From the FDA Drug Label
The peak therapeutic effect of a given dose of levothyroxine sodium tablets may not be attained for 4 to 6 weeks. For adult patients with primary hypothyroidism, titrate until the patient is clinically euthyroid and the serum TSH returns to normal Titrate dosage by 12.5 to 25 mcg increments every 4 to 6 weeks, as needed until the patient is euthyroid.
The patient's TSH level is 1.18, which is within the normal range. No dose adjustment is necessary at this time. However, the patient should be monitored in 4 to 6 weeks to assess the peak therapeutic effect of the current dose and to determine if any adjustments are needed based on clinical response and laboratory parameters 1.
From the Research
No dose adjustment is needed at this time, as the TSH level of 1.18 while on 100 mcg of levothyroxine is within the normal range. The goal of levothyroxine therapy is to maintain TSH within the normal range, ideally in the lower half for most adults, as stated in the study by 2. Your current dose appears appropriate as it's keeping your TSH at a good level. Levothyroxine works by replacing the thyroid hormone your body needs, and dosing is individualized based on TSH response. Some key points to consider include:
- Taking your medication consistently at the same time each day, preferably 30-60 minutes before breakfast
- Avoiding taking it with calcium, iron supplements, or certain foods that can interfere with absorption
- Regular monitoring of TSH levels (typically every 6-12 months once stable) is recommended to ensure ongoing appropriate dosing, as mentioned in the study by 3. It's also important to note that treatment goals are age-dependent, with a 97.5 percentile (upper limit of normal) of 3.6 mIU/L for patients under age 40, and 7.5 mIU/L for patients over age 80, as stated in the study by 2. However, since the provided TSH level is within the normal range, no adjustment to the levothyroxine dose is necessary, and the patient can continue with their current treatment plan.