Levothyroxine pseudo-malabsorption: testing and treatment in the outpatient setting
Open accessAbstract
Persistent elevation of thyroid stimulating hormone (TSH) is a common clinical problem in outpatient clinics treating patients with primary hypothyroidism. One challenge to practitioners involves predicaments where patients have an inadequate response to a seemingly appropriate dose of levothyroxine (L-T4). A patient's self-assessed compliance to hormone replacement therapy or verification refill history at the patient's pharmacy might not be a reliable form of confirmation of non-adherence to the drug by the patient, which has been referred to as "L-T4 pseudo-malabsorption." A fast and inexpensive tool to rule out true LT4 malabsorption and thereby properly diagnosing and ultimately successfully treat LT4 pseudo-malabsorption is available in the outpatient setting. This allows clinicians to identify which patients for individual support in adhering to their prescribed therapy and may also reduce unnecessary referrals for sub-specialty care by endocrinologists.
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IM or IV injection of LT4 once or twice weekly may also eliminate hypothyroidism due to pseudomalabsorption.
“In addition, IM or IV injection of LT4 once or twice weekly may also eliminate hypothyroidism due to pseudomalabsorption (128, 135, 138).”
From Levothyroxine: conventional and novel drug delivery formulations. (2023) · cites this paper as [135]
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Cites
Harington, C. R., & Barger, G. (1927) · Biochemical Journal · doi:10.1042/bj0210169 · Cited by 319 · see citing works
Ferrous sulfate reduces thyroxine efficacy in patients with hypothyroidism
Campbell, N. R. C., Hasinoff, B. B., Stalts, H., Rao, B., & Wong, N. C. W. (1992) · Annals of Internal Medicine · doi:10.7326/0003-4819-117-12-1010 · Cited by 231 · see citing works
Conditions and drugs interfering with thyroxine absorption
Liwanpo, L., & Hershman, J. M. (2009) · Best Practice & Research Clinical Endocrinology & Metabolism · doi:10.1016/j.beem.2009.06.006 · Cited by 222 · see citing works
Effect of calcium carbonate on the absorption of levothyroxine
Singh, N. (2000) · JAMA · doi:10.1001/jama.283.21.2822 · Cited by 219 · see citing works
Gaitonde, D., Rowley, K. D., & Sweeney, L. (2012) · South African Family Practice · doi:10.1080/20786204.2012.10874256 · Cited by 209 · see citing works
Timing of levothyroxine administration affects serum thyrotropin concentration
Bach-Huynh, T.-G., Nayak, B., Loh, J., Soldin, S., & Jonklaas, J. (2009) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2009-0860 · Cited by 198 · see citing works
Altered intestinal absorption of L-thyroxine caused by coffee
Benvenga, S., Bartolone, L., Pappalardo, M. A., Russo, A., Lapa, D., Giorgianni, G., Saraceno, G., & Trimarchi, F. (2008) · Thyroid · doi:10.1089/thy.2007.0222 · Cited by 191 · see citing works
Delayed Intestinal Absorption of Levothyroxine
BENVENGA, S., BARTOLONE, L., SQUADRITO, S., GIUDICE, F. L., & TRIMARCHI, F. (1995) · Thyroid · doi:10.1089/thy.1995.5.249 · Cited by 156 · see citing works
The influence of cholestyramine on thyroxine absorption
Northcutt, R. C. (1969) · JAMA: The Journal of the American Medical Association · doi:10.1001/jama.1969.03160100047012 · Cited by 144 · see citing works
Liel, Y., Harman-Boehm, I., & Shany, S. (1996) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jcem.81.2.8636317 · Cited by 129 · see citing works
Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report
Centanni, M., Benvenga, S., & Sachmechi, I. (2017) · Journal of Endocrinological Investigation · doi:10.1007/s40618-017-0706-y · Cited by 113 · see citing works
Pseudomalabsorption of levothyroxine
Ain, K. B. (1991) · JAMA: The Journal of the American Medical Association · doi:10.1001/jama.1991.03470150090036 · Cited by 100 · see citing works
New medications which decrease levothyroxine absorption
John-Kalarickal, J., Pearlman, G., & Carlson, H. E. (2007) · Thyroid · doi:10.1089/thy.2007.0060 · Cited by 82 · see citing works
The Acute Effect of Calcium Carbonate on the Intestinal Absorption of Levothyroxine
Singh, N., Weisler, S. L., & Hershman, J. M. (2001) · Thyroid · doi:10.1089/105072501753211046 · Cited by 77 · see citing works
Diagnosis and treatment of levothyroxine pseudomalabsorption.
