Mood stabilisers: lithium levels: practice question

A Psychiatry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Psychiatry · Mood stabilisers: lithium levels

Sample item

The generally accepted therapeutic serum lithium range is:

A0.1 to 0.3 mmol/LB1.5 to 2.5 mmol/LC0.6 to 1.2 mmol/LD3.0 to 4.0 mmol/L

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. 0.6 to 1.2 mmol/L

Lithium has a narrow therapeutic index, with target levels of about 0.6 to 1.2 mmol/L (lower for maintenance, higher for acute mania). Samples are taken about 12 hours after the last dose.

Option by option

A. 0.1 to 0.3 mmol/L
Levels this low are subtherapeutic.
B. 1.5 to 2.5 mmol/L
Levels above 1.5 mmol/L are toxic.
C. 0.6 to 1.2 mmol/L (correct)
Correct. The usual range is 0.6 to 1.2 mmol/L.
D. 3.0 to 4.0 mmol/L
Such levels are life-threatening.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Psychiatry question

What is the answer to this Psychiatry question?

The best answer is C, 0.6 to 1.2 mmol/L. Lithium has a narrow therapeutic index, with target levels of about 0.

Why is "0.1 to 0.3 mmol/L" not the answer?

Levels this low are subtherapeutic.

Why is "1.5 to 2.5 mmol/L" not the answer?

Levels above 1.5 mmol/L are toxic.

Why is "3.0 to 4.0 mmol/L" not the answer?

Such levels are life-threatening.

What concept does this question test?

It tests Mood stabilisers: lithium levels in Psychiatry. 6 to 1.2 mmol/L (lower for maintenance, higher for acute mania). Samples are taken about 12 hours after the last dose.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Mood stabilisers: lithium levels?

Learn each diagnosis by its core features and its first-line treatment. Then use the flashcards and the other Psychiatry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.