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Dilantin

Last reviewed on RxList: 11/28/2016
Dilantin Side Effects Center

Last reviewed on RxList 9/16/2016

Dilantin (phenytoin) is an anti-epileptic drug, also called an anticonvulsant, used to control seizures. Dilantin is available in generic form. Common side effects of Dilantin include:

  • headache,
  • nausea,
  • vomiting,
  • constipation,
  • dizziness,
  • spinning sensation,
  • drowsiness,
  • slurred speech,
  • loss of balance or coordination,
  • swollen or tender gums,
  • sleep problems (insomnia),
  • nervousness,
  • tremors, or
  • rash.

Patients may be started on one 100-mg Dilantin Extended Oral Capsule three times daily. For most adults, the maintenance dosage is one capsule three to four times a day. The initial pediatric dose is 5 mg/kg/day in two or three equally divided doses, with dosage individualized to a maximum of 300 mg daily. Daily maintenance dosage is usually 4 to 8 mg/kg. Dilantin may interact with stomach acid reducers, sedatives, antidepressants, estrogen hormone replacement, phenothiazines, disulfiram, methylphenidate, sulfa drugs, carbamazepine, sucralfate, molindone, phenobarbital, valproic acid, divalproex sodium, steroids, antibiotics, digoxin, furosemide, or theophylline. Tell your doctor all medications you use. During pregnancy, Dilantin should be used only when prescribed. It may harm a fetus. Since untreated seizures are a serious condition that can harm both a pregnant woman and the fetus, do not stop taking this medication unless directed by your doctor. Hormonal birth control may not work if taken with this medication. Discuss birth control with your doctor. This medication passes into breast milk. Consult your doctor before breastfeeding. Abrupt withdrawal of Dilantin in epileptic patients may precipitate status epilepticus.

Our Dilantin (phenytoin) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Dilantin Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. You may be more likely to have an allergic reaction if you are African-American.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, depression, anxiety, or if you feel agitated, hostile, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have a serious side effect such as:

  • fever, swollen glands, body aches, flu symptoms;
  • skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;
  • upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
  • chest pain, irregular heart rhythm, feeling short of breath;
  • confusion, nausea and vomiting, swelling, rapid weight gain, urinating less than usual or not at all;
  • new or worsening cough with fever, trouble breathing;
  • tremor (uncontrolled shaking), restless muscle movements in your eyes, tongue, jaw, or neck;
  • patchy skin color, red spots, or a butterfly shaped skin rash over your cheeks and nose (worsens in sunlight); or
  • severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Less serious side effects may include:

  • slurred speech, loss of balance or coordination;
  • swollen or tender gums; or
  • headache, dizziness, nervousness, or sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Dilantin (Phenytoin)

Dilantin Professional Information

SIDE EFFECTS

The most notable signs of toxicity associated with the intravenous use of this drug are cardiovascular collapse and/or central nervous system depression. Hypotension does occur when the drug is administered rapidly by the intravenous route. The rate of administration is very important; it should not exceed 50 mg per minute in adults, and 1- 3 mg/kg/min (or 50 mg per minute, whichever is slower) in pediatric patients.

Body As a Whole

Allergic reactions in the form of rash and rarely more serious forms (see Skin and Appendages paragraph below) and DRESS (see WARNINGS) have been observed. Anaphylaxis has also been reported.

There have also been reports of coarsening of facial features, systemic lupus erythematosus, periarteritis nodosa, and immunoglobulin abnormalities.

Cardiovascular

Severe cardiovascular events and fatalities have been reported with atrial and ventricular conduction depression and ventricular fibrillation. Severe complications are most commonly encountered in elderly or critically ill patients (see WARNINGS).

Nervous System

The most common adverse reactions encountered with phenytoin therapy are nervous system reactions and are usually dose-related. Reactions include nystagmus, ataxia, slurred speech, decreased coordination, somnolence, and mental confusion. Dizziness, vertigo, insomnia, transient nervousness, motor twitchings, paresthesia, and headaches have also been observed. There have also been rare reports of phenytoin induced dyskinesias, including chorea, dystonia, tremor and asterixis, similar to those induced by phenothiazine and other neuroleptic drugs.

A predominantly sensory peripheral polyneuropathy has been observed in patients receiving long-term phenytoin therapy.

Digestive System

Acute hepatic failure, toxic hepatitis, liver damage, nausea, vomiting, constipation, enlargement of the lips, and gingival hyperplasia.

Skin and Appendages

Dermatological manifestations sometimes accompanied by fever have included scarlatiniform or morbilliform rashes. A morbilliform rash (measles-like) is the most common; other types of dermatitis are seen more rarely. Other more serious forms which may be fatal have included bullous, exfoliative or purpuric dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis (see WARNINGS section). There have also been reports of hypertrichosis.

Local irritation, inflammation, tenderness, necrosis, and sloughing have been reported with or without extravasation of intravenous phenytoin (see WARNINGS).

Hematologic and Lymphatic System

Hematopoietic complications, some fatal, have occasionally been reported in association with administration of phenytoin. These have included thrombocytopenia, leukopenia, granulocytopenia, agranulocytosis, and pancytopenia with or without bone marrow suppression. While macrocytosis and megaloblastic anemia have occurred, these conditions usually respond to folic acid therapy. Lymphadenopathy, including benign lymph node hyperplasia, pseudolymphoma, lymphoma, and Hodgkin's Disease have been reported (see WARNINGS).

Special Senses

Altered taste sensation including metallic taste.

Urogenital

Peyronie's disease

Read the entire FDA prescribing information for Dilantin (Phenytoin)

Related Resources for Dilantin

Read the Dilantin User Reviews »

© Dilantin Patient Information is supplied by Cerner Multum, Inc. and Dilantin Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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