safety and tolerability profile to adults, but formal dosing recommendations cannot be made at this time.

Elderly Patients

Clinical studies with dimethyl fumarate included a limited number of patients aged 55 years and older, and did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. In general, dose selection for elderly patients should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. No specific dose adjustment is required based on age alone, but monitoring should be more frequent to detect potential adverse effects early, particularly lymphopenia and liver dysfunction.

Missed Dose

If you miss a dose of dimethyl fumarate, do not take a double dose to make up for the missed one. Simply take the next dose at the regularly scheduled time. If a dose is missed, the timing of subsequent doses should not be altered. It is helpful to establish a consistent daily routine for taking the medication, such as with breakfast and dinner, to minimise the risk of missing doses. Consistent adherence to the dosing schedule is important for maintaining optimal drug levels and therapeutic efficacy.

Overdose

There is limited experience with overdose of dimethyl fumarate. In the event of an overdose, no specific antidote is available. Supportive care and symptomatic treatment should be provided as appropriate. Because dimethyl fumarate is rapidly metabolised and its active metabolite (MMF) has a short half-life of approximately 1 hour, haemodialysis is not expected to be an effective method of removal. If you suspect an overdose, contact your doctor or poison control centre immediately, or go to the nearest hospital emergency department.

What Are the Side Effects of Dimethyl Fumarate Pharmathen?

Quick Answer: The most common side effects are flushing (34-40% of patients) and gastrointestinal symptoms including diarrhoea, nausea, and abdominal pain. These tend to improve after the first 2-3 months of treatment. Serious but rare side effects include progressive multifocal leukoencephalopathy (PML), severe lymphopenia, and liver injury.

Like all medicines, dimethyl fumarate can cause side effects, although not everybody gets them. The overall safety profile of dimethyl fumarate has been established through extensive clinical trial experience involving over 2,600 patients and confirmed through long-term extension studies with follow-up of up to 13 years. The most frequently reported side effects are flushing and gastrointestinal events, both of which tend to be most prominent during the initial period of treatment and decrease over time with continued use.

The side effects are categorised below according to their frequency of occurrence, based on data from clinical trials and post-marketing surveillance. Understanding the frequency and nature of side effects can help you and your healthcare provider make informed decisions about treatment and recognise adverse events early.

Very Common

Affects more than 1 in 10 people
  • Flushing (warmth, redness, itching, or burning sensation of the skin)
  • Diarrhoea
  • Nausea
  • Abdominal pain or abdominal cramping

Common

Affects 1 to 10 in 100 people
  • Vomiting
  • Dyspepsia (indigestion)
  • Gastritis (stomach inflammation)
  • Gastrointestinal disorder
  • Hot flush
  • Pruritus (itching)
  • Rash or erythema (skin redness)
  • Feeling of burning sensation
  • Proteinuria (protein in urine)
  • Lymphopenia (decreased lymphocyte count)
  • Leukopenia (decreased white blood cell count)
  • Elevated liver enzymes (ALT, AST)
  • Albumin in urine
  • Ketones in urine

Uncommon

Affects 1 to 10 in 1,000 people
  • Lymphocyte count decreased below 0.5 x 109/L (severe lymphopenia)
  • Hypersensitivity reactions
  • Anaphylaxis (severe allergic reaction)
  • Angioedema (swelling of face, lips, tongue, or throat)

Rare

Affects fewer than 1 in 1,000 people
  • Progressive multifocal leukoencephalopathy (PML)
  • Severe liver injury (hepatotoxicity)
  • Herpes zoster (shingles) reactivation
  • Serious opportunistic infections

Managing flushing: Flushing is the most distinctive side effect of dimethyl fumarate and is thought to be mediated by prostaglandin pathways. It typically presents as warmth, redness, itching, or a burning sensation of the skin, most commonly on the face, neck, and upper chest. Several strategies can help manage flushing: taking the capsule with food, taking 325 mg of non-enteric-coated aspirin 30 minutes before the dose, gradual dose titration at the start of treatment, and taking the capsule at bedtime (for the evening dose). In most patients, flushing diminishes significantly within the first month of treatment and becomes infrequent after 2-3 months.

Managing gastrointestinal symptoms: Gastrointestinal side effects are most common during the first month of treatment and typically improve with continued therapy. Taking the capsules with food, particularly with protein-rich meals, can help reduce these symptoms. Temporary dose reduction to 120 mg twice daily for up to 4 weeks may be helpful for patients with persistent gastrointestinal intolerance. Your doctor may also prescribe anti-emetic or anti-diarrhoeal medications for short-term symptom relief.

If you experience any side effects, including any not listed above, tell your healthcare provider. You can also report side effects directly to your national adverse drug reaction reporting system. By reporting side effects, you help provide more information on the safety of this medicine.

How Should You Store Dimethyl Fumarate Pharmathen?

