Can Tecfidera and Vyvanse Be Taken Together?
Yes, Tecfidera (dimethyl fumarate) can be taken concurrently with Vyvanse (lisdexamfetamine) as there are no known pharmacokinetic or pharmacodynamic interactions between these medications.
Pharmacological Basis for Safety
The FDA drug label for Tecfidera explicitly addresses drug interaction potential and provides reassuring data 1:
- No CYP450 involvement: Dimethyl fumarate is extensively metabolized by esterases (not cytochrome P450 enzymes) before reaching systemic circulation, with further metabolism occurring through the tricarboxylic acid (TCA) cycle
- No drug interaction studies identified: In vitro studies found no potential drug interactions with dimethyl fumarate or its active metabolite (monomethyl fumarate) in CYP inhibition/induction studies or P-glycoprotein studies
- No transporter interactions with stimulants: The drug interaction profile does not list amphetamines or related stimulants as problematic combinations
Vyvanse (lisdexamfetamine) is a prodrug converted to dextroamphetamine 2. Since Tecfidera's metabolism does not involve CYP450 enzymes and lisdexamfetamine's conversion occurs through hydrolysis, there is no shared metabolic pathway that would create interaction concerns.
Clinical Monitoring Recommendations
While the combination is safe from a pharmacokinetic standpoint, monitor for:
Tecfidera-Specific Monitoring
- Lymphocyte counts: Obtain baseline and monitor regularly, as Tecfidera can cause lymphopenia 1
- Liver function tests: Check serum aminotransferases, alkaline phosphatase, and total bilirubin before treatment and as clinically indicated 1
- Gastrointestinal symptoms: Watch for serious GI reactions (perforation, ulceration, hemorrhage), particularly in the first 6 months 1
- Flushing: Common (40% of patients) but typically mild-moderate and improves over time 1
Vyvanse-Specific Monitoring
- Cardiovascular parameters: Monitor heart rate and blood pressure regularly 3, 2
- Psychiatric symptoms: Watch for anxiety, insomnia, or mood changes 3
- Appetite and weight: Common stimulant side effects 4
Important Caveats
No aspirin needed for this combination: While aspirin (up to 325 mg) can be given 30 minutes before Tecfidera to reduce flushing 1, this is optional and not required for safety when combining with Vyvanse. The Tecfidera label confirms aspirin does not alter the pharmacokinetics of monomethyl fumarate 1.
Separate clinical indications: These medications treat different conditions (multiple sclerosis vs ADHD) and their concurrent use simply reflects management of comorbid conditions rather than any synergistic therapeutic strategy.
No dose adjustments required: Neither medication requires dose modification when used together, as there are no pharmacokinetic interactions 1.