Lithium toxicity has been seen in individual patients given candesartan, losartan,
valsartan and possibly
irbesartan. Other angiotensin II
receptor antagonists would be expected to interact similarly. The risk of
lithium toxicity would be expected to increase when risk factors such as advanced age,
renal impairment, heart failure and volume depletion are also present.
Even though the interaction appears rare, patients should have their
lithium levels monitored to avoid a potentially severe adverse interaction. The development of the interaction may be delayed (up to 7 weeks seen) so that weekly monitoring of
lithium levels for several weeks has been advised. Patients taking
lithium should be aware of the
symptoms of
lithium toxicity and told to immediately report them should they occur. This should be reinforced when they are given angiotensin II
receptor antagonists.