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Before taking phenytoin
Before taking phenytoin make sure your doctor or pharmacist knows:
- If you are pregnant, trying for a baby or breast-feeding.
- If you suffer from liver problems.
- If you suffer from porphyria (a blood disorder).
- If you have ever had an allergic reaction to this or any other medicine.
- If you are taking any other medicines, including those available to buy without a prescription, herbal and complementary medicines.
How to take phenytoin
- Take phenytoin exactly as you have been told by your doctor.
- Before beginning treatment, read the manufacturer's printed information leaflet.
- It is best to take phenytoin with or after food.
- Swallow the capsules whole with a drink of water.
- Phenytoin chewable tablets may be chewed before swallowing or they can be swallowed whole with a drink of water.
- If you are taking phenytoin oral suspension, make sure you shake the bottle before you measure out your dose.
- Try to take phenytoin at the same times each day to avoid missing any doses.
- If you do forget to take a dose, take one as soon as you remember unless it is nearly time for your next dose. If so, then skip the missed dose. Do not take two doses at the same time to make up.
Getting the most from your treatment
- Keep your regular doctor's appointments so that your progress can be monitored.
- People with epilepsy must stop driving. Your doctor will advise you about when it may be possible for you to resume driving again. This will usually be after a year free of seizures.
- Do not stop taking phenytoin without speaking to your doctor first. Stopping suddenly may cause fits. Your doctor will need to reduce the dose you are taking gradually.
- The amount of phenytoin contained in the liquid or chewable tablet forms of phenytoin may be different from that in the capsule or tablet forms. For this reason it is important that you do not change the form of phenytoin that you are taking without discussing it first with your doctor.
- It is best not to drink alcohol with phenytoin. This is because alcohol can alter the amount of phenytoin in your body.
- If you are having any treatment like an operation or dental treatment, tell the person carrying out the treatment that you are taking phenytoin.
- If you buy any medicines (including herbal remedies), check with a pharmacist that they are safe to take with phenytoin.
Can phenytoin cause problems
Along with their useful effects all medicines can cause unwanted side effects, which usually improve as your body adjusts to the new medicine. Speak with your doctor or pharmacist if any of the following side effects continue or become troublesome.
| Common side-effects - these affect less than 1 in 10 people who take this medicine | What can I do if I experience this |
| Feeling or being sick | Eat little and often. Stick to simple foods |
| Constipation | Eat a well balanced diet containing plenty of fibre. Drink 6-8 glasses of water each day |
| Dizziness, drowsiness | Getting up slowly should help. Make sure your reactions are normal before driving, operating machinery or doing any other jobs which could be dangerous if you were not fully alert |
| Headache | Ask your pharmacist to recommend a suitable pain-killer |
| Rash | Let your doctor know about this, even if it is mild |
| Difficulty sleeping, nervousness, unsteadiness, shakiness, numbness or tingling sensations, weight loss, sore or swollen gums, acne, increased hair growth, difficulty controlling movements | If any of these are particularly troublesome, let your doctor know |
Important: While you are taking phenytoin, there is a small risk that you may develop mood changes, distressing thoughts and feelings about suicide. If this happens, tell your doctor straight away.
If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.
How to store phenytoin
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
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References
- Manufacturer's PIL, Epanutin® Capsules, Pfizer Limited, electronic Medicines Compendium. Dated January 2008, accessed November 2008.
- Manufacturer's PIL, Epanutin® Oral Suspension, Pfizer Limited, electronic Medicines Compendium. Dated September 2007, accessed November 2008.
- Manufacturer's PIL, Epanutin® Infatabs, Pfizer Limited, electronic Medicines Compendium. Dated July 2005, accessed November 2008.
- British National Formulary; 56th Edition (September 2008) British Medical Association and Royal Pharmaceutical Society of Great Britain, London (link to current BNF).