Some, but not all studies have shown that antacids
(containing aluminium, calcium or magnesium) do not usually interact to a clinically relevant extent with phenytoin
. However, in some instances antacids
have reduced phenytoin serum
levels and this may have been responsible for some loss of seizure control
in a few patients.
Concurrent use need not be avoided but if there is any hint that an epileptic patient is being affected by this interaction, separating the dosages by 2 to 3 hours may minimise the effects.