Can I take Magnesium and Solifenacin together?

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.

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.

Glaucoma

Do not take this medicine if you have narrow-angle glaucoma, as it can increase the pressure in your eye and worsen the condition.

Kidney disease

If you have severe kidney problems, you must use these medicines with caution; magnesium can build up to toxic levels, and solifenacin doses may need to be limited.

Urinary retention

Do not take solifenacin if you have difficulty emptying your bladder (urinary retention), as it may make this problem worse.

Alcohol

It is best to avoid or strictly limit alcohol while taking solifenacin. Both alcohol and solifenacin can cause drowsiness and blurred vision; combining them increases the risk of these side effects. Additionally, alcohol can irritate the bladder and worsen the symptoms solifenacin is intended to treat.

It is best to avoid or strictly limit alcohol when taking magnesium. Alcohol acts as a diuretic, which can increase the amount of magnesium your body loses through urine, potentially making the supplement less effective. Additionally, chronic alcohol use can lead to magnesium deficiency.

Grapefruit juice

You should avoid drinking large amounts of grapefruit juice while taking solifenacin. Grapefruit can increase the level of the medicine in your blood, which may increase the risk of side effects like dry mouth, constipation, and blurred vision.

Dairy products (Milk, Cheese, Yoghurt)

Avoid taking magnesium supplements at the same time as large amounts of dairy products. Dairy is high in calcium, and high doses of calcium can compete with magnesium for absorption in the gut, meaning you may not get the full benefit of your supplement. It is best to space them at least 2 hours apart.

Caffeine (Coffee, Tea, Energy drinks)

It is advisable to limit your caffeine intake. Caffeine is a bladder irritant and a diuretic, which can counteract the effects of solifenacin and worsen urinary urgency or frequency.

It is best to limit caffeine intake around the time you take magnesium. Like alcohol, caffeine has a mild diuretic effect and can increase the excretion of magnesium through the kidneys.

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.