1. What’s phenytoin
Phenytoin is a medication used to deal with epilepsy. It may also be used to deal with trigeminal neuralgia, a kind of nerve ache that impacts your face.
Phenytoin is accessible on prescription. It comes as tablets that may be chewed or dissolved in water, capsules and a liquid that you simply swallow.
2. Gwybodaeth allweddol
- It is regular to take phenytoin a few times a day. You possibly can take it with or with out meals.
- The most typical unwanted side effects of phenytoin are complications and feeling dizzy.
- It takes round 4 weeks for phenytoin to work.
- When you’ve got epilepsy, it is best to remain on the identical model of phenytoin, as different manufacturers might not work as effectively for you.
- For those who take it for trigeminal neuralgia, most individuals shouldn’t have to remain on the identical model.
3. Who can and can’t take phenytoin
Phenytoin will be taken by adults and kids of any age. Phenytoin will not be appropriate for some individuals.
To verify phenytoin is protected for you, inform your physician if you happen to:
- have ever had an allergic response to phenytoin or different medicines prior to now
- have liver or kidney issues
- have a blood dysfunction known as porphyria
- can’t have alcohol – phenytoin liquid incorporates a small quantity of alcohol
- have had a rash brought on by phenytoin prior to now
- are pregnant or planning to grow to be pregnant
- have ever had an allergic response to carmoisine (E122) or sundown yellow (E110) – some manufacturers of phenytoin liquid and tablets comprise these
- have an intolerance to or can’t take up some sugars – some manufacturers of phenytoin tablets comprise sugars
4. How and when to take phenytoin
Phenytoin is a prescription medication. It is vital to take it as suggested by your physician.
Dos
The standard dose of phenytoin to deal with epilepsy in:
- adults is between 200mg and 500mg a day, taken as 1 or 2 doses
- youngsters (aged 12 to 17 years) is between 300mg and 400mg, taken as 2 doses
- youngsters (aged as much as 11 years) varies relying on their weight
The standard dose to deal with trigeminal neuralgia in adults is between 300mg and 500mg a day, taken as 1 or 2 doses.
Find out how to take it
It is regular to take phenytoin a few times a day. You possibly can take it with or with out meals.
For those who take it twice a day, attempt to house your doses evenly by means of the day. For instance, very first thing within the morning and within the night.
- Capsules and tablets – swallow complete with a glass of water, milk or juice. Don’t chew them.
- Chewable tablets – will be swallowed complete with a glass of water or chewed.
- Liquid – this comes with a syringe or spoon that will help you measure it. For those who shouldn’t have a syringe or spoon, ask your pharmacist for one. Don’t use a kitchen teaspoon because it won’t provide the correct amount.
Will my dose go up or down?
To stop unwanted side effects, your physician will prescribe a low dose to begin with after which improve it over a number of weeks.
You would possibly have to have blood exams whenever you begin phenytoin or in case your dose is modified. That is to verify your dose is true. When you discover a dose that fits you, it’s going to often keep the identical.
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- When you’ve got epilepsy, it is probably that after your situation is below management you may nonetheless have to take phenytoin for a few years.
- When you’ve got trigeminal neuralgia, phenytoin shall be continued for so long as crucial, generally a few years, except your ache will get higher or disappears altogether.
- Don’t cease taking phenytoin with out speaking to your physician first.
What if I neglect to take it?
For those who take phenytoin and miss a dose:
- as soon as a day – take the missed dose as quickly as you bear in mind. If it is lower than 12 hours earlier than the subsequent dose is due, it is higher to go away out the missed dose and take your subsequent dose as regular.
- twice a day – take the missed dose as quickly as you bear in mind. If it is lower than 8 hours earlier than the subsequent dose is due, it is higher to go away out the missed dose and take your subsequent dose as regular.
By no means take 2 doses on the identical time. By no means take an additional dose to make up for a forgotten one.
When you’ve got epilepsy, it is vital to take this medication frequently. Lacking doses might set off a match (seizure). For those who neglect doses usually, it could assist to set an alarm to remind you.
You may additionally ask your pharmacist for recommendation on different methods that will help you bear in mind to take your medication.
What if I take an excessive amount of?
Taking an excessive amount of phenytoin may cause disagreeable unwanted side effects.
Pressing recommendation: Name 111 for recommendation now if:
- you’re taking an excessive amount of phenytoin – even if you happen to shouldn’t have any unwanted side effects
If you could go to A&E, don’t drive your self. Get somebody to drive you or name for an ambulance.
Take the phenytoin packet or the leaflet inside it, plus any remaining medication, with you.
