Fosphenytoin is a water soluble prodrug and a diphosphate ester salt of phenytoin. The plasma esterases will transform the fosphenytoin to phosphate, formaldehyde, and phenytoin as the active component after the administration process. The active component is a major factor for the neuronal membranes to stabilize, it also increases the efflux or decreases the influx of sodium ions across cell membranes during generation of nerve impulses in order to reduce the seizure activity.


Use this medication precisely as recommended by your physician. Follow the prescription of your doctor carefully. 


The medication dose your physician has given is based on your condition, other medications or food supplements you may take, and your reaction to treatment. To diminish your risks for adverse effects, don’t increase your dosage, take it regularly, or take it as instructed by your physician. Adverse events may still happen even at usual prescription dosages. 


If your physician requests you to use this drug consistently, use it regularly to get the most benefits from it. To make you remember it better, take it at a fixed time every day. 


Your doctor may need to modify your dosages to ease your symptoms or if you develop adverse reactions. 


If you have any inquiries with regards to information, ask your physician or pharmacist. 

Fosphenytoin is used in the following conditions:

  • Tonic-clonic status epilepticus
  • Seizures (except status epilepticus)


This medicine may be recommended for different uses. Approach your physician or pharmacist for more information.  

Do not use Fosphenytoin in people with the following conditions:

  • Sinus bradycardia
  • SA block, 2nd- or 3rd-degree AV block
  • Stokes-Adams syndrome
  • Concomitant use w/ delavirdine

Fosphenytoin may have the following side effects:

  • Burning
  • Itching
  • Paraesthesia, particularly in the groin area
  • Oedema
  • Discoloration
  • Pain distal at the injection site (purple glove syndrome)
  • Lymphadenopathy (localized or generalised)
  • Confusional states 
  • Severe cardiovascular reactions associated with rapid infusion
  • Suicidal ideation and behaviour
  • Serious skin reactions
  • Anticonvulsant hypersensitivity syndrome (AHS) 
  • Drug reaction w/ eosinophilia and systemic symptoms (DRESS)
  • Acute hepatotoxicity
  • Haematopoietic complications 


Keep in mind that your physician has recommended this drug since he or she has known that the advantage to you is more noteworthy than the risk of adverse reactions. Many individuals utilizing this medicine don’t have serious side effects.  


A serious allergy to this medication is uncommon. In any case, seek emergency medical help if you see any manifestations of a serious allergic response, including a rash, tingling or swelling particularly of the face or tongue or throat, dizziness or difficulty in breathing. 


This is not a complete list of side effects. If you see other effects not recorded above, contact your physician or pharmacist.

Take extra caution in patients with the following medical conditions:


  • Patient w/ phosphate restriction 
  • Hypoalbuminemia
  • Hypotension 
  • Severe myocardial insufficiency
  • Diabetes mellitus
  • Porphyria
  • Absence seizures and seizures associated w/ hypoglycaemia or other metabolic causes
  • Avoid abrupt withdrawal
  • Renal and hepatic impairment 
  • Elderly
  • Pregnancy and lactation


Prior to taking this medicine, tell your physician or pharmacist if you are allergic to it, or if you have some other hypersensitivities. This drug may contain inert ingredients which can cause unfavorable side effects or different issues. Talk with your pharmacist for more information.



Fosphenytoin may interact with the following medicines:

  • Amiodarone 
  • Antiepileptics
  • Azoles
  • Capecitabine
  • Chloramphenicol
  • Chordiazepoxide
  • Disulfiram
  • Oestrogens
  • Fluorouracil
  • Fluoxetine
  • Fluvastatin
  • Fluvoxamine 
  • H2-antagonists 
  • Halothane
  • Isoniazid
  • Methylphenidate
  • Omeprazole
  • Phenothiazines
  • Salicylates
  • Sertraline
  • Succinimides
  • Sulfonamides
  • Ticlopidine
  • Tolbutamide
  • Trazodone
  • Anticancer drugs
  • Carbamazepine
  • Diazepam
  • Diazoxide
  • Folic acid
  • Fosamprenavir
  • Nelfinavir
  • Reserpine
  • Rifampicin
  • Ritonavir
  • Theophylline
  • Vigabatrin
  • Phenobarbital
  • Valproic acid
  • Na valproate
  • Corticosteroids
  • Doxycycline
  • Furosemide
  • Irinotecan
  • Oral contraceptives
  • Paclitaxel 
  • Paroxetine
  • Quinidine
  • Rifampicin
  • Teniposide
  • Theophylline 
  • Vitamin D
  • Warfarin
  • Albendazole
  • HIV antivirals
  • Atorvastatin
  • Chlorpropamide
  • Clozapine
  • Ciclosporin
  • Digoxin
  • Methadone 
  • Mexiletine
  • Nifedipine
  • Nimodipine
  • Nisoldipine
  • Praziquantel
  • Simvastatin
  • Verapamil
  • Amprenavir
  • Ritonavir
  • Nondepolarizing neuromuscular blocking agents
  • Non-nucleoside reverse transcriptase inhibitors


Inform your physician about the drugs you take including over-the-counter medications, prescribed drugs, supplements and vitamins. 


This is not a complete list of drug interactions. Approach your physician or pharmacist for more details. 


The effects of certain medications can change if you consume different medications or herbal products simultaneously. This can build your risk for side effects or may cause your drugs not to work effectively. These interactions are conceivable, yet don’t generally happen. Your physician or pharmacist can prevent or oversee interactions by changing how you utilize your prescriptions or by close checking. 


While utilizing this drug, don’t start, stop, or change the dose of other medicines you are using without your physician’s advice. 

Symptoms of overdose may include the following:

  • Nystagmus
  • Ataxia 
  • Dysarthria
  • Nausea
  • Vomiting 
  • Lethargy
  • Tachycardia
  • Bradycardia
  • Asystole 
  • Cardiac arrest
  • Hypotension
  • Syncope
  • Hypocalcaemia
  • Metabolic acidosis 
  • Respiratory or circulatory depression


Seek medical help immediately. 


Available Brands: 

  • Cerebyx

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