Lithium Flashcards
Where is lithium excreted?
kidneys
Is lithium metabolised?
no
Is lithium associated with Ebsteins anomaly?
It was but now found not to be true
What are the contraindications for lithium?
Addison’s disease
Brugada syndrome
Cardiac disease associated with rhythm disorders
Clinically significant renal impairment
Untreated or untreatable hypothyroidism
Low sodium levels, including people that are dehydrated and those on low-sodium diets
What are side effects of lithium?
Nausea
Polyuria/polydipsia
Fine tremor
Rash/dermatitis
Blurred vision
Dizziness
Decreased appetite
Metallic taste
Drowsiness
Diarrhoea
Muscle weakness
How can nausea be avoided with lithium?
Twice daily dosing or sustained release
What advice could you give to someone regarding nausea due to lithium?
That it tends to improve over time
What type of tremor results from lithium?
What can be used to help?
Who is it more common in?
When does it tend to happen?
- Symmetrical
Indistinguishable from essential tremor - Propranolol
- Older age
- Early in treatment, but can happen at any time
What types of rash does lithium cause?
Acne
Psoriasis
Does lithium tend to cause weightgain or weight loss?
Weight gain
What conditions is lithium associated with causing?
Hypothyroidism and hyperthyroidism
Hypercalcemia/hyperparathyroidism (lithium increases renal calcium reabsorption and independently stimulates parathyroid hormone release)
Irreversible nephrogenic diabetes insipidus
Reduced GFR (chronic kidney disease)
What are symptoms of nephrogenic DI?
Polyuria
Dehydration
Thirst
Polydipsia
Explain how lithium causes nephrogenic DI
Urine concentration is mediated by the principal cells of the collecting duct. Lithium can cause dysregulation of the principal cells in the short-term and cell loss in the long-term.
This dysfunction of principal cells renders them unresponsive to ADH (vasopressin) which induces expression of water transport proteins in the late distal tubule and collecting duct to increase water reabsorption.
What are treatment options for nephrogenic DI
- Stop lithium
- Keep levels within 0.4-0.8
- Once daily dose at bedtime rather than twice daily
- Amiloride - K sparing diuretic, blocks sodium channels which lithium uses to gain access to principal cells
- Thiazide diuretics
- Indomethacin
- Desmopressin
What range of lithium concentration is recommended for acute mania or those who have previously relapsed?
0.8-1
What are risk factors of lithium toxicity?
Drugs altering renal function
Decreased circulating volume (great heat, sauna)
Infections - esp w D+V
Fever
Decreased oral intake
Renal insufficiency
Nephrogenic diabetes insipidus
what drugs can increase the risk of lithium toxicity?
NSAIDS
THiazide diuretics
ACE inhibitors
What are features of lithium toxicity?
GI symptoms (nausea, vomiting, diarrhea, and cramping abdominal pains)
Neuro symptoms (coarse tremor, confusion, seizures, dystonia, hyperreflexia, nystagmus and ataxia)
Tremor is more irregular, more widespread and more severe than fine tremor
What scale can be used to assess for toxicity?
AMDISEN
What must be checked before prescribing lithium?
Renal function
ECG
TFTs
FBC and BMI
Give NICE recommendations for lithium monitoring
weekly until stable then every 3 months
Give Maudsley recommendation for lithium monitoring
every 6 months
What are recommendations from BNF for monitoring lithium?
Weekly until stable, then every 3 months for first year then every 6 months after
How often should thyroid and renal function be checked?
6 monthly
