361
Views
33
CrossRef citations to date
0
Altmetric
Original Research

Oral liquid levothyroxine solves the problem of tablet levothyroxine malabsorption due to concomitant intake of multiple drugs

, &
Pages 467-472 | Received 12 Nov 2016, Accepted 31 Jan 2017, Published online: 13 Feb 2017
 

ABSTRACT

Background: Unlike the tablet (TAB) formulation, liquid L-T4 (LIQ) is directly absorbed in the intestine. The aim of this study was to assess whether LIQ was superior to TAB, such that it would overcome the interference induced by co-ingestion of multiple interfering drugs (ID).

Methods: In this prospective cohort study, we recruited 11 patients with apparent reduced TAB absorption due to ≥ 2 ID, and switched them to LIQ while maintaining the daily dose and the co-ingestion of the ID. Serum TSH was assayed at least twice every eight weeks.

Results: Serum TSH was significantly lower on LIQ compared with TAB (P < 0.0001), in patients who took L-T4 for either replacement (P = 0.002) or TSH-suppression (P < 0.0001). This difference was evident already at the first measurement post-switch (P = 0.008 or P = 0.03). Regardless of the purpose of L-T4 therapy, patients who took two ID had lower serum TSH on LIQ compared with patients who took three ID (P = 0.0006). Interestingly, 2/3 patients who failed to reach target TSH levels while on LIQ took three ID.

Conclusions: LIQ overcomes the concurrent interference exerted by the ingestion of multiple ID. In such cases, switching from TAB to LIQ permits patients to reach target TSH within 8 weeks.

Acknowledgment

S Benvenga was an invited speaker at symposia organized by IBSA.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.