There are numerous commonly used substances which can affect the central control, synthesis and peripheral effects of thyroid hormones. Question 25 from the second paper of 2013 asks specifically for the effects of amiodarone, propranolol, glucocorticoids and opiates. Those either inhibition the peripheral conversion T4 to T3 (first two) or inhibit TSH secretion (second two). But there are many other thyroid-influencing drugs.
This is an attempt to create a referenced list of such substances, ordered according to their effect on thyroid function.
| TSH | Inhibition of release | |
| Stimulation of release |
Antipsychotics, especially amisulpiride |
|
| T3 and T4 synthesis | Inhibition of thyroid synthetic function |
Thiouracils (eg. propylthiouracil) Imidazoles (eg. carbimazole) |
| Stimulation of thyroid synthetic function |
Inorganic iodine (eg. potassium iodide) - if you have a normal thyroid gland Iodinated contrast agents (high iodine content) |
|
| T3 and T4 release from the thyroid gland | Inhibition of release |
Inorganic Iodine (eg. potassium iodide) Iodinated contrast agents (high iodine content) |
| Stimulation of release |
Amiodarone (by thyroiditis) |
|
| Conversion of T4 into T3 | Inhibition of conversion | |
| Stimulation of conversion |
Selenium (a cofactor in T4-T3 conversion; selenium supplementation will not result in a supranormal T3 level - merely a return to normal) |
|
| Transport of thyroid hormones by binding to thyroid-binding globulin (TBG) |
Increased TBG levels (thus decreased free T3) |
|
|
Decreased TBG levels (thus increased free T3) |
Niacin (nicotinic acid) |
|
| Increased binding of T4 to TBG | ||
| Decreased binding of T4 to TBG (by displacement) |
Aspirin and salicylates in general Frusemide (and ethacrynic acid) |
|
| Clearance of T4 | Increased clearance | |
| Decreased clearance |
Glycosylflavones in millet-rich diets of the poor in the developing world, or in the weird hippies who think it is healthy to emulate them. |
The same table, reorganised to reflect the difference in the clinical picture arising from exposure to these drugs:
Hypothyroidism |
Hyperthyroidism |
||
| Inhibition of TSH release | Stimulation of TSH release |
Antipsychotics, especially amisulpiride |
|
| Inhibition of thyroid synthetic function |
Thiouracils (eg. propylthiouracil) Imidazoles (eg. carbimazole) |
Stimulation of thyroid synthetic function |
Inorganic iodine (eg. potassium iodide) - if you have a normal thyroid gland Iodinated contrast agents (high iodine content) |
| Inhibition of T3 and T4 release from the thyroid gland |
Inorganic Iodine (eg. potassium iodide) Iodinated contrast agents (high iodine content) |
Stimulation of T3 and T4 release from the thyroid gland |
Amiodarone (by thyroiditis) |
| Inhibition of conversion of T4 into T3 | Stimulation of conversion of T4 into T3 |
Selenium (a cofactor in T4-T3 conversion; selenium supplementation will not result in a supranormal T3 level - merely a return to normal) |
|
|
Increased TBG levels (thus decreased free T3) |
Decreased TBG levels (thus increased free T3) |
Niacin (nicotinic acid) |
|
| Increased binding of T4 to TBG | Decreased binding of T4 to TBG (by displacement) |
Aspirin and salicylates in general Frusemide (and ethacrynic acid) |
|
| Increased clearance of T4 | Decreased clearance of T4 |
Glycosylflavones in millet-rich diets of the poor in the developing world, or in the weird hippies who think it is healthy to emulate them. |
|
As always, good old UpToDate has a summary of this topic, which is both detailed and concise. There is even a nice table of drugs which cause changes in TFTs.
For the freegan, Life In The Fast Lane have a characteristically brilliant summary of drugs which affect thyroid function.
Baruah, M. P., and R. J. Singh. "Effects of drugs on thyroid function." Thyroid Research and Practice 9.1 (2012): 3.
Sharp, Burt, et al. "The role of opiates and endogenous opioid peptides in the regulation of rat TSH secretion." Brain research 219.2 (1981): 335-344.
