No treatment will fully and specifi

No treatment will fully and specifically correct the defect. Most important is not to intervene with the sole purpose of normalizing the TH levels. Sinus tachycardia can be controlled with the β-adrenoceptor blocking agent, atenolol. Prenatal diagnosis and counseling are particularly important in families whose affected members show evidence of growth or mental retardation. Fortunately, in most subjects with RTH, the partial tissue resistance to TH is adequately compensated for by an increase in the endogenous supply of TH and, thus, treatment is not required. This is not the case in patients with limited thyroidal reserve due to prior ablative therapy. In these patients, the serum TSH level can be used as a guideline for hormone dosage. Occasionally, the compensation is incomplete and requires the judicious administration of supraphysiologic doses of the hormone. In children, particular attention must be paid to growth, bone maturation, and mental development. It is suggested that TH be given in incremental doses. The basal metabolic rate (BMR), nitrogen balance, and serum SHBG should be monitored at each dose, and bone age and growth in the longer term. Development of a catabolic state is an indication of overtreatment.