The
plasma levels of
diltiazem,
isradipine and
nifedipine are increased by
cimetidine and it may be necessary to reduce their dosages. High doses of
cimetidine may increase the bioavailability of lercanidipine. Although studies suggest no important inter- actions occur between nicardipine or
nisoldipine and
cimetidine, the manufacturers advise caution.
Plasma felodipine, lacidipine,
nimodipine, and nitrendipine levels are also increased but this does not seem to be clinically significant.
Monitor concurrent use. If adverse effects (such as hypotension, dizziness, flushing and palpitations) become troublesome decrease the calcium-channel blocker dose.