5. Negative effects
Like all medicines, phenytoin may cause unwanted side effects, though not everybody will get them.
Pores and skin rashes
It’s normal to get a pores and skin rash with phenytoin. Most pores and skin rashes aren’t critical.
However if you happen to develop a pores and skin rash or redness, inform a health care provider right away, as this may develop right into a life-threatening pores and skin situation known as Stevens-Johnson syndrome.
Stevens-Johnson syndrome is a uncommon facet impact of phenytoin.
It causes flu-like signs, adopted by a pink or purple rash that spreads and kinds blisters. The affected pores and skin finally dies and peels off.
It is extra more likely to occur within the first 8 weeks of beginning phenytoin, or when the dose is elevated too shortly.
It will probably additionally occur if phenytoin is stopped immediately for a couple of days after which restarted on the identical dose as earlier than, with out lowering the dose after which rising it slowly once more.
Stevens-Johnson syndrome is extra widespread in:
- youngsters
- individuals who have developed a rash earlier than with a unique epilepsy medication
- people who find themselves allergic to an antibiotic known as trimethoprim
- individuals additionally taking a medication known as sodium valproate
To assist stop the possibility of you getting a rash that might be confused with Stevens-Johnson syndrome, it is best to not begin any new medicines, meals or merchandise through the first 3 months of remedy with phenytoin.
It is also finest to not begin phenytoin inside 2 weeks of a viral an infection, vaccination or rash brought on by one thing else.
Widespread unwanted side effects
These widespread unwanted side effects might occur in additional than 1 in 100 individuals. They’re often gentle and go away by themselves.
Hold taking the medication and speak to your physician or pharmacist if these unwanted side effects hassle you or don’t go away:
- complications
- feeling drowsy, sleepy or dizzy
- feeling nervous, unsteady or shaky
- feeling or being sick (nausea or vomiting)
- constipation
- sore or swollen gums
- gentle pores and skin rash
Some unwanted side effects of phenytoin put on off as soon as your physique will get used to the medication, however it could actually take a number of weeks or months.
Sgîl-effeithiau critigol diangen
Only a few individuals taking phenytoin have critical issues.
Inform your physician right away when you’ve got a critical facet impact, together with:
- ideas of harming or killing your self – a small variety of individuals taking phenytoin have had suicidal ideas, which may occur after a couple of weeks of remedy
- surprising bruising or bleeding, a excessive temperature or sore throat – these might be warning indicators of a blood dysfunction
- a excessive temperature with swollen glands and a pores and skin rash, generally with yellowing of your pores and skin or the whites of your eyes, significantly within the first 2 months of remedy – these could also be indicators of a hypersensitivity response, which is extra more likely to occur if you happen to’re black African-Caribbean or have a weakened immune system
- a pores and skin rash – this is perhaps an indication of Stevens-Johnson syndrome
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In uncommon circumstances, it is potential to have a critical allergic response (anaphylaxis) to phenytoin.
Speedy motion required:
- you get a pores and skin rash that will embrace itchy, pink, swollen, blistered or peeling pores and skin
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- rydych chi'n mynd yn dynn yn y frest neu'r gwddf
- you might have hassle respiration or speaking
- eich ceg, wyneb, gwefusau, tafod neu wddf yn dechrau chwyddo
You may be having a critical allergic response and might have speedy remedy in hospital.
These aren’t all of the unwanted side effects of phenytoin.
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What to do What’s:
- complications – ensure you relaxation and drink loads of fluids. Don’t drink an excessive amount of alcohol. If it is an issue, ask your pharmacist to suggest a painkiller. Speak to your physician in case your complications last more than per week or are extreme.
- feeling drowsy, sleepy or dizzy – as your physique will get used to phenytoin, these unwanted side effects ought to put on off. Don’t drive, trip a motorbike or function equipment till you are feeling extra alert. If they don’t go inside per week or two, your physician might scale back your dose or improve it extra slowly. If that doesn’t work, chances are you’ll want to change to a unique medication.
- feeling nervous, unsteady or shaky – speak to your physician if this bothers you. These signs could be a signal that the dose is simply too excessive for you.
- feeling or being sick – persist with easy meals and don’t eat wealthy or spicy meals. It’d assist to take your phenytoin after a meal or snack. For those who’re being sick, attempt taking small, frequent sips of water to keep away from dehydration. Indicators of dehydration embrace peeing lower than regular or having darkish, strong-smelling pee. Communicate to a health care provider in case your signs worsen or final greater than week.
