Phenytoin is used to treat and prevent seizures that may start during or after brain or nervous system surgery, as well as to control some types of seizures. The drug phenytoin belongs to the group of drugs known as anticonvulsants. It functions by reducing the brain’s aberrant electrical activity.

The three different oral dosage forms of phenytoin are an extended-release (long-acting) capsule, a chewable tablet, and a solution (liquid). The suspension and chewable pill are often taken twice or three times daily. Typically, one to four times a day are used to take the extended-release capsules. Phenytoin should be taken every day at about the same time(s). Ask your doctor or chemist to explain any instructions on your prescription label that you are unsure about following. Follow the prescription for phenytoin strictly. Never take it in larger or less amounts or more frequently than directed by your doctor.

Starting with a modest dose, your doctor will gradually raise it no more frequently than once every 7-10 days as directed.

Because different phenytoin products are absorbed by the body in various ways, they cannot be interchanged. Your doctor might need to change your dose if you need to transition from one phenytoin product to another. Verify that you have received the phenytoin product that was prescribed for you each time you receive a medication. If you are unsure if you were given the correct medication, speak with your chemist.

Before each usage, give the beverage a good shake to evenly distribute the medication. Make sure you are receiving the proper dosage of medication by using an accurate measuring device. If you have any concerns about how to estimate your dose, consult your doctor or chemist.

Do not break, chew, or crush the extended-release capsules; instead, swallow them whole. Take care not to consume coloured capsules.

The chewable tablets can be properly chewed before being swallowed, or they can be taken whole without being chewed.

Ask your doctor when you should take phenytoin if you receive formula or supplements through a feeding tube. You’ll need to give yourself some time in between eating and taking phenytoin.

Your problem won’t be cured with phenytoin, but it might help you manage it. Taking phenytoin is still necessary even if you feel OK. Even if you encounter side effects such odd changes in behaviour or mood, you should not discontinue taking phenytoin without first consulting your doctor. Your seizures can get worse if you stop taking phenytoin all of a sudden. Your dose will likely be gradually reduced by your doctor.

Moreover, phenytoin is utilised to manage irregular heartbeat. The dangers of using this drug for your illness should be discussed with your doctor.

Ask your doctor or chemist for more details if you believe this drug should be used for something else.

