system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 30-year-old woman presents to a medical clinic for a routine check-up. She gained about 5 kg (11 lb) since the last time she weighed herself 3 months ago. She also complains of constipation and sensitivity to cold. She also noticed her hair appears to be thinning. The patient started to use combined oral contraceptives a few months ago and she is compliant. On physical examination, the temperature is 37.0°C (98.6°F), the blood pressure is 110/70 mm Hg, the pulse is 65/min, and the respiratory rate is 14/min. The laboratory results are as follows:
Thyroxine (T4), total 25 ug/dL
Thyroxine (T4), free 0.8 ng/dL
TSH 0.2 mU/L
Which of the following is the main mechanism of action of the drug that caused her signs and symptoms?
assistant
Inhibition of hormones in the pituitary gland