Do NOT use Dilantin if:

• you are allergic to any ingredient in Dilantin or to another hydantoin (eg, fosphenytoin).

Some medical conditions may interact with Dilantin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a blood disease (eg, porphyria), liver disease, diabetes, or a history of lymph gland problems
• if you are in very poor heath
• if you drink alcohol or have a history of alcohol abuse
• if you have been tested and know whether or not you have a gene type called HLA-B*1502.

Some medicines may interact with Dilantin. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Many other prescription and nonprescription medicines (eg, used for asthma, blood thinning, diabetes, infections, inflammation, aches and pains, high blood pressure, heart problems, high cholesterol, birth control, hormone replacement, mental or mood problems, sleep seizures), multivitamin products, and herbal or dietary supplements (eg, herbal teas, coenzyme Q10, garlic, ginseng, ginkgo, St. John's wort) may interact with Dilantin, increasing the risk of side effects. Ask your doctor or pharmacist if you are unsure if any of your medicines might interfere with Dilantin.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Dilantin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Dilantin may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Dilantin with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Check with your doctor before you drink alcohol while you are taking Dilantin. Alcohol may increase or decrease the amount of medicine in your blood.
• Do not change brands or dose forms (eg, tablets, suspension, injection) of Dilantin without talking with your doctor.
• Do not take more than the recommended dose without checking with your doctor.
• Proper dental care is important while you are taking Dilantin. Brush and floss your teeth and visit the dentist regularly.
• Dilantin may raise your blood sugar. High blood sugar may make you feel confused, drowsy, or thirsty. It can also make you flush, breathe faster, or have a fruit-like breath odor. If these symptoms occur, tell your doctor right away.
• There have been reports of lymph node problems, including cancer, in patients who take Dilantin. It is not known if Dilantin may be the cause. Contact your doctor right away if you develop swollen lymph nodes, fever, rash, dark urine, stomach pain, or yellowing of the eyes or skin.
• Tell your doctor or dentist that you take Dilantin before you receive any medical or dental care, emergency care, or surgery.
• Hormonal birth control (eg, birth control pills) may not work as well while you are using Dilantin. To prevent pregnancy, use an extra form of birth control (eg, condoms).
• Patients who have a certain gene type called HLA-B*1502 may have an increased risk for serious skin reactions from Dilantin. This gene type is found most commonly in Asian patients. Tell your doctor if you have been tested and know whether or not you have the HLA-B*1502 gene type. Discuss any questions or concerns with your doctor.
• Dilantin may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Dilantin.
• Lab tests, including blood phenytoin levels, may be performed while you use Dilantin. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Dilantin with caution in the elderly; they may be more sensitive to its effects.
• Women who take Dilantin may experience an increase in seizure activity if they become pregnant. Discuss any questions or concerns with your doctor. If you think you may be pregnant, contact your doctor.
• Pregnancy and breast-feeding: Dilantin may cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Dilantin while you are pregnant. Dilantin is found in breast milk. Do not breastfeed while taking Dilantin.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Constipation; dizziness; headache; mild nervousness; nausea; trouble sleeping; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bone pain; butterfly-shaped rash on the face; clumsiness or unsteadiness; confusion; dark urine; delirium; high blood sugar (flushing; fruit-like breath odor; increased thirst, hunger, or urination; rapid breathing); mental or mood changes; numbness or tingling of the hands or feet; red, swollen, blistered, or peeling skin; signs of infection (eg, chills, fever, sore throat); slurred speech; stomach pain; swollen lymph nodes; swollen or tender gums; tremor; unusual bruising or bleeding; unusual eye movements; unusual muscle movements; yellowing of the skin or eyes.

 This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.