Lithium angiotensin-2 receptor antagonists

The authors proposed that this effect had occurred by reduced aldosterone secretion, an effect which is greater with ACE inhibitors than with angiotensin II receptor antagonists. In healthy volunteers losartan did not alter the fractional secretion of lithium (720), so presumably this patient had some susceptibility that caused the interaction. 

ANGIOTENSIN II RECEPTOR ANTAGONISTS LITHIUM Risk of lithium toxicity 1 excretion of lithium possibly due to 1 renal tubular reabsorption of sodium in proximal tubule Watch for lithium toxicity monitor lithium levels... 

Case reports describe lithium toxicity in patients given cande-sartan, losartan, valsartan, and possibly irbesartan. Other angiotensin II receptor antagonists would be expected to interact similarly. 

Not fully understood. It eould be that, as with the ACE inhibitors, angiotensin n reeeptor antagonists inhibit aldosterone secretion, resulting in increased sodium loss by the kidney tubules. This causes lithium retention and thus an increase in lithium levels. However, angiotensin II receptor antagonists have less effect on aldosterone than the ACE inhibitors, making a clinically significant interaction less likely. Animal studies show that ramipril, but not losartan, decreases the excretion of lithium by the kidney, which would support this idea. 

Patients on lithium should be aware of the symptoms of lithium toxicity and told to report them immediately should they occur. This should be reinforced when they are given angiotensin II receptor antagonists. As with ACE inhibitors , (p.lll2), the risk of lithium toxicity would be expected to increase when risk factors such as advanced age, renal insufficiency, heart failure and volume depletion are also present. 

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