What should I watch for?
Visit your doctor or health care professional for regular checks on your progress. This medicine needs careful monitoring. Your doctor or health care professional may schedule regular blood tests.
Wear a medical ID bracelet or chain, and carry a card that describes your disease and details of your medicine and dosage times.
Do not change brands or dosage forms of this medicine without discussing the change with your doctor or health care professional.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
This medicine can cause unusual growth of gum tissues. Visit your dentist regularly. Problems can arise if you need dental work, and in the day to day care of your teeth. Try to avoid damage to your teeth and gums when you brush or floss your teeth.
Do not take antacids at the same time as this medicine. If you get an upset stomach and want to take an antacid or medicine for diarrhea, make sure there is an interval of 2 to 3 hours before or after you took your phenytoin.
The use of this medicine may increase the chance of suicidal thoughts or actions. Pay special attention to how you are responding while on this medicine. Any worsening of mood, or thoughts of suicide or dying should be reported to your health care professional right away.
Women who become pregnant while using this medicine may enroll in the North American Antiepileptic Drug Pregnancy Registry by calling 1-888-233-2334. This registry collects information about the safety of antiepileptic drug use during pregnancy.
Common and Rare Side Effects
Along with its needed effects, a medicine 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:
trouble with breathing, speaking, or swallowing
unsteadiness, trembling, or other problems with muscle control or coordination
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
Abdominal or stomach pain
blistering, peeling, or loosening of the skin
bloating of the abdomen or stomach
blood in the urine or stools
bloody, black, or tarry stools
cough or hoarseness
difficulty with moving
fever with or without chills
general feeling of discomfort or illness
general feeling of tiredness or weakness
irritation in the mouth
joint or muscle pain
lower back or side pain
nausea or vomiting
numbness, tingling, or pain in the hands or feet
painful or difficult urination
pinpoint red spots on the skin
red skin lesions, often with a purple center
red, irritated eyes
redness and swelling of the gums
sores, ulcers, or white spots on the lips or in the mouth
swollen, painful, or tender lymph glands in the neck, armpit, or groin
unusual bleeding or bruising
upper right abdominal or stomach pain
yellow eyes or skin
Some side effects 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:
uncontrolled eye movements
Incidence not known
Difficulty having a bowel movement (stool)
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
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.