A 72-year-old client with coronary artery disease is started on levothyroxine 25 mcg daily for newly diagnosed hypothyroidism. The client takes calcium carbonate with dinner and ferrous sulfate with lunch. Which instructions should the nurse include? Select exactly 3 responses.

Quick answer
Take it on an empty stomach, keep iron (and calcium) about 4 hours apart, and report chest pain or a racing heartbeat.

Why this is correct
Food, calcium, and iron reduce levothyroxine absorption. In an older client with coronary artery disease, thyroid hormone raises myocardial oxygen demand, so dosing starts low, rises slowly, and new angina or tachycardia must be reported.

Easy analogy or mental picture
Think of the heart as an old engine: you raise the throttle a notch at a time and listen for knocking before going faster.

Memory hook
Empty stomach, four-hour gap, go slow with an old heart.

NCLEX decision rule
When a teaching item adds age, heart disease, or other medicines, the key applies those details; generic rules alone are not enough.

Why the other choices are wrong
A TSH check at 1 week ignores the 6-to-8-week steady state. Taking it with breakfast sounds like good consistency teaching, but food at breakfast cuts absorption. A pulse-based hold rule belongs to drugs such as digoxin; for levothyroxine, new tachycardia or chest pain is reported, not self-managed by skipping doses.