Milk of Magnesia with Your Medication Regimen
Milk of magnesia (magnesium hydroxide) can be taken with most of your medications, but you must separate it from gabapentin by at least 2 hours to avoid reduced gabapentin absorption. 1
Critical Interaction: Gabapentin
The most important interaction is between milk of magnesia and gabapentin. Antacids containing magnesium and aluminum hydroxides reduce gabapentin bioavailability by approximately 20%. 1 However, this interaction is manageable:
- Take gabapentin at least 2 hours before milk of magnesia to reduce the interaction to approximately 10% reduction in absorption 1
- This timing strategy is explicitly supported by FDA labeling data 1
CNS Depressant Considerations
Your medication regimen includes multiple central nervous system (CNS) depressants: trazodone, lorazepam (Ativan), quetiapine, tizanidine (Zanaflex), and gabapentin. The 2019 AGS Beers Criteria warns that concurrent use of three or more CNS agents increases fall risk in older adults. 2 While milk of magnesia itself is not a CNS depressant, be aware of this cumulative sedation risk from your existing medications.
No Significant Interactions with Other Medications
Milk of magnesia does not have clinically significant interactions with your other medications:
- Trazodone: No documented interaction with magnesium-containing antacids 3
- Lorazepam (Ativan): Benzodiazepines do not have significant interactions with magnesium supplements 4
- Quetiapine: No direct pharmacokinetic interaction reported
- Tizanidine (Zanaflex): No documented interaction with magnesium hydroxide
- Nebivolol (Bystolic): Beta-blockers do not interact with magnesium-containing antacids 5
- Cetirizine (Zyrtec): Antihistamines have no significant interaction with magnesium hydroxide
Practical Dosing Strategy
To optimize your medication regimen with milk of magnesia:
- Take gabapentin first (or at your scheduled time)
- Wait at least 2 hours 1
- Then take milk of magnesia
- Your other medications can be taken at their regular times without specific timing adjustments relative to milk of magnesia
Safety Monitoring
While magnesium hydroxide is generally safe, monitor for excessive magnesium accumulation if you have:
- Bowel obstruction or severe constipation (can increase magnesium absorption) 6
- Kidney dysfunction (though your medications suggest normal renal function is likely)
- Symptoms of hypermagnesemia: confusion, muscle weakness, or cardiac rhythm changes 6
The risk of hypermagnesemia from milk of magnesia is low with normal kidney function and typical dosing, but has been reported in cases of bowel obstruction or excessive use. 6