A 40 yrs old female who is known case of ischemic heart disease [IHD] is diagnosed having hypothyroidism. Which of the following would be most appropriate line of management for her? (AIPG 2010)
|A||Start Levothyroxine at low dose|
|B||Do not start Levothyroxine|
|D||Thyroid extract is a better option|
Start Levothyroxine at low dose
Hypothyroid and CAD (AIPG 2011)
In the elderly, especially patients with known coronary artery disease, the starting dose of levothyroxine should be the lowest starting dose i.e. 12.5–25 g/d with similar increments every 2–3 months until TSH is normalized.
Reason for this is – in hypothyroidism the metabolic rate is low. So myocardial oxygen demand is low. With sudden treatment with high doses, heart rate will increase and that will lead to coronaryischemia. (Ref. Hari-18th ed., Pg-2922)
Extra Edge: Hypothyroidism in pregnancy
1). Most pregnant women with primary hypothyroidism require an increase in the dose of thyroxine of some 50 μg daily.
2). Explanation for this phenomenon is increase in serum thyroxine-binding globulin concentration during pregnancy, resulting in a decrease in serum free thyroid hormone concentrations which cannot be compensated for by thyroidal secretion.