Evaluation of covariates using population pharmacokinetics approach for dose individualization of levothyroxine in patients with post thyroidectomy and¹³¹i ablation therapy

The current therapy for patients with thyroid cancer is total or near to total thyroidectomy with Radio Iodine treatment. Subsequent to the thyroidectomy the patients are on Levothyroxine as a supplement therapy to maintain the Thyroid hormone levels.Levothyroxine has been considered as a narrow therapeutic index drug. In Thyroid cancer patients, radio-iodine ablation procedure causes hypothyroid state which will be further elongated by the administration of sub optimal doses and hyperthyroid symptoms with higher doses. The current study was conducted to evaluate the covariates influencing the drug concentration of levothyroxine in our target population, i.e Patient with Papillary carcinoma, undergone total thyroidectomy followed by¹³¹I ablation and on Levothyroxine.