Drug General Information (ID: DDI6XD0POW)
  Drug Name Thyroid, porcine Drug Info Simethicone Drug Info
  Drug Type Hormones Small molecule
  Therapeutic Class Thyroid Drugs Gi Agents

 Mechanism of Thyroid, porcine-Simethicone Interaction (Severity Level: Moderate)
     Complex formation Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Thyroid, porcine Simethicone
      Mechanism Binds to polyvalent cations Polyvalent cations
      Key Mechanism Factor 1
Factor Name Chelation
Factor Description Chelation is a direct drug interaction that usually involves the formation of dimers or trimers, resulting in larger complexes and poorer absorption.
      Mechanism Description
  • Decreased absorption of Simethicone due to formation of complexes caused by Thyroid, porcine 

Recommended Action
      Management It is recommended to separate the times of administration of levothyroxine and simethicone and antacids or other antacid-containing preparations (e.g., didanosine buffered tablets or pediatric oral solution) by at least 4 hours. Monitoring of serum TSH levels is recommended. Patients with gastrointestinal or malabsorption disorders may be at a greater risk of developing clinical or subclinical hypothyroidism due to this interaction.

References
1 Neafsey PJ "Levothyroxine and calcium interaction: timing is everything." Home Healthc Nurse 22 (2004): 338-9. [PMID: 15131426]
2 Product Information. Synthroid (levothyroxine). Abbott Pharmaceutical, Abbott Park, IL.
3 Schneyer CR "Calcium carbonate and reduction of levothyroxine efficacy." JAMA 279 (1998): 750. [PMID: 9508149]