Problem:
Your patient is a 67 year old male with atrial fib, iron deficiency anemia, osteoporosis, hypothyroidism and essential tremors. He lives alone. His renal function is normal and has had stable rhythms. He takes amiodarone 400mg daily for his a-fib, Levothyroxine 137 mcg daily for his hypothyroidism. Ferrous sulfate 325mg tid for anemia, Oscal 500 w/D bid for his osteoporosis, primidone was recently increased to 300mg daily for his essential tremors. He loves making wooden puzzles for his grandchildren. His TSH level was 20.13 at his last appointment. Using drug references, please provide appropriate scenarios for drug interactions that could have caused this TSH level, what actions should be taken for patient safety, how many weeks would be appropriate to retest the TSH and what patient education should be discussed.