Dr. C P Ravi Kumar
Dr. C. P. Ravi Kumar Lead & Senior Consultant – Paediatric Neurology, The Krishna Institute of Medical Sciences (KIMS), Mahadevapura, Bangalore
What is Fosphenytoin ?
It is an anti seizure medicines, used as Intravenous preparation (INJECTION) in emergencies. It is a water-soluble prodrug of phenytoin; After administration, body enzymes convert Fosphenytoin to phenytoin as the active moiety. It is available as only injection preparation, hence its use is restricted to healthcare settings (Hospital)
Advantages of Fosphenytoin over phenytoin:
Fosphenytoin is water soluble, can be administered faster, less irritating on veins and also has less side effects compared to phenytoin.
By what mechanism does Fosphenytoin work?
It is a sodium channel blocker, reduces abnormal signals and stops seizures.
How much time does it take for Fosphenytoin to start acting?
Fosphenytoin typically starts working within 15 to 30 minutes when given through an intravenous (IV) injection. It can also be administered as intramuscular injection. Administration by healthcare professionals only
Could there be negative side effects from this medication?
Every medication can have both benefits and potential risks. While most people do not experience serious side effects, it’s important to be aware of them, and also some side effects may be exaggerated due to underlying reason for seizures / emergency. This medicine is used in emergency and we need to be aware of this medicine is of utmost importance.
Immediate side effects: severe hypotension, cardiac arrhythmias
Common side effects: Tinnitus (ringing in ears), hearing loss, drowsiness, uncontrolled eye movements, Thrombocytopenia, Leukopenia.
Be cautious of severe reactions to Fosphenytoin, such as severe allergic reactions, skin rashes, liver issues, or heart problems. Get medical help right once, If you experience any of these symptoms.
PREGNANCY AND LACTATION:
Fosphenytoin is generally not recommended during pregnancy, however in an emergency it can be used for immediate termination of seizure. If seizure is not controlled, it can have detrimental effect on both mothers and fetus health. Here the benefit outweighs risk.
Lactation: While it is usually considered safe for use during breastfeeding, it is recommended that a doctor monitor both the mother and the infant closely. Generally it is not used long term, hence this question may not actually arise.
MONITORING PARAMETERS:
Regular monitoring of electrocardiogram, blood pressure, and respiratory function.
SUMMARY:
Fosphenytoin is a medication used to treat seizures, including severe ones like status epilepticus. It is usually given through an injection, either into a vein or muscle, and works by being converted into active molecule in the body. It is used only in emergencies.
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REFERENCE:
Author:
- Dr. Likitha B S, Pharm. D, Clinical Pharmacologist, Aster Hospitals, Bengaluru
- Dr Praveen Kumar, B. Pharm, Pharm D(PB), Lead Clinical Pharmacologist, REGIONAL HEAD KIMS Hospitals, Bengaluru
- Dr. C. P. Ravi Kumar Lead & Senior Consultant – Paediatric Neurology KIMS HOSPITALS BENGALURU