Di-Phen

Phenytoin is a prescription medication used to treat tonic-clonic (grand mal) seizures, complex partial (psychomotor or temporal lobe) seizures, and to prevent and treat seizures during or after brain surgery. Phenytoin belongs to a group of drugs called anticonvulsants, which lower abnormal electrical activity in the brain that causes seizures.

This medication comes in capsule, chewable tablet, and oral liquid forms. Phenytoin can be taken with or without food.

Common side effects of phenytoin include dizziness, confusion, and slurred speech. Alcohol should not be taken with phenytoin. Do not drive or operate machinery until you know how phenytoin will affect you.

Phenytoin is a prescription medicine used to treat tonic-clonic (grand mal), complex partial (psychomotor or temporal lobe) seizures, and to prevent and treat seizures that happen during or after brain surgery.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Do not stop taking phenytoin without first talking to your healthcare provider.

Stopping phenytoin suddenly can cause serious problems.

Phenytoin can cause serious side effects including:

Call a healthcare provider right away if you have any of these symptoms, especially if they are new, worse, or worry you:

• thoughts about suicide or dying
• attempts to commit suicide
• new or worse depression
• new or worse anxiety
• feeling agitated or restless
• panic attacks
• trouble sleeping (insomnia)
• new or worse irritability
• acting aggressive, being angry, or violent
• acting on dangerous impulses
• an extreme increase activity and talking (mania)
• other unusual changes in behavior or mood

Watch for early symptoms of suicidal thoughts and actions:

• Pay attention to any changes, especially sudden changes, in mood, behaviors, thoughts, or feelings.
• Keep all follow-up visits with your healthcare provider as scheduled.

Call your healthcare provider between visits as needed, especially if you are worried about symptoms.

Do not stop taking phenytoin without first talking to a healthcare provider.

• Stopping phenytoin suddenly can cause serious problems. Stopping a seizure medicine suddenly in a patient who has epilepsy can cause seizures that will not stop (status epilepticus).

Suicidal thoughts or actions can be caused by things other than medicines. If you have suicidal thoughts or actions, your healthcare provider may check for other causes.

• If you take phenytoin during pregnancy, your baby is at risk for serious birth defects.
• Birth defects may occur even in children born to women who are not taking any medicines and do not have other risk factors.
• If you take phenytoin during pregnancy, your baby is also at risk for bleeding problems right after birth. Your healthcare provider may give you and your baby medicine to prevent this.
• All women of child-bearing age should talk to their healthcare provider about using other possible treatments instead of phenytoin. If the decision is made to use phenytoin, you should use effective birth control (contraception) unless you are planning to become pregnant.
• Tell your healthcare provider right away if you become pregnant while taking phenytoin. You and your healthcare provider should decide if you will take phenytoin while you are pregnant.
• Pregnancy Registry: If you become pregnant while taking phenytoin, talk to your healthcare provider about registering with the North American Antiepileptic Drug Pregnancy Registry. You can enroll in this registry by calling 1-888-233-2334. The purpose of this registry is to collect information about the safety of antiepileptic drugs during pregnancy.

• swelling of your face, eyes, lips, or tongue
• trouble swallowing or breathing
• a skin rash
• hives
• fever, swollen glands, or sore throat that do not go away or come and go
• painful sores in the mouth or around your eyes
• yellowing of your skin or eyes
• unusual bruising or bleeding
• severe fatigue or weakness
• severe muscle pain
• frequent infections or an infection that does not go away

Call your healthcare provider right away if you have any of the symptoms listed above.

Do not take phenytoin if you:

• are allergic to phenytoin or any of the ingredients in phenytoin.
• have had an allergic reaction to CEREBYX (fosphenytoin), PEGANONE (ethotoin), or MESANTOIN (mephenytoin).

Do not drink alcohol while you take phenytoin without first talking to your healthcare provider. Drinking alcohol while taking phenytoin may change your blood levels of phenytoin which can cause serious problems.

Do not drive, operate heavy machinery, or do other dangerous activities until you know how phenytoin affects you. Phenytoin can slow your thinking and motor skills.

See "Drug Precautions".

Phenytoin may cause other serious side effects including:

• Softening of your bones (osteomalacia). This can cause broken bones.

Call your healthcare provider right away, if you have any of the symptoms listed above.

The most common side effects of phenytoin include:

• problems with walking and coordination
• slurred speech
• confusion
• dizziness
• trouble sleeping
• nervousness
• tremor
• headache
• nausea
• vomiting
• constipation
• rash

These are not all the possible side effects of phenytoin. For more information, ask your healthcare provider or pharmacist.

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your healthcare provider about all of the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your healthcare provider if you take:

• amiodarone (Cordarone, Pacerone)
• anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven)
• certain other antidepressants including amitriptyline (Elavil), amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), maprotiline, nortriptyline (Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
• chloramphenicol
• chlordiazepoxide (Librium, in Limbitrol)
• diazepam (Valium)
• digoxin (Lanoxin)
• disulfiram (Antabuse)
• doxycycline (Doryx, Monodox,Vibramycin, others)
• fluoxetine (Prozac, Sarafem, in Symbyax)
• furosemide (Lasix)
• H2 antagonists such as cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac)
• antacids that contain calcium (Maalox, Mylanta, Tums, others)
• hormonal contraceptives (birth control pills, patches, rings, or injections)
• hormone replacement therapy (HRT)
• isoniazid (in Rifamate, in Rifater)
• medications for mental illness and nausea
• other medications for seizures such as carbamazepine (Carbatrol, Equetro, Tegretol), ethosuximide (Zarontin), methsuximide (Celontin), phenobarbital, and valproic acid (Depakon, Depakene, Stavzor)
• methylphenidate (Daytrana, Concerta, Metadate, Ritalin)
• molindone (Moban)
• oral steroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), prednisolone, and prednisone (Deltasone)
• paroxetine (Paxil, Pexeva)
• quinidine
• reserpine (Serpalan)
• rifampin (Rimactane, in Rifamate, in Rifater)
• salicylate pain relievers such as aspirin, choline magnesium trisalicylate, choline salicylate (Arthropan), diflunisal (Dolobid), magnesium salicylate (Doan's, others), and salsalate (Argesic, Disalcid, Salgesic)
• sucralfate (Carafate)
• sulfa antibiotics
• theophylline (Theo-Dur)
• ticlopidine (Ticlid)
• tolbutamide
• trazodone
• vitamin D

This is not a complete list of phenytoin drug interactions. Ask your healthcare provider or pharmacist for more information.

See "Drug Precautions".

Tell your doctor if you are pregnant or plan to become pregnant. Phenytoin may harm the unborn baby and could be dangerous to a pregnant woman. You and your doctor will need to decide if the benefits of phenytoin outweigh the risks. If you are taking phenytoin and you become pregnant, call your doctor right away.

Tell your doctor if you are breastfeeding. Phenytoin is excreted in human breast milk. 

Stopping phenytoin suddenly can cause serious problems. Stopping a seizure medicine suddenly in a patient who has epilepsy can cause seizures that will not stop (status epilepticus).

All women of child-bearing age should talk to their healthcare provider about using other possible treatments instead of phenytoin. If the decision is made to use phenytoin, you should use effective birth control (contraception) unless you are planning to become pregnant.

Do not drink alcohol while you take phenytoin without first talking to your healthcare provider. Drinking alcohol while taking phenytoin may change your blood levels of phenytoin which can cause serious problems.

Your doctor will monitor your phenytoin blood levels and may change your dose accordingly.