 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST] . How to use Dilantin Read the Medication Guide provided by your pharmacist before you start taking phenytoin and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Take this medication by mouth as directed by your doctor, usually once a day or in divided doses. You may take it with food if stomach upset occurs. Take this medication with a full glass (8 ounces or 240 milliliters) of water unless your doctor directs you otherwise. Swallow the capsules whole. Do not use the capsules if discolored. Use this medication regularly in order to get the most benefit from it. It is important to take all doses on time to keep the amount of medicine in your body at a constant level. Remember to use it at the same time(s) each day. Dosage is based on your medical condition and response to therapy. Antacids and nutritional tube-feeding (enteral) products may decrease the absorption of phenytoin. Do not take these products at the same time as your phenytoin dose. Separate liquid nutritional products at least 1 hour before and 1 hour after your phenytoin dose, or as directed by your doctor. Do not stop taking this medication </s>