Fosphenytoin Side Effects and Warnings

What are the precautions when taking this medicine?

• Wear disease medical alert identification.

• If you are 65 or older, use this medicine with caution. You could have more side effects.

• Follow laws about driving with a seizure condition.

• If you have been taking this medicine for several weeks, talk with healthcare provider before stopping. You may want to gradually withdraw this medicine.

• Check medicines with healthcare provider. This medicine may not mix well with other medicines.

• You may not be alert. Avoid driving, doing other tasks or activities until you see how this medicine affects you.

• Avoid alcohol (includes wine, beer, and liquor) or other medicines and natural products that slow your actions and reactions.

• Use birth control that you can trust to prevent pregnancy while taking this medicine.

• Birth control pills and other hormone-based birth control may not work to prevent pregnancy. Use another form of birth control while taking this medicine.

What are some possible side effects of this medicine?

• Feeling lightheaded, sleepy, having blurred vision, or a change in thinking clearly. Avoid driving, doing other tasks or activities that require you to be alert or have clear vision until you see how this medicine affects you. Confusion, being tired, mood changes, or slurred speech can occur too.

• Feeling dizzy. Rise slowly over several minutes from sitting or lying position. Be careful climbing.

• Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

• Constipation. More liquids, regular exercise, or a fiber-containing diet may help. Talk with healthcare provider about a stool softener or laxative.

Reasons to call healthcare provider immediately

• If you suspect an overdose, call your local poison control center or emergency department immediately.

• Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.

• Significant change in balance.

• Significant change in thinking clearly and logically.

• Severe nausea or vomiting.

• Feeling extremely tired or weak.

• If seizures are worse or different after starting medicine.

• Severe skin irritation.

• Any rash.

• No improvement in condition or feeling worse.