This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Imseis, R. E. Articles by Vanmiddlesworth, N. R. Search for Related Content PubMed PubMed Citation Articles by Imseis, R. E. Articles by Vanmiddlesworth, N. R.

Pretreatment with Propylthiouracil But Not Methimazole Reduces the Therapeutic Efficacy of Iodine-131 in Hyperthyroidism

Department of Medicine, Division of Endocrinology (R.E.I., L.V.), Department of Radiology (J.D.M.), Department of Preventive Medicine (A.J.B.), Department of Physiology and Biophysics (L.V., N.R.V.), University of Tennessee, Memphis, Tennessee 38163

Address all correspondence and requests for reprints to: L. Vanmiddlesworth, Ph.D., M.D., University of Tennessee, 894 Union Avenue, Memphis, Tennessee 38163. E-mail: lvanmid{at}physio1.utmem.edu

Ninety-three hyperthyroid patients were treated with 1 dose of iodine-131 (¹³¹I) during the past 10 years. Thirty-three were pretreated with propylthiouracil (PTU), 22 with methimazole (MMI), and 38 received no antithyroid drugs (ATD). ATD were discontinued 5–55 days before ¹³¹I therapy in three fourths of the cases and more than 4 months before therapy in one fourth of the cases. The frequency of cures in the 3 groups, 6–8 months after radioiodine therapy, was retrospectively studied. The cure rate among those who discontinued PTU for 5–55 days before ¹³¹I was significantly reduced (24%), compared with those who discontinued MMI for the same duration (61%) or those who received no ATD (66%). When PTU was discontinued for more than 4 months, the cure rate was similar to those who received no ATD.

It is concluded that if ATD are used as initial therapy for hyperthyroidism, then PTU (but not MMI) may reduce the therapeutic efficacy of subsequent ¹³¹I. The reduction in cure rate was observed even when PTU was discontinued for as long as 55 days before ¹³¹I therapy.

To our knowledge, this is the first report to compare, in one study, the effects of pretreatment with PTU and MMI on ¹³¹I therapy.

This article has been cited by other articles:

				I. R. McDougall and A. Iagaru Reply: Antithyroid Drugs and Radioiodine and the Absence of Evidence J. Nucl. Med., August 1, 2007; 48(8): 1403b - 1404. [Full Text] [PDF]

				M. A Walter, M. Briel, M. Christ-Crain, S. J Bonnema, J. Connell, D. S Cooper, H. C Bucher, J. Muller-Brand, and B. Muller Effects of antithyroid drugs on radioiodine treatment: systematic review and meta-analysis of randomised controlled trials BMJ, March 10, 2007; 334(7592): 514 - 514. [Abstract] [Full Text] [PDF]

				A. Iagaru and I. R. McDougall Treatment of Thyrotoxicosis J. Nucl. Med., March 1, 2007; 48(3): 379 - 389. [Abstract] [Full Text] [PDF]

				S. J. Bonnema, F. N. Bennedbaek, A. Veje, J. Marving, and L. Hegedus Continuous Methimazole Therapy and Its Effect on the Cure Rate of Hyperthyroidism Using Radioactive Iodine: An Evaluation by a Randomized Trial J. Clin. Endocrinol. Metab., August 1, 2006; 91(8): 2946 - 2951. [Abstract] [Full Text] [PDF]

				B. E Jensen, S. J Bonnema, and L. Hegedus Glucocorticoids do not influence the effect of radioiodine therapy in Graves' disease Eur. J. Endocrinol., July 1, 2005; 153(1): 15 - 21. [Abstract] [Full Text] [PDF]

				S. J. Bonnema, F. N. Bennedbaek, A. Veje, J. Marving, and L. Hegedus Propylthiouracil before 131I Therapy of Hyperthyroid Diseases: Effect on Cure Rate Evaluated by a Randomized Clinical Trial J. Clin. Endocrinol. Metab., September 1, 2004; 89(9): 4439 - 4444. [Abstract] [Full Text] [PDF]

				D. S. Cooper Antithyroid Drugs in the Management of Patients with Graves' Disease: An Evidence-Based Approach to Therapeutic Controversies J. Clin. Endocrinol. Metab., August 1, 2003; 88(8): 3474 - 3481. [Full Text] [PDF]

