Jaxteran (Dimethyl Fumarate)

• Jaxteran is used as a disease‑modifying therapy targeting the immune system in multiple sclerosis.
• Relapsing‑remitting multiple sclerosis: reduces annual relapse rate and delays disability progression.
• Active secondary progressive multiple sclerosis: decreases relapse frequency and slows worsening of neurological function.
• Clinically isolated syndrome at high risk of conversion: may delay onset of clinically definite multiple sclerosis.

• Dimethyl fumarate activates the nuclear factor erythroid 2‑related factor 2 (Nrf2) pathway, leading to increased expression of antioxidant and cytoprotective genes. This results in reduced oxidative stress and modulation of inflammatory cytokine production, which together dampen autoreactive immune responses implicated in multiple sclerosis pathology. The drug also influences lymphocyte trafficking and reduces the number of circulating pro‑inflammatory T cells, contributing further to its therapeutic effect.

Dimethyl fumarate is associated with a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Flushing: transient warmth and redness, often on the face or upper body.
• Gastrointestinal discomfort: nausea, abdominal pain, or diarrhea.
• Lymphopenia: reduction in peripheral blood lymphocyte count.
• Headache: mild to moderate intensity.

Serious or Rare Side Effects

• Progressive multifocal leukoencephalopathy (PML): rare opportunistic brain infection.
• Severe allergic reactions: including rash, angioedema, or anaphylaxis.
• Hepatic injury: elevated liver enzymes or hepatitis.

When prescribing dimethyl fumarate, clinicians should observe several precautionary measures to ensure patient safety.

• Monitor lymphocyte counts: perform baseline and periodic blood tests to detect lymphopenia.
• Assess liver function: check hepatic enzymes before initiation and during therapy.
• Evaluate infection risk: avoid use in patients with active infections or those receiving live vaccines.
• Counsel on flushing: advise patients that flushing may be mitigated by taking the medication with food.
• Review renal function: adjust use in severe renal impairment if necessary.
• Store at ambient temperature: keep below 25°C in the original packaging, protected from moisture.

Dimethyl fumarate may interact with other medicines, requiring attention to avoid reduced efficacy or increased toxicity.

Major Interactions (Avoid)

• Live attenuated vaccines: concurrent use can increase risk of vaccine‑derived infection.
• Other immunosuppressants: combined therapy may heighten infection risk and profound lymphopenia.
• Strong CYP inducers: may lower dimethyl fumarate exposure, reducing therapeutic effect.

Moderate Interactions (Monitor Closely)

• NSAIDs: may exacerbate gastrointestinal side effects.
• Antihypertensive agents: potential additive blood pressure lowering effect.