PMID- 24246350
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20160718
LR  - 20220331
IS  - 1934-2403 (Electronic)
IS  - 1530-891X (Linking)
VI  - 20
IP  - 3
DP  - 2014 Mar
TI  - Tablet levothyroxine (L-T4) malabsorption induced by proton pump inhibitor; a 
      problem that was solved by switching to L-T4 in soft gel capsule.
PG  - e38-41
LID - 10.4158/EP13316.CR [doi]
AB  - OBJECTIVE: To report a patient in whom the impaired absorption of tablet 
      levothyroxine (L-T4) due to a proton pump inhibitor (PPI) use was corrected by 
      switching the patient to the soft gel capsule. METHODS: A woman with Hashimoto's 
      thyroiditis-associated hypothyroidism (serum thyroid-stimulating hormone [TSH] 
      6.8-9.6 mU/L) had been treated with tablet L-T4 (100 mug/day). Because she used to 
      take pantoprazole just before L-T4 in the morning, TSH failed to normalize 
      (4.4-6.5 mU/L). Thus, the daily dose had been progressively increased to 125 and 
      150 mug/day, with serum TSH levels of 2.4 and 0.6 mU/L, respectively. RESULTS: 
      While maintaining pantoprazole, we switched the tablet L-T4 (150 g/day) to a soft 
      gel capsule (125 mug/day; Tirosint(R) capsule, IBSA, Lugano, Switzerland) and after 
      2 months, to 100 mug/day. Serum TSH was lower than under the equivalent regimens 
      with the tablet: 0.5 versus 2.4 mU/L (125 mug/day) and 2.4 versus 4.4 to 6.5 mU/L 
      (100 mug/day). Upon switching back to the tablet (100 mug/day), serum TSH increased 
      to 3.2 and 4.7 mU/L and then dropped to 2.7-3.0 mU/L when the dose was increased 
      to 125 mug/day. We also acutely evaluated the intestinal absorption of L-T4 by 
      administering 600 mug LT4 as a tablet or soft gel capsule while maintaining 
      pantoprazole. Pharmacokinetic indices showed better and faster absorption for the 
      soft gel capsule versus tablet (area under the curve [AUC]0-4h = 16,240 vs. 
      10,960 nmol/L x 4 hours, maximum absorption [Cmax] = 108 vs. 73 nmol/L, and time 
      of maximum absorption [Tmax] = 120 minutes vs. 180 minutes). CONCLUSION: 
      Confirming in vitro studies conducted by other authors, the soft gel capsule L-T4 
      is negligibly affected by changes in gastric pH compared to tablet L-T4.
FAU - Vita, Roberto
AU  - Vita R
AD  - Endocrinology, Department of Clinical and Experimental Medicine, University of 
      Messina, Messina, Italy.
FAU - Benvenga, Salvatore
AU  - Benvenga S
AD  - Endocrinology, Department of Clinical and Experimental Medicine, University of 
      Messina, Messina, Italy Master Program on Childhood, Adolescence & Women's 
      Endocrine Health, University of Messina, Messina, Italy Interdepartmental Program 
      of Molecular and Clinical Endocrinology and Women's Endocrine Health, A.O.U. 
      Policlinico G. Martino, Messina, Italy.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Endocr Pract
JT  - Endocrine practice : official journal of the American College of Endocrinology 
      and the American Association of Clinical Endocrinologists
JID - 9607439
EDAT- 2013/11/20 06:00
MHDA- 2013/11/20 06:01
CRDT- 2013/11/20 06:00
PHST- 2013/11/20 06:00 [entrez]
PHST- 2013/11/20 06:00 [pubmed]
PHST- 2013/11/20 06:01 [medline]
AID - S1530-891X(20)43252-5 [pii]
AID - 10.4158/EP13316.CR [doi]
PST - ppublish
SO  - Endocr Pract. 2014 Mar;20(3):e38-41. doi: 10.4158/EP13316.CR.