				D. D Streetman and U. Khanderia Diagnosis and Treatment of Graves Disease Ann. Pharmacother., July 1, 2003; 37(7): 1100 - 1109. [Abstract] [Full Text] [PDF]

				J. E. Kalinyak and I. R. McDougall How Should the Dose of Iodine-131 Be Determined in the Treatment of Graves' Hyperthyroidism? J. Clin. Endocrinol. Metab., March 1, 2003; 88(3): 975 - 977. [Full Text] [PDF]

				F. Bogazzi, L. Bartalena, A. Campomori, S. Brogioni, C. Traino, F. De Martino, G. Rossi, F. Lippi, A. Pinchera, and E. Martino Treatment with Lithium Prevents Serum Thyroid Hormone Increase after Thionamide Withdrawal and Radioiodine Therapy in Patients with Graves' Disease J. Clin. Endocrinol. Metab., October 1, 2002; 87(10): 4490 - 4495. [Abstract] [Full Text] [PDF]

				E. K. Alexander and P. R. Larsen American Board of Internal Medicine. 2002 Certification Examination in Endocrinology, Diabetes, and Metabolism J. Clin. Endocrinol. Metab., March 1, 2002; 87(3): 1073 - 1077. [Abstract] [Full Text] [PDF]

				V. A. Andrade, J. L. Gross, and A. L. Maia The Effect of Methimazole Pretreatment on the Efficacy of Radioactive Iodine Therapy in Graves' Hyperthyroidism: One-Year Follow-Up of a Prospective, Randomized Study J. Clin. Endocrinol. Metab., August 1, 2001; 86(8): 3488 - 3493. [Abstract] [Full Text] [PDF]

				A. Allahabadia, J. Daykin, M. C. Sheppard, S. C. L. Gough, and J. A. Franklyn Radioiodine Treatment of Hyperthyroidism--Prognostic Factors for Outcome J. Clin. Endocrinol. Metab., August 1, 2001; 86(8): 3611 - 3617. [Abstract] [Full Text] [PDF]

				H. B. Burch, B. L. Solomon, D. S. Cooper, P. Ferguson, N. Walpert, and R. Howard The Effect of Antithyroid Drug Pretreatment on Acute Changes in Thyroid Hormone Levels after 131I Ablation for Graves' Disease J. Clin. Endocrinol. Metab., July 1, 2001; 86(7): 3016 - 3021. [Abstract] [Full Text] [PDF]

				P. M. Kadmon, R. B. Noto, C. M. Boney, G. Goodwin, and P. A. Gruppuso Thyroid Storm in a Child following Radioactive Iodine (RAI) Therapy: A Consequence of RAI Versus Withdrawal of Antithyroid Medication J. Clin. Endocrinol. Metab., May 1, 2001; 86(5): 1865 - 1867. [Abstract] [Full Text]

				A. P. Weetman Graves' Disease N. Engl. J. Med., October 26, 2000; 343(17): 1236 - 1248. [Full Text] [PDF]

				K. A. Woeber Update on the Management of Hyperthyroidism and Hypothyroidism Arch Fam Med, August 1, 2000; 9(8): 743 - 747. [Full Text] [PDF]

				K. A. Woeber Update on the Management of Hyperthyroidism and Hypothyroidism Arch Intern Med, April 24, 2000; 160(8): 1067 - 1071. [Abstract] [Full Text] [PDF]

				K. A. Woeber The Year in Review: The Thyroid Ann Intern Med, December 21, 1999; 131(12): 959 - 962. [Abstract] [Full Text] [PDF]

				O. Sabri, M. Zimny, G. Schulz, M. Schreckenberger, P. Reinartz, K. Willmes, and U. Buell Success Rate of Radioiodine Therapy in Graves' Disease: The Influence of Thyrostatic Medication J. Clin. Endocrinol. Metab., April 1, 1999; 84(4): 1229 - 1233. [Abstract] [Full Text]

				F. Bogazzi, L. Bartalena, S. Brogioni, G. Scarcello, A. Burelli, A. Campomori, L. Manetti, G. Rossi, A. Pinchera, and E. Martino Comparison of Radioiodine with Radioiodine plus Lithium in the Treatment of Graves' Hyperthyroidism J. Clin. Endocrinol. Metab., February 1, 1999; 84(2): 499 - 503. [Abstract] [Full Text]