- constipation – eat extra high-fibre meals, corresponding to recent fruit and greens, and cereals. Attempt to drink a number of glasses of water or one other non-alcoholic liquid every day. For those who can, attempt to train extra frequently – for instance, by occurring a each day stroll or run.
- sore or swollen gums – brush your enamel and gums twice a day to assist cease this taking place, and go to your dentist frequently
- gentle pores and skin rash – it could assist to take an antihistamine, which you should buy from a pharmacy. Examine with the pharmacist to see what kind is appropriate for you. Use lukewarm water fairly than sizzling within the bathe. Contact your physician if it spreads, will get very itchy or lasts greater than a few days.
7. Bod yn feichiog a bwydo ar y fron
Phenytoin and being pregnant
- Phenytoin has been linked to an elevated threat of issues in your unborn child.
- You may often solely be suggested to take it in case your physician thinks the advantages of the medication outweigh the dangers.
- It is vital that you simply and your child keep effectively throughout being pregnant.
- For those who take phenytoin and grow to be pregnant, inform your physician or nurse right away.
- When you’ve got epilepsy, it is essential that it is handled throughout being pregnant as seizures can hurt you and your unborn child.
- Don’t cease taking it with out speaking to your physician first.
- For those who’re pregnant or making an attempt to get pregnant and taking phenytoin, you are really helpful to take the next dose of folic acid, a vitamin that helps your child develop usually.
- Your physician would possibly prescribe a excessive dose of 5mg a day so that you can take whenever you’re making an attempt to get pregnant and through the first 12 weeks of being pregnant.
Phenytoin and breastfeeding
- In case your physician or well being customer says your child is wholesome, phenytoin will be taken when you’re breastfeeding.
- Phenytoin passes into breast milk in small quantities. There have been some experiences of unwanted side effects in breastfed infants, however typically infants don’t get any unwanted side effects.
- It is vital to maintain taking phenytoin to maintain you effectively. Don’t cease taking it with out speaking to your physician.
- Breastfeeding may even profit each you and your child.
- For those who discover that your child’s not feeding in addition to regular, appears unusually sleepy, or you might have another issues What’s them, speak to your pharmacist, well being customer or physician as quickly as potential.
Non-urgent recommendation: Inform your physician if you happen to’re:
- making an attempt to get pregnant
- feichiog
- bwydo ar y fron
8. Rhybuddion gyda gwahanol feddyginiaethau
There are many medicines that may have an effect on phenytoin and improve the possibilities of you having unwanted side effects. If you could take these medicines, your physician might change your dose of phenytoin.
Inform your physician if you happen to’re taking:
- different medicines used to deal with epilepsy, corresponding to carbamazepine, clonazepam, lamotrigine, phenobarbital, sodium valproate, topiramate, oxcarbazepine, ethosuximide and vigabatrin
- medicines used to deal with HIV
- hormonal contraceptives or hormone alternative remedy (HRT)
- medicines used for coronary heart and circulation issues like digoxin, amiodarone, furosemide, warfarin, diltiazem, nifedipine, apixaban and ticagrelor
- medicines used to deal with fungal infections like fluconazole, itraconazole and miconazole
- medicines used for tuberculosis and different infections like isoniazid, rifampicin, sulfamethoxazole-trimethoprim, doxycycline and ciprofloxacin
- medicines used for abdomen issues like omeprazole, sucralfate, ranitidine and a few antacids
- theophylline, a medication to assist with respiration issues
- medicines used for sleeplessness and psychological well being issues like chlordiazepoxide, clozapine, clobazam, diazepam, disufiram, fluoxetine, quetiapine, trazodone and amitriptyline
- medicines used for transplants corresponding to ciclosporin and tacrolimus
- medicines used for most cancers
- bupropion, a medication that will help you quit smoking
This isn’t a full listing of medicines that may have an effect on phenytoin.
Mixing phenytoin with natural cures and dietary supplements
There could also be an issue taking some natural cures and dietary supplements alongside phenytoin. Don’t take St John’s wort with phenytoin, because it decreases the quantity of phenytoin in your blood.
For those who already take it, speak to your physician earlier than stopping St John’s wort as they could want to extend your phenytoin dose.
Necessary:
Inform your physician or pharmacist if you happen to’re taking another medicines, together with natural medicines, nutritional vitamins or dietary supplements.
9. Widespread questions What’s phenytoin
Angenrheidiol
Don’t cease taking phenytoin with out speaking to your physician first.
Associated circumstances
- Epilepsy
- Epilepsy and being pregnant
- Trigeminal neuralgia
Helpful assets
- HealthUnlocked: phenytoin discussion board
- UK Epilepsy & Being pregnant Register
