The concurrent use of
lithium and
verapamil can be uneventful, but neurotoxicity, bradycardia, choreoathetosis, and decreases in
serum lithium levels have been seen in a few patients. An acute parkinsonian
syndrome and marked psychosis has been seen in at least one patient taking
lithium with
diltiazem.
The adverse reactions cited above contrast with other reports describing unevent- ful concurrent use. This unpredictability emphasises the need to monitor the effects closely where it is thought appropriate to give
lithium with these calcium- channel blockers.