Phenbarb Tablet is a combination of two medicines used in the treatment and prevention of epilepsy (seizures). It controls seizures by decreasing the abnormal and excessive activity of the nerve cells in the brain. Phenbarb Tablet is taken with or without food. However, it is advised to take it at the same time each day as this helps to maintain a consistent level of medicine in the body. Take this medicine in the dose and duration advised by your doctor as its long-term use may be habit-forming. Do not skip any doses, but if you miss a dose of this medicine, take it as soon as you remember. Finish the full course of treatment even if you feel better. Stopping the medication without talking to the doctor may cause rebound seizures. Some common side effects of this medicine include nausea, vomiting, vertigo, and double vision. It may also cause dizziness and sleepiness. So, do not drive or do anything that requires mental focus until you know how this medicine affects you. Let your doctor know if you experience severe skin rashes, especially accompanied by fever after taking this medicine. You may be asked for a regular blood tests to check the level of drug in the blood. Your doctor should also know about all other medicines you are taking as many of these may make this medicine less effective or change the way it works. Inform your doctor if you are pregnant, planning pregnancy or breastfeeding. Be careful if you are using birth control pills as this medicine may interfere with the working of contraceptives. Let your doctor know if you are taking medicine for diabetes, as it can raise the blood sugar level.