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Phenytoin Sodium Side Effects

Generic name: phenytoin

Medically reviewed by Drugs.com. Last updated on Jun 30, 2024.

Note: This document provides detailed information about Phenytoin Sodium Side Effects associated with phenytoin. Some dosage forms listed on this page may not apply specifically to the brand name Phenytoin Sodium.

Applies to phenytoin: oral capsule extended release, oral suspension, oral tablet chewable.

Other dosage forms:

Serious side effects of Phenytoin Sodium

Along with its needed effects, phenytoin (the active ingredient contained in Phenytoin Sodium) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking phenytoin:

More common

  • decreased coordination
  • mental confusion
  • nervousness
  • slurred speech
  • trouble with breathing, speaking, or swallowing
  • unsteadiness, trembling, or other problems with muscle control or coordination

Rare

  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • shakiness and unsteady walk
  • shakiness in the legs, arms, hands, or feet
  • sticking out of the tongue
  • trembling or shaking of the hands or feet
  • twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual facial expressions

Incidence not known

  • bleeding gums
  • blistering, peeling, or loosening of the skin
  • blisters, hives, itching, skin rash
  • bloating of the abdomen or stomach
  • blood in the urine or stools
  • bloody, black, or tarry stools
  • chest pain or discomfort
  • chills
  • cough
  • dark urine
  • diarrhea
  • difficulty with moving
  • fainting spells
  • fever with or without chills
  • general feeling of discomfort or illness
  • hair loss
  • headache
  • high fever
  • hoarseness
  • irritation in the mouth
  • joint or muscle pain
  • light-colored stools
  • lightheadedness or dizziness
  • lower back or side pain
  • muscle stiffness
  • nausea
  • numbness, tingling, or pain in the hands or feet
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • redness and swelling of the gums
  • slow or irregular heartbeat
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stomach pain
  • swollen, painful, or tender lymph glands in the neck, armpit, or groin
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • upper right abdominal or stomach pain
  • vomiting
  • weight loss
  • yellow eyes or skin

Other side effects of Phenytoin Sodium

Some side effects of phenytoin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • trouble sleeping
  • uncontrolled eye movements

Incidence not known

  • difficulty having a bowel movement
  • enlarged lips
  • feeling of constant movement of self or surroundings
  • increased hair growth on the forehead, back, arms, or legs
  • pain of the penis on erection
  • sensation of spinning

For healthcare professionals

Applies to phenytoin: compounding powder, injectable solution, oral capsule, oral capsule extended release, oral suspension, oral tablet chewable.

Cardiovascular

Dermatologic

Endocrine

Gastrointestinal

Genitourinary

Hematologic

Hepatic

Hypersensitivity

Immunologic

Local

Metabolic

Musculoskeletal

Nervous system

Ocular

Other

Renal

Respiratory

Psychiatric

References

1. (2001) "Product Information. Dilantin (phenytoin)." Parke-Davis

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Pharmaceutical Society of Australia (2006) APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp

Further information

Phenytoin Sodium side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.