The effects of carbamazepine on thyroid functions in childhood epilepsy

Abstract

Objective: To investigate the effects of carbamazepine therapy on thyroid function tests in children Methods: The carbamazepine group consisted of 58 children under observation for epilepsy, and the control group of 54 healthy children. Age of onset, length of drug use, drug dosage and laboratory parameters including free triiodothyronine (FT3), free thyroxin (FT4) and thyrotropin (TSH) were recorded. These data were then compared against those from the control group. Results: In the carbamazepine group, FT3 was 3.86 ± 0.43 pg/mL, FT4 was 1.15 ± 0.18 mg/dL and TSH: 2.58 ± 1.33 ml U/L. In the control group, FT3 was 4.13 ± 0.59 pg/mL, FT4 1.34 ± 0.13 mg/dL and TSH was 2.06 ± 0.89 ml U/L. No statistically significant difference between rates of subclinical hypothyroidism was determined between the two groups (p=0.196). Conclusion: Although, carbamazepine reduces thyroid hormone concentrations, rarely causes hypothyroidism.

Keywords

• Child, carbamazepine, thyroid function tests

Çocukluk çağı epilepsisinde karbamazepin\'in tiroid fonksiyonları üzerine etkisi

Abstract

Amaç: Çocuklarda karbamazepin tedavisinin tiroid fonsiyon testleri üzerine etkisini araştırmak Yöntem: Karbamazepin grubu epilepsi tanısıyla takip edilen elli sekiz çocuktan, kontrol grubu elli dört sağlıklı çocuktan oluşturuldu. Başlangıç yaşı, ilaç kullanım süresi, ilaç dozajı, ve serbest triiyodotironin (FT3), serbest tiroksin (FT4), tirotropin (TSH) parametrelerini içeren laboratuar parametreleri kaydedildi. Bu veriler kontrol grubuyla karşılaştırıldı. Bulgular: Karbamazepin grubunda sırasıyla, FT3 3,86 ± 0,43 pg/mL, FT4 1,15 ± 0,18 mg/dL TSH 2,58 ± 1,33 ml U/L olarak bulundu. Kontrol grubunda ise FT3 4,13 ± 0,59 pg/mL, FT4 1,34 ± 0,13 mg/dL ve TSH 2,06 ± 0,89 ml U/L olarak ölçüldü. İki grup arasında subklinik hipotiroidizm oranı istatistiksel olarak anlamlı değildi (p=0,196). Sonuç: Karbamazepin tiroid hormon konsantrasyonlarını düşürmesine rağmen nadiren hipotiroidizme neden olur.

Keywords

• Çocuk, karbamazepin, tiroid fonksiyon testleri

References

1. Wheless JW, Clarke DF, Arzimanoglou A, Carpenter D. Treatment of pediatric epilepsy: European expert opinion, 2007. Epileptic Disord 2007;9:353-412.
2. Leskiewicz M, Budziszewska B, Lason W. [Endocrine ef- fects of antiepileptic drugs]. Przegl Lek 2008;65:795-798.
3. Isojarvi JI, Pakarinen AJ, Ylipalosaari PJ, Myllyla VV: Se- rum hormones in male epileptic patients receiving anticon- vulsant medication. Arch Neurol 1990;47:670-676.
4. Pack A: Effects of Treatment on Endocrine Function in Pa- tients with Epilepsy. Curr Treat Options Neurol 2005;7:273- 280.
5. Ciampani M, Verrotti A, Chiarelli F. Sex hormones in pa- tients with epilepsy-hormonal changes in epileptic men and women taking antiepileptics. Horm Metab Res 2005;37:184-188.
6. Verrotti A, Basciani F, Morresi S, et al. Thyroid hormones in epileptic children receiving carbamazepine and valproic acid. Pediatr Neurol 2001;25:43-46.
7. Isojarvi JI, Pakarinen AJ, Myllyla VV. Thyroid function with antiepileptic drugs. Epilepsia 1992;33:142-148.
8. Aanderud S, Myking OL, Strandjord RE. The influence of carbamazepine on thyroid hormones and thyroxine binding globulin in hypothyroid patients substituted with thyroxine. Clin Endocrinol (Oxf) 1981;15:247-252.

9. Surks MI, Ortiz E, Daniels GH, et al. Subclinical thyroid disease: scientific review and guidelines for diagnosis and management. Jama 2004;291:228-238.
10. Torun E, Cindemir E, Özgen T, Öktem F. Subclinical hy- pothyroidism in obese children. Dicle Med J 2013;40:5-8.
11. Blank DW, Joffe RT. Effect of carbamazepine on thy- roid hormone measurement in vitro. Clin Chim Acta 1984;143:173-176.
12. Joffe RT, Gold PW, Uhde TW, Post RM. The effects of carbamazepine on the thyrotropin response to thyrotropin- releasing hormone. Psychiatry Res 1984;12:161-166.
13. Verrotti A, Laus M, Scardapane A, et al. Thyroid hor- mones in children with epilepsy during long-term admin- istration of carbamazepine and valproate. Eur J Endocrinol 2009;160:81-86.
14. Liewendahl K, Majuri H, Helenius T. Thyroid function tests in patients on long-term treatment with various anticonvul- sant drugs. Clin Endocrinol (Oxf) 1978;8:185-191.
15. Curran PG, DeGroot LJ. The effect of hepatic enzyme-in- ducing drugs on thyroid hormones and the thyroid gland. Endocr Rev 1991;12:135-150.
16. Harden CL. Therapeutic safety monitoring: what to look for and when to look for it. Epilepsia 2000;41:S37-44.
17. Connacher AA, Borsey DQ, Browning MC, et al. The effec- tive evaluation of thyroid status in patients on phenytoin, carbamazepine or sodium valproate attending an epilepsy clinic. Postgrad Med J 1987;63:841-845.
18. Larkin JG, Macphee GJ, Beastall GH, Brodie MJ. Thyroid hormone concentrations in epileptic patients. Eur J Clin Pharmacol 1989;36:213-216.
19. Yuksel D, Kırac FS, Yaylalı O, ID U. Prognostic role of Tc- 99m pertechnetate thyroid scintigraphy prior to fi xed-dose radioiodine therapy of toxic multinodular goiters. Turk J Med Sci 2011;41:981-988.
20. Surks MI, Sievert R. Drugs and thyroid function. N Engl J Med 1995;333:1688-1694.
21. Vainionpaa LK, Mikkonen K, Rattya J, et al. Thyroid func- tion in girls with epilepsy with carbamazepine, oxcarbaze- pine, or valproate monotherapy and after withdrawal of medication. Epilepsia 2004;45:197-203.
22. Isojarvi JI, Airaksinen KE, Mustonen JN, et at. Thyroid and myocardial function after replacement of carbamazepine by oxcarbazepine. Epilepsia 1995;36:810-816.
23. Simko J, Horacek J. Carbamazepine and risk of hypo- thyroidism: a prospective study. Acta Neurol Scand 2007;116:317-321.