Scanlon, M. F., et al. "Dopamine is a physiological regulator of thyrotrophin (TSH) secretion in normal man." Clinical endocrinology 10.1 (1979): 7-15.
Gründer, Gerhard, et al. "Neuroendocrine response to antipsychotics: effects of drug type and gender." Biological psychiatry 45.1 (1999): 89-97.
Lee, Edwin, et al. "Effect of acute high dose dobutamine administration on serum thyrotrophin (TSH)." Clinical endocrinology 50.4 (1999): 487-492.
Wilber, John F., and Robert D. Utiger. "The effect of glucocorticoids on thyrotropin secretion." Journal of Clinical Investigation 48.11 (1969): 2096.
Maini, Carlo L., Rosa Sciuto, and Anna Tofani. "TSH suppression by octreotide in differentiated thyroid carcinoma." Clinical endocrinology 40.3 (1994): 335-339.
Monaco, F., et al. "Effects of propylthiouracil and methylmercaptoimidazole on thyroglobulin synthesis." Acta endocrinologica 93.1 (1980): 32-36.
Das, Debasis, Gouriprasanna Roy, and Govindasamy Mugesh. "Antithyroid drug carbimazole and its analogues: synthesis and inhibition of peroxidase-catalyzed iodination of L-tyrosine." Journal of medicinal chemistry 51.22 (2008): 7313-7317.
Sedvall, Göran, Britta Jönsson, and Ulla Petterson. "Evidence of an altered thyroid function in man during treatment with lithium carbonate." Acta Psychiatrica Scandinavica 44.S207 (1969): 59-67.
Martino, Enio, et al. "The Effects of Amiodarone on the Thyroid 1." Endocrine Reviews 22.2 (2001): 240-254.
de Savary, Nicola, Richard Lee, and Bijay Vaidya. "Severe hypothyroidism after thalidomide treatment." Journal of the Royal Society of Medicine 97.9 (2004): 443-443.
Wolff, J., and I. L. Chaikoff. "Plasma inorganic iodide as a homeostatic regulator of thyroid function." Journal of Biological Chemistry 174.2 (1948): 555-564.
Wartofsky, Leonard, Bernard J. Ransii, and Sidney H. Ingbar. "Inhibition by iodine of the release of thyroxine from the thyroid glands of patients with thyrotoxicosis." Journal of Clinical Investigation 49.1 (1970): 78.
Shilo, Shmuel, and Harry J. Hirsch. "Iodine-induced hyperthyroidism in a patient with a normal thyroid gland." Postgraduate medical journal 62.729 (1986): 661-662.
Roti, Elio, and Ettore Degli Uberti. "Iodine excess and hyperthyroidism." Thyroid11.5 (2001): 493-500.
Rhee, Connie M., et al. "Association between iodinated contrast media exposure and incident hyperthyroidism and hypothyroidism." Archives of internal medicine 172.2 (2012): 153-159.
Heyma, Paul, et al. "D-propranolol and DL-propranolol both decrease conversion of L-thyroxine to L-triiodothyronine." British medical journal 281.6232 (1980): 24.
WILLIAMS, DONALD E., et al. "Acute effects of corticosteroids on thyroid activity in Graves' disease." The Journal of Clinical Endocrinology & Metabolism41.2 (1975): 354-361.
Oppenheimer, Jack H., Harold L. Schwartz, and Martin I. Surks. "Propylthiouracil inhibits the conversion of L-thyroxine to L-triiodothyronine: an explanation of the antithyroxine effect of propylthiouracil and evidence supporting the concept that triiodothyronine is the active thyroid hormone."Journal of Clinical Investigation 51.9 (1972): 2493.
Beckett, G. J., et al. "Inhibition of hepatic deiodination of thyroxine is caused by selenium deficiency in rats." Biochem. J 248 (1987): 443-447.
Abdulrahman, Randa M., et al. "Sorafenib-induced hypothyroidism is associated with increased type 3 deiodination." Journal of Clinical Endocrinology & Metabolism 95.8 (2010): 3758-3762.
