Urgent advice: Call your doctor or go to A&E straight away if you take too much Epinat and:
- get fast, uncontrollable eye movements
- feel clumsy and lose your balance
- get slurred speech
- have problems breathing
- pass out
If you need to go to A&E, do not drive yourself. Get someone to drive you or call for an ambulance.
Take the Epinat packet or the leaflet inside it, plus any remaining medicine, with you.
Like all medicines, Epinat can cause side effects, although not everyone gets them.
Epinat, formerly known as diphenylhydantoin, is perhaps the most commonly used major anticonvulsant agent, and is a rare but well known cause of acute idiosyncratic drug induced liver disease that can be severe and even fatal.
What Other Drugs Interact with Epinat?
If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.
Epinat has severe interactions with at least 28 different drugs.
Epinat has serious interactions with at least 83 different drugs.
Epinat has moderate interactions with at least 286 different drugs.
Epinat has mild interactions with at least 121 different drugs.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.
What is Epinat Toxicity?
Epinat’s therapeutic level is identified to be between 10-20mcg/mL. The signs and symptoms associated with Epinat toxicity will start to manifest when the serum level of this drug reaches 30 mcg/mL. There are certain factors which may put an individual at a higher risk for the toxicity of Epinat.
The degree of protein binding in the body plays a major role in the metabolism of this medication. Those who have decreased protein binding, such as neonates and elderly patients, have a higher risk than the general population. The metabolism of the drug is decreased and the drug may accumulate in the body .
Decreased bone mineral density reported with chronic use.
See "What Are Side Effects Associated with Using Epinat?”
Commonly reported side effects of Epinat include: congenital anomalies. Other side effects include: hepatic necrosis, ataxia, confusion, constipation, depression, dizziness, drowsiness, fatigue, hypertrichosis, mental status changes, myasthenia, nervousness, numbness, tremor, tremor of hands, vertigo, excitement, irritability, mood changes, and restlessness. See below for a comprehensive list of adverse effects.
2. Key facts
- It's usual to take Epinat once or twice a day. You can take it with or without food.
- The most common side effects of Epinat are headaches and dizziness.
- It takes around 4 weeks for Epinat to work.
- The most common brand names are Epanutin and Epanutin Infatabs.
Epinat sodium (diphenylhydantoin sodium)
Pharmacologic class: Hydantoin derivative
Therapeutic class: Anticonvulsant
Pregnancy risk category D
What if I forget to take it?
If you take Epinat and miss a dose:
- once a day - take the missed dose as soon as you remember. If it's less than 12 hours before the next dose is due, it's better to leave out the missed dose and take your next dose as normal.
- twice a day - take the missed dose as soon as you remember. If it's less than 8 hours before the next dose is due, it's better to leave out the missed dose and take your next dose as normal.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you have epilepsy, it's important to take this medicine regularly. Missing doses may trigger a fit (seizure).
If you forget doses often, it may help to set an alarm to remind you.
You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
Outcome and Management
Acute Epinat hepatitis with jaundice has a fatality rate of greater than 10%. For this reason, Epinat should be stopped promptly if symptoms of liver disease or jaundice arise early during therapy. Monitoring of ALT levels during introduction of Epinat is recommended by some expert groups, but minor ALT elevations are common and it is unclear at what level of elevation that therapy should be suspended. Chronic injury due to Epinat hepatotoxicity is rare or nonexistent, but cases of prolonged jaundice resembling vanishing bile duct syndrome have been reported. Rechallenge leads to rapid and usually more severe recurrence which can be fatal and should be avoided. Cross sensitivity with other aromatic anticonvulsants (phenobarbital, carbamazepine, lamotrigine and ethosuximide) can occur but is not invariable. Nevertheless, it is prudent to avoid use of these other aromatic anticonvulsants and to switch to agents such as valproate, gabapentin, levetiracetam or a benzodiazepine, which do not appear to induce the same hypersensitivity syndrome. Corticosteroid therapy is often used in patients with severe Epinat hepatotoxicity and anecdotal reports suggest that responses are rapid and beneficial. If used, corticosteroid therapy should be limited in dose and duration.
What should I avoid while taking Dilantin?
Avoid drinking alcohol while you are taking Dilantin. Alcohol use can increase your blood levels of Epinat and may increase side effects. Daily alcohol use can decrease your blood levels of Epinat, which can increase your risk of seizures.
Ask a doctor or pharmacist before using over-the-counter medicines such as cimetidine, omeprazole, St. John's wort, or vitamins and mineral supplements that contain folic acid.
Avoid driving or hazardous activity until you know how Dilantin will affect you. Your reactions could be impaired.
Avoid taking antacids at the same time you take Dilantin. Antacids can make it harder for your body to absorb the medication.