A ACEinhibitorscanraiselithiumlevels,andinsomeindividuals2-to4-foldincreases
have occurred. Cases of
lithium toxicity have been reported in patients given
captopril, enalapril or
lisinopril (and possibly perindopril). One analysis found an increased relative risk of 7.6 for
lithium toxicity requiring hospitalisation, in elderly patients, newly started on an ACE inhibitor. Risk factors for this interaction seem to be poor
renal function, heart failure, volume depletion, and increased age.
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, and so it has been advised that
lithium levels should be monitored weekly for several weeks. Patients taking
lithium should be aware of the
symptoms of
lithium toxicity (e.g. increased nausea, weakness, fine tremor, drowsiness, lethargy) and told to immediately report them should they occur. This should be reinforced when they are given
ACE inhibitors.