Drug interactions
Magnesium hydroxide + Sodium phosphates
Severity: Moderate
Magnesium hydroxide and Sodium phosphates: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Magnesium laxatives and sodium phosphate preparations are both osmotic agents. Combining them adds fluid and electrolyte shifts, and magnesium also binds phosphate. This may cause electrolyte disturbance and reduce the intended phosphate effect.
What this interaction means in plain words
Magnesium hydroxide and Sodium phosphates can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Magnesium binds phosphate in the gut and the two osmotic agents have additive effects on fluid and electrolyte balance.
What to do
Avoid concurrent use where possible and choose one agent. If both are needed, monitor serum phosphate, magnesium and hydration.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Magnesium hydroxide
Frequently asked questions
Can I take Magnesium hydroxide with Sodium phosphates?
MediHelp rates the interaction as moderate. Magnesium hydroxide and Sodium phosphates can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Magnesium laxatives and sodium phosphate preparations are both osmotic agents. Combining them adds fluid and electrolyte shifts, and magnesium also binds phosphate. This may cause electrolyte disturbance and reduce the intended phosphate effect.
How serious is the interaction between Magnesium hydroxide and Sodium phosphates?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use where possible and choose one agent. If both are needed, monitor serum phosphate, magnesium and hydration.
What other medicines interact with Magnesium hydroxide?
MediHelp also lists interactions of Magnesium hydroxide with, for example, Ciprofloxacin, Dolutegravir, Gemifloxacin. The full list is on the Magnesium hydroxide page.
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