Quick Answer: Store below 30°C in the original blister packaging to protect from light. Do not store capsules outside the blister for more than 7 days. Keep out of reach of children and do not use after the expiry date.

Proper storage of Dimethyl Fumarate Pharmathen is essential to maintain the stability and efficacy of the medicine. The gastro-resistant capsules are sensitive to moisture and light, which is why they are packaged in protective blister packs. Following the correct storage instructions ensures that the drug remains effective throughout its shelf life.

Store the capsules at temperatures below 30°C (86°F). Do not refrigerate or freeze. The capsules should be kept in the original blister packaging until ready to use, as this protects them from light and moisture. If capsules need to be temporarily stored outside the blister (for example, in a weekly pill organiser), they should not be stored outside the blister for more than 7 days at temperatures below 30°C.

Do not use Dimethyl Fumarate Pharmathen after the expiry date stated on the blister and the carton after “EXP”. The expiry date refers to the last day of that month. Keep this medicine out of the sight and reach of children. Store in a dry place away from direct sunlight and heat sources.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment. If you notice any visible signs of deterioration, such as discolouration or damage to the capsules, do not take them and consult your pharmacist.

What Does Dimethyl Fumarate Pharmathen Contain?

Quick Answer: Each capsule contains 120 mg or 240 mg of the active substance dimethyl fumarate. The capsule also contains inactive ingredients including microcrystalline cellulose, croscarmellose sodium, talc, silica, magnesium stearate, and enteric coating components.

Understanding the composition of your medicine is important, particularly if you have known allergies or intolerances to specific pharmaceutical excipients. Dimethyl Fumarate Pharmathen is available in two strengths, each with a distinct capsule appearance to help prevent dosing errors.

Active substance: Each gastro-resistant hard capsule contains either 120 mg or 240 mg of dimethyl fumarate (also known as dimethyl (E)-butenedioate, CAS number 624-49-7, molecular formula C6H8O4, molecular weight 144.13 g/mol). Dimethyl fumarate is a methyl ester of fumaric acid, a naturally occurring substance found in the body as an intermediate in the citric acid cycle.

Inactive ingredients (excipients): The other ingredients are microcrystalline cellulose, croscarmellose sodium, talc, colloidal anhydrous silica, and magnesium stearate. The capsule shell contains hypromellose, methacrylic acid-ethyl acrylate copolymer (1:1), talc, triethyl citrate, titanium dioxide (E171), simethicone, and the colourant brilliant blue FCF (E133) for the 240 mg capsule or iron oxide yellow (E172) for the 120 mg capsule.

The 120 mg gastro-resistant capsule has a green cap and white body, with “120 mg” printed on the body. The 240 mg gastro-resistant capsule has a green cap and green body, with “240 mg” printed on the body. The gastro-resistant coating is a critical component that ensures the active substance is released in the small intestine rather than the stomach, improving both absorption and tolerability.

If you are allergic to any of the listed excipients, discuss this with your doctor or pharmacist before starting treatment. In particular, patients with known hypersensitivity to methacrylic acid copolymers or any of the colourants should inform their healthcare provider.

Frequently Asked Questions About Dimethyl Fumarate Pharmathen

Dimethyl Fumarate Pharmathen is a generic medicine that contains the same active substance (dimethyl fumarate) as Tecfidera, which is the original branded product manufactured by Biogen. Both medicines contain the same dose of the active substance and are available in the same strengths (120 mg and 240 mg). The EMA has confirmed that Dimethyl Fumarate Pharmathen is bioequivalent to Tecfidera, meaning it is absorbed into the body at the same rate and to the same extent. The inactive ingredients (excipients) may differ slightly between the two products, but this does not affect the clinical efficacy or safety. Generics undergo the same rigorous quality standards as the reference medicine.

Dimethyl fumarate begins to exert its immunomodulatory effects within weeks of starting treatment, but the full clinical benefit may not be apparent for several months. In clinical trials, significant reductions in MRI lesion activity were observed within the first 6 months. The effect on reducing relapses was measured over 2 years, with the annualised relapse rate decreasing by 44-53% compared to placebo. It is important to continue treatment as prescribed, even if you feel well, because disease-modifying therapies work by preventing future relapses and disability progression rather than treating acute symptoms.

There are no specific warnings about alcohol consumption with dimethyl fumarate. However, alcohol can potentially worsen flushing symptoms and gastrointestinal side effects. It is generally advisable to moderate alcohol intake, particularly during the first few months of treatment when flushing and gastrointestinal symptoms are most common. Alcohol can also contribute to liver burden, and since dimethyl fumarate may affect liver function, moderation is prudent. Discuss your alcohol consumption habits with your doctor for personalised advice.

