Pharmacology Practice Test

A 34-year-old male (82 kg) with generalized anxiety disorder is started on propranolol 20 mg PO TID for performance anxiety. He has a history of asthma controlled with albuterol HFA 2 puffs q4–6h PRN; allergies: none. Vitals today: HR 58 bpm, BP 112/70 mmHg; labs: SCr 0.9 mg/dL (0.6–1.3). Which mechanism of action explains the most clinically important risk in this patient?

A 72-year-old female (54 kg) with hypothyroidism presents with palpitations and unintentional weight loss after a recent dose change. Current medications: levothyroxine 125 mcg PO daily (increased from 100 mcg 6 weeks ago), calcium carbonate 500 mg elemental calcium PO BID, and omeprazole 20 mg PO daily; allergies: none. Labs: TSH 0.05 mIU/L (0.4–4.0), free T4 2.3 ng/dL (0.8–1.8), SCr 0.9 mg/dL (0.6–1.1). What dose adjustment is required based on these lab values?