Comparison between liquid and tablet levothyroxine formulations in patients treated through enteral feeding tube

The majority of clinicians suggest that enteral feedings should be held 1-2 h prior to and after L-T4 administration despite lack of data for continuous enteral nutrition.

The aim of this study was to: (1) compare the thyroid hormonal profile in patients submitted to L-T4 treatment in tablets or liquid formulation with an enteral feeding tube; (2) evaluate the nursing compliance with the two different formulations.

20 euthyroid patients submitted to total laryngectomy and thyroidectomy consecutively started L-T4 treatment in tablets (Group T) or in liquid formulation (Group L) with enteral feeding tube the day after surgery. Tablets were crushed before administration and enteral feeding was stopped for 30 min before and after L-T4 treatment, whereas liquid formulation was placed into the nasoenteric tube immediately. A questionnaire about the preparation and administration of thyroxine replacement therapy was given to the nurses.

No difference of TSH, fT4 and fT3 before and after L-T4 treatment was observed among patients of Group L. A slightly serum TSH increase was observed in Group T, but not reaching statistical significance (2.50 ± 1.18 vs 2.94 ± 1.22 mUI/L), whereas no difference in fT4 and fT3 levels was found. Preparation and administration of liquid L-T4 was considered excellent by 12/13 nurses, whereas tablet formulation was considered poor by 10/13.

Our data showed that liquid L-T4 formulation can be administered directly through feeding tube with no need for an empty stomach, with a significant improvement in therapy preparation and administration by nurses.