Mean Percentage of Levothyroxine Dosage Increase in Patients With Hypothyroidism Started on Enteral Feeding

The Effect of Holding Tube Feeding When Administering Levothyroxine on the Mean Percentage of Levothyroxine Dosage Increase in Patients With Hypothyroidism Started on Enteral Feeding

The study aims to describe the changes in Levothyroxine dosage requirements in patients with hypothyroidism started on enteral feeding, and assess whether giving levothyroxine on empty stomach affects the mean percentage increase expected in Levothyroxine dosage in these patients.

The study will be a Randomized Controlled trial comparing the mean percentage of Levothyroxine dosage change in hypothyroid patients after the starting of enteral feeding in an inpatient setting in two different groups: a control group where Levothyroxine will be administered with continuous enteral nutrition, and an intervention group where enteral nutrition will be held for two hours before and two hours after the Levothyroxine administration.

The enrollment of eligible patients will be over two to three years and follow up will continue for the duration of the hospital stay or 12 weeks, which ever occurs earlier. Eligible patients will have thyroid function tests at enrollment (within three days of the starting of the tube feeding) and afterwards weekly. Levothyroxine dosage will be adjusted by the endocrinology research team according to the thyroid function results. Initial Levothyroxine dosage and subsequent dosages will be recorded and the mean percentage decrease or increase of Levothyroxine dosage required will be measured in each group. An eventual difference between the two groups mean percentage change will be tested for statistical significance.

Inclusion Criteria:

• Adults admitted to Maimonides Medical Center
• Started on Enteral feeding within 3 days of enrollment: tube feeding, Percutaneous Endoscopic Gastrostomy or PEG tube feeding, or Jejunostomy tube feeding.
• History of Hypothyroidism on a stable dose of Levothyroxine for at least four weeks prior to enteral feeding
• TSH 0.2-10 mIU/ml at enrollment

Exclusion Criteria:

• Concomitant administration of medications that affect thyroid function test including Cholestyramine, Sucralfate, Amiodarone, Lithium, Dopamine, Dobutamine and Dilantin at enrollment.
• Pregnancy
• Known untreated disease or surgery of the small intestine specifically the Jejenum.