Information about Fosphenytoin

Fosphenytoin Uses

Fosphenytoin is used in the treatment of epilepsy/seizures.

How Fosphenytoin works

Fosphenytoin is an antiepileptic medication. It controls seizures or fits by decreasing the abnormal and excessive activity of the nerve cells in the brain.

Common side effects of Fosphenytoin

Vomiting, Sleepiness, Dizziness, Itching, Nystagmus (involuntary eye movement), Headache, Nausea, Dryness in mouth, Blurred vision, Paresthesia (tingling or pricking sensation), Vertigo, Tremors, Euphoria (feeling of intense excitement and happiness), Taste change, Ringing in ear, Abnormality of voluntary movements, Coordination disorder, Difficulty in speaking, Stupor, Visual impairment, Lazy eye, Deafness, Hypotension (low blood pressure), Ecchymosis (discoloration of the skin resulting from bleeding underneath), Injection site reactions (pain, swelling, redness), Weakness, Chills
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Last updated
29 Sep 2022 | 02:38 PM (UTC)

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Available Medicine for Fosphenytoin

FosolinZydus Cadila
102 to ₹3933 variant(s)
FosphenIntas Pharmaceuticals Ltd
51 to ₹2262 variant(s)
NeofostNeon Laboratories Ltd
49 to ₹632 variant(s)
RapitoinEmcure Pharmaceuticals Ltd
331 variant(s)
MilorgenRSM Kilitch Pharma Pvt Ltd
36 to ₹1672 variant(s)
FosentinSun Pharmaceutical Industries Ltd
32 to ₹1512 variant(s)

Expert advice for Fosphenytoin

  • It is given as an injection either into a vein (intravenously) or into a muscle (intramuscularly).
  • Take your medication regularly as directed by your doctor as missing doses can trigger seizures.
  • Do not change the brand of your medicine and make sure that you have sufficient amount of medicine present with you.
  • Some healthy tips to prevent seizures:
    • Practice yoga every day.
    • Get enough sleep at nighttime.
    • Limit the use of screen time such as mobile/laptop.
    • Take your medication on time.
  • It may cause dizziness and sleepiness. Do not drive or do anything that requires mental focus until you know how it affects you.
  • It may increase blood sugar levels.Inform your doctor if you are taking any medicines to treat diabetes.
  • Inform your doctor if you develop any unusual changes in mood or behavior, new or worsening depression, or suicidal thoughts or behavior.

Frequently asked questions for Fosphenytoin


Q. Why is Fosphenytoin better than phenytoin?

Fosphenytoin does not have side effects which are commonly associated with the use of phenytoin such as injection site irritation and sudden changes in the heart rate (arrhythmia), hence Fosphenytoin is better than phenytoin.

Q. What happens if I stop taking Fosphenytoin?

Suddenly stopping Fosphenytoin may cause non-stop seizures (called status epilepticus), which can endanger life. Hence, do not stop taking the medicine without consulting your doctor. If required, your doctor may slowly reduce the dose before stopping it completely.

Q. What are the symptoms that occur if I take more than the recommended dose of Fosphenytoin? Can I die from Fosphenytoin overdose?

Overdose of Fosphenytoin may cause jerky movements of the eyes (nystagmus), unclear speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, lightheadedness, fainting, blurred vision, slow and shallow breathing and even coma. Fosphenytoin overdose can cause very low blood pressure and respiratory problems. As a result of this, the patient can even die.

Q. What are the effects of Fosphenytoin on children?

The most common side effects related to Fosphenytoin in children are jerky movements of the eyes (nystagmus) and overgrowth of the gums. In some children, Fosphenytoin causes problems with thinking or behavior, mood change, slow or clumsy movements, or a loss of energy. Other side effects from high doses include unsteadiness in the feet and hands, sleepiness, and vomiting. These may be avoidable if the dose is increased slowly. These side effects quickly disappear when the dose is reduced.

Q. For how long does Fosphenytoin stay in your system?

On an average, Fosphenytoin may stay in your system for 5-6 days. This duration varies from person to person. In some cases, it may stay for about 9-10 days.

Q. Does Fosphenytoin affect birth control?

Fosphenytoin does affect birth control. Fosphenytoin can decrease the effect of oral contraceptives (birth control pills) which can make the contraceptive (birth control) effect unreliable. Please talk to your doctor if you are asked to take the two medicines together as you may need to use extra protection for birth control.

Q. Does Fosphenytoin make you sleepy?

Fosphenytoin can make you feel sleepy (sedation, somnolence, and drowsiness). Please consult your doctor if you feel very sleepy after taking Fosphenytoin, especially during the first few weeks of treatment or following a dose increase. Talk to your doctor as you may be advised not to drive or use machines until it is established that your ability to perform such activities is not affected.

Q. Does Fosphenytoin cause weight gain?

No, Fosphenytoin has not been reported to cause weight gain. However, weight loss can occur with longer term use of a higher dose of Fosphenytoin. Please consult your doctor if you experience weight gain after taking Fosphenytoin.


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