Drug Guide
Dimethyl Fumarate
Classification
Therapeutic: Multiple Sclerosis (MS) Disease-Modifying Therapy
Pharmacological: Immunomodulator, Anti-inflammatory
FDA Approved Indications
- Relapsing forms of multiple sclerosis to reduce frequency of exacerbations and delay disability progression
Mechanism of Action
Dimethyl fumarate activates the Nrf2 pathway, leading to an anti-inflammatory and cytoprotective response that reduces inflammatory cell infiltration into the central nervous system and protects neurons from oxidative stress.
Dosage and Administration
Adult: 240 mg twice daily or 120 mg twice daily for 7 days, then increased to 240 mg twice daily
Pediatric: Not approved for pediatric use
Geriatric: Use with caution; no specific dose adjustment recommended but monitor closely due to potential increased risk of adverse effects
Renal Impairment: No dose adjustment necessary
Hepatic Impairment: No dose adjustment required
Pharmacokinetics
Absorption: Well absorbed orally, undergoes first-pass metabolism
Distribution: widely distributed in tissues with high affinity for erythrocytes
Metabolism: Hydrolyzed by esterases to active metabolite monomethyl fumarate and other metabolites
Excretion: Excreted primarily in the urine of metabolites
Half Life: Approximately 12 hours for monomethyl fumarate
Contraindications
- Allergy to dimethyl fumarate or to any component of the formulation
Precautions
- History of hypersensitivity to fumarates, history of progressive multifocal leukoencephalopathy (PML), active severe infections, lymphopenia (<0.5 x 10^9/L)
Adverse Reactions - Common
- Flushing (Likely)
- Diarrhea (Common)
- Nausea (Common)
- Upper respiratory tract infection (Common)
- Elevated liver enzymes (Uncommon)
Adverse Reactions - Serious
- Progressive multifocal leukoencephalopathy (PML) (Rare)
- Severe infections (e.g., herpes zoster, pneumonia) (Rare)
- Severe lymphopenia leading to infection risk (Rare)
Drug-Drug Interactions
- No significant interactions reported with common MS therapies
Drug-Food Interactions
- No specific food interactions
Drug-Herb Interactions
- Limited data, caution advised with herbal products that affect immune function
Nursing Implications
Assessment: Monitor lymphocyte counts at baseline and regularly during therapy; assess liver enzymes periodically; evaluate for signs of infection
Diagnoses:
- Risk for infection related to lymphopenia
- Imbalanced nutrition: less than body requirements due to gastrointestinal side effects
Implementation: Administer with food if gastrointestinal upset occurs; educate patient on infection risk and signs to watch for
Evaluation: Effective reduction in relapse rate; absence of adverse effects such as severe lymphopenia or PML
Patient/Family Teaching
- Take medication with food to reduce flushing and gastrointestinal symptoms
- Report signs of infection such as fever, sore throat, or flu-like symptoms immediately
- Maintain regular blood tests as scheduled
- Avoid live vaccines during therapy
Special Considerations
Black Box Warnings:
- Progressive multifocal leukoencephalopathy (PML) with fatal and debilitating outcomes
Genetic Factors: None specific to this drug
Lab Test Interference: May cause lymphopenia, liver enzyme elevations, which require monitoring
Overdose Management
Signs/Symptoms: Intensified gastrointestinal or flushing symptoms, lymphopenia, or infection
Treatment: Supportive care, monitor blood counts; no specific antidote
Storage and Handling
Storage: Store at room temperature, 15-30°C (59-86°F), away from moisture and heat
Stability: Stable until the expiration date on the package