European Journal of Biomedical and Pharmaceutical Sciences

DRUG INDUCED THYROID DISORDERS – A REVIEW

Dr. P. Kishore*, V. Ravali, K. Veena Kawal and D. Sudheer Kumar

ABSTRACT

Thyroid axis is particularly prone to interactions with wide variety of drugs and natural substances every year. These substances affect every aspect of thyroid physiology and hormone pharmacology and their interactions lead to different form of thyroid disorders majority includes hypothyroidism, thyrotoxicosis and goiter. Drugs which cause both hypothyroidism and hyperthyroidism include amiodarone, lithium and tyrosine kinase inhibitors such as sunitinib and sorafenib. The reported incidence of amiodarone induced hypothyroidism varies widely ranging from as high as 13 % in countries like UK and USA (high dietary iodine intake countries) and thyrotoxicosis 2-9.6 %. Prevalence of TKI induced hypothyroidism was 36%. Two to four months after the initiation of sorafenib, 18 % of patients were presented with hypothyroidism and 3% of patients’ exhibit hyperthyroidism. In UK, the prevalence of hypothyroidism and hyperthyroidism in patients who were on lithium therapy was found to be 10.3 % and 0-1% respectively. The decision about management of drug induced thyroid dysfunctions whether to treat or not, depends on the degree of thyroid dysfunction, patient’s age and in particular, on the underlying condition for which those drugs were prescribed. Clinical Pharmacist play a major role in diagnosis and management of thyroid disorders with the aim is to attenuate symptoms and also to restore normal levels of thyroid hormones and TSH for better patient care. Clinical Pharmacist can improve the health of the patients by avoiding drug induced toxicities.

Keywords: Thyroid, Amiodarone, Tyrosine Kinase Inhibitors, Lithium.