How soon after taking phenytoin will my symptoms improve?

After taking phenytoin, you will be able to judge how quickly the medication works for you as you experience fewer episodes of seizures. You should see your doctor regularly to talk about your progress. After the first seven to ten days, you should have a blood test. This will help your doctor determine how well the dosage is working for you. If you experience any side effects, such as easy bruising, abnormal bleeding, or breathing difficulty, inform your doctor immediately.