@jdwandmew I have been on Dilantin since 1972 and over 51 years, never had spikes. In fact, I have trouble maintaining the level 10 which is where my doc would prefer me to be. My level is checked twice a year. My norm is about 7.5 to 9 and the doc said that this level is holding me. Might not be a bad idea to make a visit to your pharmacist and see if any meds and supplements you are taking would cause the Dilantin level to go up as it did. I think they may offer an opinion. Meanwhile, I understand and can appreciate your concern in lowering dosage. I'd start with the pharmacist. Good ljuck.