skip to main content

Levothyroxine and iron — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

EasyDrug InteractionsLevothyroxine and ironGPhC CRA

A patient prescribed levothyroxine in the morning has started ferrous sulfate for anaemia. She asks if they can be taken together with breakfast. What is the most important interaction to flag?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Reduced levothyroxine absorption if taken together

Iron salts can bind levothyroxine and reduce its absorption. The doses should be separated, and thyroid function may need review if timing has changed. Taking levothyroxine consistently on an empty stomach supports stable control. This is a clinically common counselling interaction.

Reference: BNF; NICE CKS