Lithium Flashcards
Give 2 examples of lithium formulations
- Lithium citrate
- Lithium carbonate
Why is it important to keep the patient on the same lithium formulation throughout treatment?
Contain different concentrations of lithium
On what basis is lithium prescribed?
By brand
What is the mechanism of action of lithium?
- Modifies the production and turnover of certain neurotransmitters, particularly serotonin, and may also block dopamine receptors.
- Alters concentrations of certain electrolytes, and may reduce thyroid activity
What are the routes of delivery of lithium?
PO
What are the indications for lithium?
- Acute episodes of mania and hypomania
- Recurrent depression where treatment with other anti-depressants has failed
- Bipolar affective disorder
- Control of aggressive behaviour or intentional self harm
What are the contraindications to lithium?
- Cardiac disease
- Personal or family history of Bruguda syndrome
- Untreated hypothyroidism
- Breastfeeding
Why is lithium contraindicated in untreated hypothyroidism?
Because lithium therapy can cause or exacerbate hypothyroidism
Why is lithium therapy contraindicated in breastfeeding?
Present in breastmilk
When should lithium be used with caution?
- Pregnancy
- Patients with low body sodium levels, e.g. dehydrated, taking low sodium diet
Why should lithium be used with caution in pregnancy?
Risk of fetal cardiac malformation (Epstein’s anomaly)
When should lithium be considered in pregnancy?
If benefit outweighs risk
What medications might lithium interact with to cause increased serum lithium concentration?
- Diuretics
- ACEi and ARBs
- NSAIDs
What medications might lithium interact with to cause reduce serum lithium concentrations?
Sodium chloride supplements
What medications might lithium interact with to cause QT prolongation?
- Amiodarone
- Venlafaxine
What medications might lithium interact with to cause an increased risk of tornadoes de pointes?
- Amiophylline
- Clarithryomycin
What medications might lithium interact with to cause an increased risk of serotonin syndrome?
- SSRIs
- MAOIs
Why is monitoring important with lithium?
Narrow therapeutic window and high toxicity risk
How should lithium be monitored?
- Monitor plasma lithium levels
- Renal function
- BP, weight, BMI
What should plasma lithium levels be?
0.4-1mmol/L
What should be done before starting lithium?
- Measure patients weight
- Check FBC, U&Es, TFTs, GFR, and obtain an ECG
When should lithium levels be checked?
1 week after starting, and every dose adjustment
How long after dose of lithium should levels be checked?
12 hours after last dose
How often should renal function be checked when the patient is on lithium?
Every 6 months
Why should renal function be checked every 6 months with lithium?
It is excreted by the kidneys
How often should BP, weight, and BMI be checked with lithium?
Annually
What should you do if the patients weight increases significantly during lithium treatment?
Consider weight management strategies to avoid adverse effects on patients health
What are the common side effects of lithium?
- Fine tremor
- Thirst
- Polyuria and diabetes insipidus
- Weight gain
- Metallic taste in mouth
- Hypothyroidism
- Goitre
What are the rare side effects of lithium?
Lithium toxicity
What are the signs of lithium toxicity?
- Anorexia
- Nausea
- Vomiting
- Nystagmus
- Coarse tremor
- Dysarthria
- Ataxia
- Seizure
- LoC
- Death
What patient counselling is required with lithium?
- Why and how to take lithium
- Stay hydrated and do not make dietary changes
- Non-compliance and risk of relapse
- Blood tests
- Signs of lithium toxicity
- Lithium treatment card
- Same brand
- Withdrawal
- Contraception
What should the patient be told about why they are starting lithium?
Mood stabiliser
How long should lithium therapy be continued for?
Should not start unless intention to continue for 3 years
Why should you not start lithium unless there is an intention to continue for at least 3 years?
Poor compliance may precipitate rebound mania or hypomania
What should the patient be told about how to take lithium?
Should be taken at the same time each day, and should not take more than prescribed dose
What should the patient be told about hydration and diet with lithium?
Important to maintain adequate fluid intake and avoid dietary changes that increase or decrease sodium intake
What should the patient be told about non-compliance with lithium?
Important patient does not stop taking lithium unless advised by a doctor, as if they stop taking suddenly there is risk of relapse
What should the patient be told about blood tests with lithium?
At start of treatment patient will have regular blood tests to ensure that level of lithium in blood is sufficient, as lithium has narrow therapeutic range and risk of toxicity if dose is incorrect
What should the patient be told about signs of lithium toxicity?
Should be aware of and vigilant for signs of lithium toxicity. Important to seek medical help immediately if lithium toxicity is suspected
What should the patient be told about a lithium treatment card?
Advise patient to carry a lithium treatment card and to inform any health professionals that they are treated by about their lithium therapy, including OTC medications
What should the patient be told about the same brand of lithium?
Important patient is maintained on same formation of lithium during treatment once they are stable. Advise patient to check brand of lithium they are prescribed every time they receive a new prescription from their doctor, and when they collect lithium at the pharmacy, to detect any prescription errors
What should the patient be told about withdrawal of lithium medication?
If lithium should be withdrawn, should be done gradually and under medical supervision
What should the patient be told about contraception with lithium?
Lithium is a teratogenic drug, so should be avoided in pregnant women. Sexually active females of child-bearing age are advised to use contraception
