The thiazide and related
diuretics can cause a rapid rise in
lithium levels, which may lead to
lithium toxicity. This interaction has been seen with bendroflumethiazide,
chlorothiazide, chlortalidone,
hydrochlorothiazide and
indapamide, and potentially occurs with hydroflumethiazide. Other
thiazides and related
diuretics are expected to behave similarly.
Lithium levels should be closely monitored if a thiazide is started or stopped. One UK manufacturer recommends an initial
lithium dose reduction, but this does not seem to be in line with most other recommendations. Patients taking
lithium should be aware of the
symptoms of
lithium toxicity and told to report them immediately should they occur.