Is Magnesium Safe with Theophylline?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Separate magnesium supplement intake from theophylline by at least 2 hours. Take theophylline first, then magnesium. Discuss supplementation with your pharmacist before starting.
Why this interaction occurs
Magnesium-containing supplements can reduce the gastrointestinal absorption of theophylline by forming complexes that slow or reduce uptake, potentially leading to subtherapeutic theophylline levels and loss of bronchodilator control. Additionally, magnesium and theophylline both influence smooth muscle relaxation, and concurrent use may unpredictably affect airway tone.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 13,216 reports mentioning Theophylline. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Theophylline + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Magnesium interactions → · All Theophylline interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.