Drug Interactions between mephenytoin and sodium phenylbutyrate / taurursodiol

Mephenytoin levels may decrease when the suspension is given with enteral feedings. This could lead to a loss of seizure control. You could interrupt the feeding for 2 hours before and after the mephenytoin dose. Alternatively, you may give the mephenytoin suspension diluted in water and flush the tube with water after administration. These would make it easier for your body to absorb the medication. However, this still may not entirely avoid the interaction and may not always be feasible. You should have your mephenytoin levels checked upon starting and stopping of enteral feedings. In addition, using mephenytoin together with food may alter the effects of mephenytoin. Contact your doctor if you experience worsening of seizure control or symptoms of toxicity, including twitching eye movements, slurred speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, feeling light-headed, fainting, and slow or shallow breathing. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Ask your doctor before making any changes to your therapy.

Food may affect the absorption of sodium phenylbutyrate. A high-fat, high-calorie meal (approximately 800 to 1000 calories; 500 to 600 calories from fat, 250 calories from carbohydrate, 150 calories from protein) has been shown to reduce the absorption of sodium phenylbutyrate, although it is unknown what impact this may have on the overall effectiveness of the medication. The manufacturer recommends taking sodium phenylbutyrate before a meal or snack. This is especially important if you weigh less than 70 kg (approximately 154 pounds). Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.