Lithium Flashcards
Lithium has a What tire of therapeutic range?
very narrow therapeutic range (0.4-1.0 mmol/L)
Lithium has a long?
long plasma half-life being excreted primarily by the kidneys
Lithium toxicity maybe precipitated by?
dehydration
renal failure
drugs: diuretics (especially thiazides), ACE inhibitors/angiotensin II receptor blockers,
NSAIDs and
metronidazole.
Features of lithium toxicity
coarse tremor (a fine tremor is seen in therapeutic levels)
WEIGHT GAIN!
hyperreflexia
nausea/vomiting, diarrhoea
Management of lithium toxicity
mild-moderate toxicity may respond to volume resuscitation with normal saline
haemodialysis may be needed in severe toxicity
sodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion
Monitoring of patients on lithium therapy?
12 hours post-dose
after starting lithium - levels performed weekly and after each dose change
lithium blood - level should ‘normally’ be checked every 3 months
thyroid and renal function - should be checked every 6 months
How does lithium toxicity affect the kidneys ?
nephrotoxicity: polyuria, secondary to nephrogenic diabetes insipidus - DI - desensitises the kidney to respond to ADH
How does lithium toxicity affect the endocrine system
thyroid enlargement, may lead to hypothyroidism
hyperparathyroidism and resultant hypercalcaemia
ECG changes seen in lithium toxicity
ECG: T wave flattening/inversion
Lithium toxicity in the neurolgical system ?
idiopathic intracranial hypertension
acute confusion
seizure
coma
In what way does lithium toxicity affect the blood ?
leucocytosis
