Skip to main content

Can I take Magnesium and Solifenacin together?

Drug interaction guide

Taking magnesium (especially as an antacid) at the same time as solifenacin may slow down how quickly your body absorbs the solifenacin. This could potentially delay how well the medicine works for your bladder symptoms. Additionally, both substances can affect how your bowels work; solifenacin often causes constipation, while some forms of magnesium can cause diarrhoea or, conversely, certain antacids can worsen constipation.

Continue reading below

Why this happens

Magnesium-containing antacids can increase the pH level in the stomach and physically bind to other drugs, which slows down the rate at which solifenacin enters the bloodstream. There is also a minor 'pharmacodynamic' overlap where both drugs affect the digestive system in opposite or unpredictable ways.

What you should do

You can usually take both, but it is best to space them out. Try to take your solifenacin at least 2 hours before or 4 to 6 hours after taking a magnesium supplement or antacid. If you notice your bladder symptoms are not being controlled as well as usual, or if you suffer from severe constipation, speak with your pharmacist or doctor.

Continue reading below

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

Continue reading below

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 25 Jan 2026 | Originally published
flu eligibility checker

Ask, share, connect.

Browse discussions, ask questions, and share experiences across hundreds of health topics.

symptom checker

Feeling unwell?

Assess your symptoms online for free

Sign up to the Patient newsletter

Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.