Flushing is a common side effect that typically improves over time. To manage flushing: (1) always take the capsule with food, preferably a protein-rich meal; (2) take 325 mg of non-enteric-coated aspirin about 30 minutes before the dose; (3) take the evening dose at bedtime to sleep through the flushing; (4) avoid hot beverages, spicy foods, and alcohol around the time of dosing. If flushing remains severe despite these measures, your doctor may temporarily reduce the dose to 120 mg twice daily for up to 4 weeks. In most patients, flushing improves significantly within the first month and is rarely a reason for permanent discontinuation.

Blood tests are an essential part of monitoring during dimethyl fumarate treatment. A complete blood count (CBC) with differential including lymphocyte count should be obtained before starting treatment, then every 3 months during the first year, and at least every 6-12 months thereafter. Liver function tests should be performed before starting and periodically during treatment. If lymphocyte counts fall below 0.5 x 109/L, more frequent monitoring (every 1-2 months) is required, and treatment discontinuation should be considered if severe lymphopenia persists for more than 6 months. Your neurologist will advise on the exact monitoring schedule based on your individual risk factors.

Dimethyl fumarate should not be taken together with other disease-modifying therapies for MS, as this can lead to additive immunosuppression and significantly increased risk of infections, including PML. This includes other oral DMTs such as fingolimod and teriflunomide, injectable therapies such as interferons and glatiramer acetate, and infusion therapies such as natalizumab and ocrelizumab. When switching between MS therapies, an appropriate washout period is required to allow the previous drug's immunological effects to resolve before starting dimethyl fumarate. However, short-term corticosteroids for treating acute MS relapses can be used during dimethyl fumarate treatment.

All information is based on international medical guidelines and peer-reviewed research: European Medicines Agency (EMA) Summary of Product Characteristics for dimethyl fumarate, FDA prescribing information, the DEFINE and CONFIRM Phase III clinical trials published in the New England Journal of Medicine, American Academy of Neurology (AAN) practice guidelines for disease-modifying therapies in MS, ECTRIMS/EAN guidelines on pharmacological treatment of MS, and post-marketing safety data. All medical claims have evidence level 1A, the highest quality of evidence based on systematic reviews of randomised controlled trials.

References

  1. European Medicines Agency (EMA). Dimethyl fumarate Pharmathen – Summary of Product Characteristics. EMA/CHMP, 2023. Available at: www.ema.europa.eu
  2. Gold R, Kappos L, Arnold DL, et al. Placebo-Controlled Phase 3 Study of Oral BG-12 for Relapsing Multiple Sclerosis (DEFINE study). N Engl J Med. 2012;367(12):1098-1107. doi:10.1056/NEJMoa1114287
  3. Fox RJ, Miller DH, Phillips JT, et al. Placebo-Controlled Phase 3 Study of Oral BG-12 or Glatiramer in Multiple Sclerosis (CONFIRM study). N Engl J Med. 2012;367(12):1087-1097. doi:10.1056/NEJMoa1206328
  4. Gold R, Arnold DL, Bar-Or A, et al. Long-term effects of delayed-release dimethyl fumarate in multiple sclerosis: Interim analysis of ENDORSE, a randomized extension study. Mult Scler. 2017;23(2):253-265. doi:10.1177/1352458516649037
  5. Montalban X, Gold R, Thompson AJ, et al. ECTRIMS/EAN Guideline on the pharmacological treatment of people with multiple sclerosis. Mult Scler. 2018;24(2):96-120. doi:10.1177/1352458517751049
  6. 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. doi:10.1212/WNL.0000000000005347
  7. Linker RA, Lee DH, Ryan S, et al. Fumaric acid esters exert neuroprotective effects in neuroinflammation via activation of the Nrf2 antioxidant pathway. Brain. 2011;134(Pt 3):678-692. doi:10.1093/brain/awq386
  8. World Health Organization (WHO). Model List of Essential Medicines, 23rd edition. WHO, 2023.
  9. British National Formulary (BNF). Dimethyl fumarate. National Institute for Health and Care Excellence (NICE), 2024.
  10. US Food and Drug Administration (FDA). Tecfidera (dimethyl fumarate) Prescribing Information. Revised 2023.

Editorial Team

This article has been written and medically reviewed by the iMedic Medical Editorial Team, comprising board-certified physicians specialising in clinical pharmacology, neurology, and internal medicine. Our team follows the GRADE evidence framework and adheres to international medical guidelines from the WHO, EMA, FDA, and leading neurological societies.

Medical Writing

iMedic Medical Content Team – Specialists in neuropharmacology and clinical medicine with expertise in multiple sclerosis therapeutics.

Medical Review

iMedic Medical Review Board – Independent panel of neurologists and clinical pharmacologists who verify accuracy against current evidence and international guidelines.

All content is independently produced with no pharmaceutical company sponsorship or commercial funding. We declare no conflicts of interest. For questions about our editorial process, visit our Editorial Standards page or contact us.