Lithium Flashcards
Organ lithium is excreted by
Kidneys
Congenital anomaly associated with maternal lithium use during pregnancy
Ebstein’s anomaly
Risk of Ebstein’s anomaly in the general population
1 in 20000
Risk of Ebstein’s anomaly when exposed to lithium in utero
1 in 1000
Structural abnormality in Ebstein’s anomaly
Prolapse of the tricuspid valve into the right ventricle
ECG seen in therapeutic lithium levels
Flat or inverted T waves
Contraindications to lithium use
Addison's disease Brugada syndrome Cardiac rhythm disorders including sick sinus syndrome Significant renal impairment Untreated hypothyroidism Hyponatraemia
Common side effects of lithium treatment at therapeutic levels
Nausea Polyuria/polydipsia Fine tremor Blurred vision Rash Dizziness Decreased appetite Metallic taste Causing and worsening psoriasis
Cause of polyuria and polydipsia in lithium use
ADH insensitivity
Long-term side effects of lithium use
Hypothyroidism or hyperthyroidism
Hypercalcaemia, hyperparathyroidism
Irreversible nephrogenic diabetes insipidus
Reduced eGFR
Features of lithium induced fine tremor
Symmetrical Largely in hands Similar to physiological tremor Typically occurs early in treatment More common in older patients Most apparent with intentional posture
Lithium levels to aim for in general circumstances
0.4-1.0mmol/L
Lithium levels to aim for if diabetes insipidus is a concern
0.4-0.8mmol/L
Cells affected in nephrogenic diabetes insipidus
Principle cells of the collecting duct
First line treatment for lithium induced nephrogenic diabetes insipidus
Amiloride
Treatments for lithium induced nephrogenic diabetes insipidus
Amiloride
Thiazide diuretics
Indomethacin
Desmopressin
Mechanism of action of amiloride in treating lithium associated nephrogenic diabetes insipidus
Blocks Na channels
Lithium cannot use Na channels to gain access to the principle cells of the collecting duct and cannot prevent water reabsorption there
Time lithium levels should be taken
12 hours post dose
Lithium levels to aim for in an acute manic episode
0.8-1.0