Absorption Kinetics of Levothyroxine Is Not Altered by Proton-pump Inhibitor Therapy

Introduction

Iodothyronines are widely prescribed drugs in developed countries. Several studies have shown a high prevalence of hypothyroidism in unselected populations [1]. In view of the frequency and comparatively small therapeutic range of thyroid hormones, interactions with other drugs are of considerable importance. The absorption of iodothyronines is known to be influenced by numerous substances, including antacid drugs [2] [3]. Sufficient gastric acidity has been assumed to be a prerequisite for effective iodothyronine resorption as a result [4]. However, whether thyroid replacement therapy is disturbed in patients treated with proton-pump inhibitors is still unknown, although this most effective form of acid inhibition is increasingly prescribed. To address this question, we have conducted a study in order to answer the question as to whether proton-pump inhibition affects levothyroxine resorption.

References

• 1 Canaris G J, Manowitz N R, Mayor G, Ridgway E C. .  Arch Intern Med. 2000;  160 526-534
• 2 Surks M I, Sievert R. .  New Engl J Med. 1995;  333 (25) 1688-1694
• 3 Sperber A D, Liel Y. .  Arch Intern Med. 1992;  152 183-184
• 4 Klein I, Danzi S. .  Thyroid. 2003;  13 1127-1132
• 5 Campbell N R, Hasinoff B B, Stalts H, Rao B, Wong N C. .  Ann Intern Med. 1992;  117 1010-1013
• 6 Singh N, Weisler S L, Hersman J M. .  Thyroid. 2001;  11 967-971
• 7 Berg J A, Mayor G H. .  J Clin Pharmacol. 1993;  33 1135-1140
• 8 Krehan A, Dittmar M, Hoppen A, Lichtwald K, Kahaly G J. .  Medizinische Klinik. 2002;  97 522-527
• 9 Evenepoel P, Claus D, Geypens B. et al . .  Aliment Pharmacol Ther. 1998;  12 1011-1019
• 10 Marcuard S P, Albernaz L, Khazanie P G. .  Ann Intern Med. 1994;  120 211-215
• 11 Hays M T. .  Endocrine Research. 1988;  14 203-224
• 12 Krenning E P, Docter R, Visser T J, Hennemann G. .  Acta medica Austriaca. 1988;  15 (Suppl 1) 15-17
• 13 Hennemann G, Docter R, Friesema E C, de Jong M, Krenning E P, Visser T J. .  Endocr Rev. 2001;  22 451-476
• 14 Harmon S M, Seifert C F. .  Ann Intern Med. 1993;  118 112-113