AIN, KENNETH B., YUICHI MORI, and SAMUEL REFETOFF. "Reduced Clearance Rate of Thyroxine-Binding Globulin (TBG) with Increased Sialylation: A Mechanism for Estrogen-Induced Elevation of Serum TBG Concentration*."The Journal of Clinical Endocrinology & Metabolism 65.4 (1987): 689-696.
Mamby, Celai C., Richard R. Love, and Kristine E. Lee. "Thyroid function test changes with adjuvant tamoxifen therapy in postmenopausal women with breast cancer." Journal of clinical oncology 13.4 (1995): 854-857.
EnglIsh, Trevor N., D. Ruxton, and C. J. Eastman. "Abnormalities in thyroid function associated with chronic therapy with methadone." Clinical chemistry34.11 (1988): 2202-2204.
CHAN, VIVIAN, CHRISTINA WANG, and ROSE TT YEUNG. "Effects of heroin addiction on thyrotrophin, thyroid hormones and prolactin secretion in men."Clinical endocrinology 10.6 (1979): 557-565.
AIN, KENNETH B., and SAMUEL REFETOFF. "Relationship of Oligosaccharide Modification to the Cause of Serum Thyroxine-Binding Globulin Excess*." The Journal of Clinical Endocrinology & Metabolism 66.5 (1988): 1037-1043.
Daly, R. C., et al. "Neuroendocrine and behavioral effects of high-dose anabolic steroid administration in male normal volunteers." Psychoneuroendocrinology28.3 (2003): 317-331.
Gamstedt, Anders, et al. "Corticosteroids and thyroid function." Acta Medica Scandinavica 205.1‐6 (1979): 379-383.
Mohamed Shakir, K. M., et al. "Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state." Mayo Clinic Proceedings. Vol. 70. No. 6. Elsevier, 1995.
Männistö, Tuija. MATERNAL THYROID FUNCTION DURING PREGNANCY. Diss. UNIVERSITY OF OULU, 2011.
Larsen, P. R. "Salicylate-induced increases in free triiodothyronine in human serum: evidence of inhibition of triiodothyronine binding to thyroxine-binding globulin and thyroxine-binding prealbumin." Journal of Clinical Investigation 51.5 (1972): 1125.
Stockigt, J. R., et al. "Interaction of Furosemide with Serum Thyroxine Binding Sites: In Vivo and in Vitro Studies and Comparison with Other Inhibitors*." The Journal of Clinical Endocrinology & Metabolism 60.5 (1985): 1025-1031.
SCHATZ, DOUGLAS L., et al. "Influence of Heparin on Serum Free Thyroxine 1." The Journal of Clinical Endocrinology & Metabolism 29.8 (1969): 1015-1022.
Faber, J., et al. "The Effects of Phenytoin (Diphenylhydantoin) on the Extrathyroidal Turnover of Thyroxine, 3, 5, 3′-Triiodothyronine, 3, 3′, 5′-Triiodothyronine, and 3′, 5′-Diiodothyronine in Man*." The Journal of Clinical Endocrinology & Metabolism 61.6 (1985): 1093-1099.
Christensen, Hanne R., et al. "Influence of rifampicin on thyroid gland volume, thyroid hormones, and antipyrine metabolism." Acta endocrinologica 121.3 (1989): 406-410.
De Luca, F., et al. "Changes in thyroid function tests induced by 2 month carbamazepine treatment in L-thyroxine-substituted hypothyroid children."European journal of pediatrics 145.1-2 (1986): 77-79.
CAVALIERI, RALPH R., LILLIAN C. SUNG, and CHARLES E. BECKER. "Effects of phenobarbital on thyroxine and triiodothyronine kinetics in Graves' disease." The Journal of Clinical Endocrinology & Metabolism 37.2 (1973): 308-316.
GAITAN, EDUARDO, et al. "Antithyroid and Goitrogenic Effects of Millet: Role of C-Glycosylflavones*." The Journal of Clinical Endocrinology & Metabolism68.4 (1989): 707-714.
LAMBERT, MICHEL J., et al. "Are Selective Increases in Serum Thyroxine (T4) due to Iodinated Inhibitors of T4 Monodeiodination Indicative of Hyperthyroidism?*." The Journal of Clinical Endocrinology & Metabolism 55.6 (1982): 1058-1065.