Phenytoin

Description

Phenytoin is an anticonvulsant which is used to control and/or prevent seizures that begin after surgery. Take this medicine at the same time regularly for a better seizure control. Do not take this medicine if you are suffering from impaired liver function.

Side effects

Major & minor side effects for Phenytoin

  • Decreased coordination
  • Nervousness
  • Unsteadiness
  • Shaking of hands or feet
  • Unusual facial expressions
  • Trouble sleeping
  • Uncontrolled eye movements
  • Yellow colored eyes or skin
  • Skin rash
  • Headache

Uses of Phenytoin

What is it prescribed for?

  • Seizures
  • Status Epilepticus
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Concerns

Commonly asked questions

  • Onset of action
    The peak effect of this medicine can be observed in 1.5 to 3 hours for an immediate release tablet and 4 to 12 hours for an extended release tablet.
  • Duration of effect
    The effect of this medicine lasts for an average duration of 2 to 3 days for an oral dose and 1 to 2 days for an intravenous dose.
  • Safe with alcohol?
    Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
  • Is it habit forming?
    No habit forming tendency has been reported
  • Usage in pregnancy?
    This medicine is not recommended for pregnant women.
  • Usage while breast-feeding?
    This medicine is known to be excreted in the breastmilk. It is not recommended in breastfeeding women unless absolutely necessary.

Allergy

Not recommended in the patients with known allergy to Phenytoin.
Warnings for special population

Pregnancy

This medicine is not recommended for pregnant women.

Breast-feeding

This medicine is known to be excreted in the breastmilk. It is not recommended in breastfeeding women unless absolutely necessary.
General warnings

Withdrawal symptoms

Do not stop suddenly taking this medicine without informing the doctor. It may precipitate the status epilepticus in patients with known history of epilepsy.

Suicidal behavior

This medicine should be used with caution in patients with known history of depression. It may increase the risk of suicidal thoughts. Educate the patient's caretakers about these symptoms. Inform the doctor if the symptoms persist.

Skin reactions

This medicine may cause serious skin reactions like toxic epidermal necrolysis and Stevens-Johnson syndrome. Seek immediate medical treatment if any symptoms of skin reactions appear

Impaired liver function

This medicine should be used with caution in patients with the liver injury. Close monitoring of liver function tests is necessary. Discontinue the treatment if the symptoms persist.

Effects on bone

This medicine is known to decrease the bone density and may increase the risk of osteoporosis and osteomalacia. Inform the doctor if you have any bone disorder. Close monitoring of Vit-D levels and radiological findings is necessary.

Missed Dose

Take the missed dose as soon as you remember. If it’s almost time for your next dose, skip the missed dose. Do not double your dose to make up for the missed dose.

Overdose

Seek emergency medical treatment or contact the doctor if any symptoms of the overdose like uncontrolled body movements, slurred speech appear.
All drugs interact differently for person to person. You should check all the possible interactions with your doctor before starting any medicine.
Interaction with Alcohol

Description

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.

Instructions

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
Interaction with Medicine

Metoclopramide

Voriconazole

Warfarin

Ethinyl Estradiol

Disease interactions

Blood disorders

Phenytoin may lower the blood cell count and may lead to a fatal condition. Close monitoring of blood cell count is necessary. Inform the doctor if you have any blood disorder. An alternate class of medicine may be considered based on the clinical condition.

Cardiotoxicity

Phenytoin is not recommended in the patients with heart disorders. Inform the doctor if you have a history of heart disease. An alternate class of medicine should be considered based on the clinical condition.
Food interactions
Information not available.
Lab interactions
Information not available.
Take Phenytoin as advised by your doctor. Do not take this medicine with calcium supplements or antacids due to the decrease in the absorption. Do not take in larger amounts than advised. Consult the doctor if you experience any undesirable effects. Do not stop taking the medicine without consulting the doctor as it may cause seizures.
Miscelleneous

Can be taken with or without food, as advised by your doctor

To be taken as instructed by doctor

May cause sleepiness

How it works
It works by decreasing the abnormal electrical activity in the brain by inhibiting the repetitive firing of neurons.
Legal Status

Approved

Approved

Approved

Approved

Classification

Category

Hydantoin anticonvulsants

Schedule

Schedule H

[Internet]. 2017 [cited 21 April 2017]. Available from:

https://www.medicines.org.uk/emc/medicine/30860

DailyMed - phenytoin sodium capsule [Internet]. Dailymed.nlm.nih.gov. 2017 [cited 21 April 2017]. Available from:

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5362ea50-38a4-48b4-a85b-d634c3d8b91a#section-1

Prescribing medicines in pregnancy database [Internet]. Therapeutic Goods Administration (TGA). 2017 [cited 21 April 2017]. Available from:

https://www.tga.gov.au/prescribing-medicines-pregnancy-database#searchname

[Internet]. Toxnet.nlm.nih.gov. 2017 [cited 21 April 2017]. Available from:

https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~3XwhZE:1

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Information on this page was last updated on 16 Nov 2017

Disclaimer

We’ve made all possible efforts to ensure that the information provided here is accurate, up-to-date and complete, however, it should not be treated as a substitute for professional medical advice, diagnosis or treatment. Practo only provides reference source for common information on medicines and does not guarantee its accuracy or exhaustiveness. The absence of a warning for any drug or combination thereof, should not be assumed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Practo does not assume any responsibility for any aspect of healthcare administered with the aid of information provided above. If you have any doubts about your medication then we strongly recommend that you consult with your doctor, nurse or healthcare provider. See detailed T&C here.