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

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.