Lithium
A mood stabilizer used to treat mania and prevent relapse in bipolar disorder; it has a narrow therapeutic range.
Also called lithium carbonate (salt used in tablets and capsules) or lithium citrate (salt used in liquid forms).
Drug card
- Class
- Mood stabilizer
- How it works
- Altering nerve-cell signaling, such as inositol recycling; exact action unknown
- Used for
- Acute mania and mixed episodes in bipolar I disorder
- Maintenance treatment of bipolar I disorder
- Recurrent depression other drugs have not helped (UK)
- Known for
- Fine hand tremor
- Passing a lot of urine and thirst (nephrogenic DI)
- Underactive thyroid (hypothyroidism)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does lithium work?
Lithium's mood-stabilizing mechanism is unknown. Proposed actions include depleting inositol by blocking its recycling, altering cAMP signaling and neuronal sodium exchange, and changing neurotransmitter release. It is not metabolized: the kidneys filter it and reabsorb most of it, so anything that lowers sodium or dehydrates the body can push its level up.
Uses
What is lithium used for?
- Acute mania and mixed episodes in bipolar I disorder
- Maintenance treatment of bipolar I disorder
- Recurrent depression other drugs have not helped (UK)
Side effects
Side effects of lithium
- Fine hand tremorKnown for
- Passing a lot of urine and thirst (nephrogenic DI)Known for
- Underactive thyroid (hypothyroidism)Known for
- Toxicity: vomiting, coarse tremor, ataxia, confusionSerious
- Nausea and diarrhea, mostly early on
- Weight gain
- Chronic kidney disease with long-term useSerious
- Raised calcium and overactive parathyroid glands
- Overactive thyroid, less often
- Metallic taste
- Low sodium (hyponatremia)Serious
- Possible heart defects (Ebstein's anomaly) in pregnancySerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Narrow therapeutic range: toxicity can occur close to therapeutic levels, so regular blood lithium levels guide dosing.
- Recheck levels after starting or changing diuretics, NSAIDs or ACE inhibitors and ARBs, and in dehydration or on a low-salt diet.
- Check kidney and thyroid function and calcium before starting and regularly during treatment.
- It can unmask Brugada syndrome: avoid it in people with the syndrome or a suspicious family history.
Good to know: An element given as a salt, not a designed molecule; because toxic levels lie just above therapeutic ones, treatment depends on regular blood tests.
Remember it
A way to remember it
LMNOP
- L
- Levels checked: narrow therapeutic range
- M
- Movement: fine hand tremor
- N
- Nephrogenic diabetes insipidus: polyuria and thirst
- O
- hypOthyroidism
- P
- Pregnancy: possible heart defects (Ebstein's anomaly)
A mnemonic widely used in teaching
Its class
Lithium
How lithium stabilizes mood is not known. It acts on several signaling systems in nerve cells: it depletes cellular inositol by blocking its recycling, alters cAMP signaling and sodium exchange across membranes, and changes neurotransmitter release, and it may help protect neurons. It is not metabolized but filtered by the kidneys, and its toxic level lies close to its therapeutic one.
Easily mixed up with valproate and second-generation antipsychotics.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Lithium carbonate capsules: label (DailyMed)
- Lithium (NHS)
- Lithium Carbonate (NCI Thesaurus)
- Lithium (NCI Thesaurus)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Psychosis, mood and ADHD
Lithium is one of 9 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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