Levothyroxine Administration: Crushing and Suspension Method
Levothyroxine tablets can be chewed or crushed, but only when following a specific preparation protocol—the FDA-approved method involves crushing the tablet and immediately suspending it in water for administration, particularly for patients who cannot swallow intact tablets. 1
FDA-Approved Crushing Protocol
For patients unable to swallow intact tablets, the FDA label provides explicit instructions for crushing levothyroxine: 1
- Crush the tablet immediately before administration 1
- Suspend the freshly crushed tablet in a small amount (5 to 10 mL) of water 1
- Administer the suspension immediately by spoon or dropper 1
- Ensure the patient ingests the full amount of the suspension to receive the complete dose 1
- Never store the suspension—it must be prepared fresh each time 1
Critical Timing and Administration Requirements
The crushing method does not eliminate the fundamental absorption requirements for levothyroxine:
- Administer on an empty stomach, one-half to one hour before breakfast 1
- Take with a full glass of water to avoid choking or gagging 1
- Maintain at least 4 hours separation from drugs that interfere with levothyroxine absorption 1
Primary Indication for Crushing
This crushing protocol is specifically designed for pediatric patients who cannot swallow intact tablets, though the FDA label does not restrict its use to children only 1. The method ensures complete dose delivery while maintaining proper absorption conditions.
Important Caveats About Food Interactions
- Do not administer crushed levothyroxine in foods that decrease absorption, particularly soybean-based infant formula 1
- Evaluate the need for dosage adjustments when regularly administering within one hour of certain foods that may affect absorption 1
Alternative Formulations for Absorption Issues
When tablet crushing proves problematic or absorption remains inadequate:
- Liquid levothyroxine formulations can be taken with meals without losing therapeutic efficacy, offering superior convenience 2
- Soft gel capsule formulations release the active ingredient more consistently at varying pH levels than tablets and can also be taken with meals 3, 2
- These alternative formulations may solve malabsorption caused by gastroparesis, certain drugs, bariatric surgery, or coffee 3, 4
- Liquid and softgel formulations improve medication adherence and quality of life compared to tablets taken 30 minutes before breakfast 2
Common Pitfall to Avoid
Never simply chew the tablet dry without the water suspension protocol—this risks incomplete dose delivery and unpredictable absorption 1. The FDA-approved method ensures the entire dose is consumed and maintains optimal conditions for absorption.