Drug Interaction Between Vyvanse and Iron Supplements
There are no clinically significant pharmacokinetic or pharmacodynamic interactions between Vyvanse (lisdexamfetamine) and iron supplements. These medications can be taken together safely, though timing of administration may optimize iron absorption.
Key Clinical Considerations
No Direct Drug Interaction
- Iron supplements do not interact with amphetamine-class medications like Vyvanse through chelation or binding mechanisms 1
- The documented iron-drug interactions involve specific drug classes (tetracyclines, penicillamine, methyldopa, levodopa, carbidopa, ciprofloxacin, thyroxine, captopril) that form stable complexes with iron—stimulants are not among these 1
Optimal Dosing Strategy for Iron Absorption
While there is no interaction requiring separation, consider these evidence-based practices for iron supplementation:
- Take iron once daily rather than multiple times per day to minimize gastrointestinal side effects while maintaining efficacy 2
- Alternate-day dosing (every other day) may increase fractional iron absorption and reduce GI symptoms 2
- Limit elemental iron to 50-100 mg once daily, especially in patients with GI sensitivity 2
- Take iron on an empty stomach (1-2 hours before or after meals) for optimal absorption, though taking with small amounts of food may improve tolerability 2
Timing Recommendations
- Avoid tea or coffee within one hour of iron administration, as these inhibit absorption 2
- Vyvanse can be taken at any time relative to iron without concern for interaction
- Consider taking iron with vitamin C (250-500 mg) to enhance absorption, especially if taking with meals 2
When Oral Iron Fails
If gastrointestinal side effects become intolerable despite dosing adjustments:
- Try different oral iron formulations (ferrous gluconate or ferrous fumarate instead of ferrous sulfate) 2
- Consider ferric maltol, which demonstrates GI side effects comparable to placebo 2
- Switch to intravenous iron if oral iron causes intolerable symptoms—this is safe and effective in iron-deficient patients with normal renal function 3, 4
Common Pitfall to Avoid
Do not unnecessarily separate Vyvanse and iron supplements based on unfounded interaction concerns. The primary focus should be on optimizing iron absorption through proper timing relative to food and beverages, not relative to Vyvanse.