Can a magnesium oxide tablet be crushed and given through a Ryles (nasogastric) tube?

Magnesium Oxide Tablet Administration via Nasogastric Tube

Yes, magnesium oxide tablets can be crushed and administered through a Ryles (nasogastric) tube, but this should be done with specific precautions to ensure proper dissolution and avoid tube occlusion.

Key Administration Requirements

The appropriateness of administering any medication through an enteral tube must be confirmed before crushing, considering the site of drug delivery and potential interactions with enteral formula and feeding tubes 1. While magnesium oxide can be crushed for NG tube administration, this practice carries risks that must be carefully managed 2, 3.

Critical Timing Considerations

• Immerse crushed magnesium oxide tablets in water for no more than 1 minute before administration 4
• Prolonged immersion (10-30 minutes) in thickening agents or water can cause disintegration delay or complete non-disintegration in gastric acid 4
• Moisture-absorbed magnesium oxide tablets show significantly delayed disintegration, even with brief immersion 4

Proper Administration Technique

• Flush the tube with at least 30 mL of water before, between, and after each medication to prevent tube occlusion 1, 2
• Use appropriate ENFit-standard syringes and connectors to avoid misconnection errors 1, 2
• Administer medications individually through the tube, never mixing multiple drugs together 1
• Deliver the crushed tablet suspension immediately after preparation 4

Important Pharmacokinetic Considerations

• Approximately 90% of magnesium oxide dissolves within 120 minutes under appropriate conditions, forming an absorbable state 5
• About 15% of orally administered magnesium oxide is absorbed systemically, with peak plasma concentration occurring 3 hours after administration 5
• The remaining 85% is excreted via feces without absorption 5

Safety Warnings and Precautions

Crushing tablets exposes healthcare workers to drug particles and may alter drug absorption, potentially causing overdose or underdosing 3. For magnesium oxide specifically:

• Monitor for hypermagnesemia risk, particularly in patients with renal impairment 5
• Be aware that high doses can cause osmotic laxative effects through water retention in the intestinal lumen 6
• Magnesium oxide is soluble in dilute acid (gastric environment) but insoluble in water and alcohol 1

Clinical Pitfalls to Avoid

• Do not shake low-dose ENFit syringes to remove drug moat, as this exposes people to the drug and affects the dose delivered 1, 2
• Avoid prolonged contact between crushed tablets and water or thickening agents before administration 4
• Do not use moisture-absorbed or improperly stored magnesium oxide tablets 4
• Consult with a pharmacist before crushing any medication for NG tube administration 1, 2

Alternative Considerations

• Liquid formulations are preferred over crushed tablets when available 2
• For patients requiring long-term magnesium supplementation via NG tube, consider whether intravenous or subcutaneous magnesium administration might be more appropriate 1