Final answer:
A female on levothyroxine who starts taking OCPs may need a levothyroxine dosage adjustment due to the interaction between estrogen and thyroid-binding globulin, which can affect thyroid hormone levels.
Step-by-step explanation:
When a female on levothyroxine starts oral contraceptive pills (OCPs), it's important to understand the possible interactions. Levothyroxine, a synthetic thyroid hormone, may have its absorption affected by the estrogen in OCPs. The estrogen can increase the concentration of thyroid-binding globulin in the blood, leading to a decrease in the amount of levothyroxine available.
This can cause the patient's hypothyroid symptoms to return. Therefore, when starting OCPs, the patient's thyroid function should be monitored, and the dosage of levothyroxine may need to be adjusted to maintain euthyroid status.