Lips, D. J., Reisen, M. V., Voigt, V., & Venekamp, W. J. R. R. (2004) · PubMed · Cited by 73 · see citing works
Gaitonde, D. Y., Rowley, K. D., & Sweeney, L. B. (2012) · PubMed · Cited by 73 · see citing works
Systematic appraisal of lactose intolerance as cause of increased need for oral thyroxine
Cellini, M., Santaguida, M. G., Gatto, I., Virili, C., Del Duca, S. C., Brusca, N., Capriello, S., Gargano, L., & Centanni, M. (2014) · The Journal of Clinical Endocrinology & Metabolism · doi:10.1210/jc.2014-1217 · Cited by 72 · see citing works
Malabsorption of Thyroid Hormones After Jejunoileal Bypass for Obesity
AZIZI, F., BELUR, R., & ALBANO, J. (1979) · Annals of Internal Medicine · doi:10.7326/0003-4819-90-6-941 · Cited by 61 · see citing works
Thyroxine treatment: absorption, malabsorption, and novel therapeutic approaches
Centanni, M. (2013) · Endocrine · doi:10.1007/s12020-012-9814-9 · Cited by 56 · see citing works
The effect of antiepileptic drugs on thyroid hormonal function: causes and implications
Hamed, S. A. (2015) · Expert Review of Clinical Pharmacology · doi:10.1586/17512433.2015.1091302 · Cited by 56 · see citing works
Helicobacter pyloriinfection and drugs malabsorption
Lahner, E. (2014) · World Journal of Gastroenterology · doi:10.3748/wjg.v20.i30.10331 · Cited by 53 · see citing works
Benvenga, S., Di Bari, F., & Vita, R. (2017) · Endocrine · doi:10.1007/s12020-017-1244-2 · Cited by 51 · see citing works
Effects of antiepileptic drug on thyroid hormones in patients with epilepsy: A meta-analysis
Zhang, Y., Shen, C., Lai, Q., Fang, G., Ming, W., Lu, R., & Ding, M. (2016) · Seizure · doi:10.1016/j.seizure.2016.01.010 · Cited by 48 · see citing works
Del Duca, S. C., Santaguida, M. G., Brusca, N., Gatto, I., Cellini, M., Gargano, L., Verga Falzacappa, C., Frattaroli, F. M., Virili, C., & Centanni, M. (2015) · European Journal of Endocrinology · doi:10.1530/eje-15-0314 · Cited by 31 · see citing works
Van Wilder, N., Bravenboer, B., Herremans, S., Vanderbruggen, N., & Velkeniers, B. (2017) · European Thyroid Journal · doi:10.1159/000452489 · Cited by 31 · see citing works
Rapid levothyroxine absorption testing: a case series of nonadherent patients
Balla, M., Jhingan, R. M., & Rubin, D. J. (2015) · International Journal of Endocrinology and Metabolism · doi:10.5812/ijem.31051 · Cited by 30 · see citing works
Twice-weekly dosing for thyroxine replacement in elderly patients with primary hypothyroidism
Taylor, J., Williams, B. O., Frater, J., Stott, D. J., & Connell, J. (1994) · Journal of International Medical Research · doi:10.1177/030006059402200504 · Cited by 30 · see citing works
Ingestion of large amounts of papaya fruit and impaired effectiveness of levothyroxine therapy
Deiana, L., Marini, S., & Mariotti, S. (2012) · Endocrine Practice · doi:10.4158/ep11233.co · Cited by 28 · see citing works
Thyroid Hormone Replacement in Patients Following Thyroidectomy for Thyroid Cancer
Hannoush, Z. C., & Weiss, R. E. (2016) · Rambam Maimonides Medical Journal · doi:10.5041/rmmj.10229 · Cited by 27 · see citing works
Srinivas, V., & Oyibo, S. O. (2010) · Endocrine Practice · doi:10.4158/ep10224.cr · Cited by 23 · see citing works
Pseudomalabsorption of thyroid hormones: case report and review of the literature
Livadariu, E., Valdes‐Socin, H., Burlacu, M. C., Vulpoi, C., Daly, A., & Beckers, A. M. (2007) · Annales d Endocrinologie · doi:10.1016/j.ando.2007.09.003 · Cited by 22 · see citing works
Pseudomalabsorption de L-thyroxine: une forme de pathomimie
Molines, L., Fromont, I., Morlet-Barla, N., Nogueira, J.-P., Valéro, R., & Vialettes, B. (2007) · La Presse Médicale · doi:10.1016/j.lpm.2006.09.024 · Cited by 10 · see citing works
Flagged first, then by citations
Research works printed but not linked: 2
- [26]26. Molines L, Fromont I, Morlet-Berla N, et al. L-thyroxine pesudomalabsorption: a factitious disease. Press Med 2007; 36: 1390–1394. [DOI] [PubMed] [Google Scholar]
- [29]29. Butt M, Gupta N, Tan H, et al. Clinical application of the levothyroxine absorption test in the diagnosis of pseudo-malabsorption. Am J Case Rep 2014; 2: 253–255. [Google Scholar]
Cited by
Sorted by citations
Levothyroxine: conventional and novel drug delivery formulations.
Liu, H., Li, W., Zhang, W., Sun, S., & Chen, C. (2023) · Endocrine Reviews · doi:10.1210/endrev/bnac030 · Cited by 63 · see citing works
The levothyroxine absorption test: a four-year experience (2015-2018) at the Mayo Clinic
Gonzales, K. M., Stan, M. N., Morris, J. C., Bernet, V., & Castro, M. R. (2019) · Thyroid · doi:10.1089/thy.2019.0256 · Cited by 46 · see citing works
Levothyroxine absorption test to differentiate pseudomalabsorption from true malabsorption
Ghosh, S., Pramanik, S., Biswas, K., Bhattacharjee, K., Sarkar, R., Chowdhury, S., & Mukhopadhyay, P. (2020) · European Thyroid Journal · doi:10.1159/000504218 · Cited by 39 · see citing works
Levothyroxine absorption test results in patients with TSH elevation resistant to treatment
Yildirim Simsir, I., Soyaltin, U. E., & Ozgen, A. G. (2019) · Endocrine · doi:10.1007/s12020-019-01889-x · Cited by 16 · see citing works
Managing symptoms in hypothyroid patients on adequate levothyroxine: a narrative review
Razvi, S., Mrabeti, S., & Luster, M. (2020) · Endocrine Connections · doi:10.1530/ec-20-0205 · Cited by 15 · see citing works
Santos Monteiro, S., Santos, T. S., Lopes, A. M., Oliveira, J. C., Freitas, C., & Couto Carvalho, A. (2022) · Endocrine Connections · doi:10.1530/ec-22-0355 · Cited by 9 · see citing works
Refractory hypothyroidism to levothyroxine treatment: five cases of pseudomalabsorption
Elbasan, O. (2020) · Acta Endocrinologica (Bucharest) · doi:10.4183/aeb.2020.339 · Cited by 7 · see citing works
Oueslati, I., Terzi, A., Yazidi, M., Kamoun, E., Feki, M., & Chihaoui, M. (2025) · Endocrine · doi:10.1007/s12020-025-04312-w · Cited by 3 · see citing works
New era of community pharmacists in patient problem solving and preventive care
Mohiuddin, A. K. (2019) · The Journal of Community Health Management · doi:10.18231/2394-2738.2018.0036 · Cited by 3 · see citing works
Hanmayyagari, B. (2020) · IAR Journal of Medicine and Surgery Research · doi:10.47310/iarjmsr.2020.v01i01.07 · Cited by 2 · see citing works
New era of Community Pharmacists in patient problem solving and preventive care
Mohiuddin, A. K. (2018) · International Journal of Research and Development in Pharmacy and Life Sciences · doi:10.21276/ijrdpl.2278-0238.2018.7(6).3119-3129 · Cited by 1 · see citing works
Ayhan, Y. E., Bektay, M. Y., Yavuz, D. G., & Sancar, M. (2025) · BMC Endocrine Disorders · doi:10.1186/s12902-025-01914-3 · Cited by 1 · see citing works
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Amro, M., Lahham, E. E., Sawafta, A. J., Saifi, M., Saifi, N., Atrash, F., & Billan, S. (2025) · Clinical Case Reports · doi:10.1002/ccr3.71438 · Cited by 1 · see citing works
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- Authors
- Rdzak, G. M., Whitman, L. M., & Inzucchi, S. E.
- Affiliations
- Yale New Haven Hospital (US)
- Yale University (US)
- ORCID
- Inzucchi, Silvio E.
- Venue
- Therapeutic Advances in Endocrinology and Metabolism
- Publisher
- SAGE Publications
- Published
- 2018-04-28
- Volume
- 9
- Issue
- 7
- Pages
- 217-222
- ISSN
- 2042-0188 (ISSN-L)
- 2042-0196
- PMC
- PMC6022974
- OpenAlex
- W2800582893
- Cited by
- 14
- References
- 32
- Citations by year
- 2025: 3 · 2022: 2 · 2020: 4 · 2019: 4 · 2018: 1
- FWCI
- 1.79
- Type
- journal article
- Language
- en
- Open access
- green
- europepmc.org
- Locations
- Therapeutic Advances in Endocrinology and Metabolism (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Topics
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Health Sciences › Medicine › Family Practice › Medication Adherence and Compliance
- Health Sciences › Medicine › Surgery › Thyroid and Parathyroid Surgery
- Keywords
- levothyroxine, primary hypothyroidism, thyroid-stimulating hormone, medication adherence, outpatient management, thyroid hormone replacement
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