Before taking phenytoin,

• If you have an allergy to phenytoin, other hydantoin drugs like ethotoin (Peganone) or fosphenytoin (Cerebyx), any other medications, or any of the chemicals in phenytoin, let your doctor and pharmacist know right away. Get a list of the ingredients from your chemist.
• Informing your physician that you are taking Delavirdine (Rescriptor). If you are taking this drug, your doctor generally won’t advise you to take phenytoin.
• Inform your doctor and chemist about all prescription and over-the-counter drugs, vitamins, dietary supplements, and herbal products that you are now taking or intend to use. Incorporate any of the following: Albendazole (Albenza), amiodarone (Nexterone, Pacerone), warfarin (Coumadin, Jantoven), and other anticoagulants (also known as “blood thinners”); antifungal drugs like miconazole (Oravig), posaconazole (Noxafil), ketoconazole (Nizoral), itraconazole (Onmel, Sporanox, Tolsura), and fluconazole (Diflucan); a number of antiviral medications, including efavirenz (Sustiva, in Atripla), indinavir (Crixivan), lopinavir, nelfinavir, ritonavir, and saquinavir (Invirase); bleomycin; capecitabine (Xeloda); carboplatin; and chloramphenicol; cisplatin; clozapine (Fazaclo, Versacloz); cyclosporine (Gengraf, Neoral, Sandimmune); chlordiazepoxide (Librium, in Librax); cholesterol medicines such as atorvastatin (Lipitor, in Caduet), fluvastatin (Lescol), and simvastatin (Zocor, in Vytorin); digoxin (Lanoxin), doxorubicin (Doxil), doxycycline (Acticlate, Doryx, Monodox, Oracea, and Vibramycin), diazepam (Valium), diazoxide (Proglycem), disopyramide (Norpace), disulfiram (Antabuse), fluorouracil; fluvoxamine (Luvox), fluoxetine (Prozac, Sarafem, in Symbyax, among others); folic acid; fosamprenavir (Lexiva); and furosemide (Lasix); hormonal contraceptives (birth control pills, patches, rings, or injections); hormone replacement treatment (HRT); irinotecan (Camptosar); isoniazid (Laniazid, in Rifamate, in Rifater); H2 antagonists like cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac); medications for nausea and mental illness; additional seizure medications like oxcarbazepine (Trilepta, Oxtellar XR), ethosuximide (Zarontin), felbamate (Felbatol), lamotrigine (Lamictal), methsuximide (Celontin), carbamazepine (Carbatrol, Equetro, Tegretol, and others); phenobarbital; topiramate (Topamax); methylphenidate (Daytrana, Concerta, Metadate, Ritalin), methadone (Dolophine, Methadose), methotrexate (Otrexup, Rasuvo, Trexall, Xatmep), mexiletine; omeprazole (Prilosec), dexamethasone, methylprednisolone (Medrol), prednisolone, and prednisone (Rayos); nifedipine (Adalat, Procardia), nimodipine (Nymalize), and nisoldipine (Sular); rifampin (Rifadin, Rimactane, in Rifamate, in Rifater); paclitaxel (Abraxane, Taxol); paroxetine (Paxil, Pexeva); praziquantel (Biltricide); quetiapine (Seroquel); quinidine (in Nuedexta); reserpine; aspirin, choline magnesium trisalicylate, choline salicylate, diflunisal, magnesium salicylate (Doan’s, others), and salsalate are examples of salicylate analgesics; teniposide, theophylline (Elixophyllin, Theo-24, Theochron), sertraline (Zoloft), sucralfate (Carafate), sulfa antibiotics, tolbutamide, and trazodone; vitamin D, vigabatrin (Sabril), and verapamil (Calan, Verelan in Tarka). Your physician might need to adjust the dosage of your medications or keep a closer eye on you for side effects.
• If you take antacids that contain calcium, magnesium, or aluminium, let your doctor know (Maalox, Mylanta, Tums, others). Your doctor might advise you to wait a while before taking phenytoin after having an antacid.
• Please let your doctor know if you are taking any herbal supplements, particularly St. John’s wort.
• If you ever experienced hepatic issues while taking phenytoin, let your doctor know. You won’t want to take phenytoin again, your doctor will likely advise.
• If you consume large amounts of alcohol now or have ever done so, let your doctor know. Inform your doctor if laboratory tests revealed an inherited risk factor that increases your chance of developing a severe skin reaction to phenytoin. Additionally, let your doctor know if you have or have ever had diabetes, osteopenia, osteomalacia, or osteoporosis (conditions that cause the bones to be soft or brittle and may break easily), low albumin levels in your blood, or heart, kidney, or liver disease. Porphyria is a condition in which certain natural substances build up in the body and may cause stomach pain, changes in thinking or behaviour, or other symptoms.
• Inform your physician if you are nursing a baby, intend to become pregnant, or are already expectant. While taking phenytoin, you shouldn’t get conceived. Consult your doctor about reliable birth control options you can use while undergoing therapy. Call your doctor if you get pregnant while taking phenytoin. The foetus could suffer from phenytoin.
• Inform your doctor or dentist that you are taking phenytoin if you are having surgery, including dental surgery.
• You should know that this drug may cause dizziness, drowsiness, and problems with coordination. Before you know how this medication affects you, do not operate machinery or drive a car.
• Speak to your doctor about the safe use of alcohol while you are taking this medication.
• You should be aware that while taking phenytoin, your mental health may change in unexpected ways and that you could develop suicidal thoughts, including plans or actual attempts to harm or kill yourself. In clinical studies, a small percentage of patients receiving anticonvulsants like phenytoin to treat a variety of conditions about 1 in 500 adults and children aged 5 and older became suicidal while receiving treatment. Some of these individuals began exhibiting suicidal thoughts and actions as soon as one week after beginning the medication. If you take an anticonvulsant drug like phenytoin, there is a chance that your mental state will change, but there is also a chance that your disease won’t be treated and that your mental state won’t change. Whether the risks of using an anticonvulsant drug outweigh the risks of not using it will be decided by you and your doctor. Any of the following symptoms should prompt you, your family, or your carer to contact your doctor right away: panic episodes, agitation or restlessness, as well as newly-appearing or worsening irritability, anxiety, or melancholy; acting on risky urges, having trouble falling or staying asleep, acting out in an angry or violent manner, or experiencing mania (a maniacal, abnormally excited state of mind); expressing or having thoughts of wishing to harm or end one’s life; abandoning relatives and friends; giving away prized possessions, obsessing over mortality and dying, or any other unusual changes in mood or behaviour. Make sure your family or carer is aware of any symptoms that could be severe so they can contact the doctor on your behalf if you are unable to call for help.
• During your phenytoin treatment, discuss with your doctor the best method to take care of your teeth, gums, and mouth. It’s crucial that you take good care of your teeth to reduce the possibility of gum damage brought on by phenytoin.

Keep eating normally unless your doctor instructs you otherwise.

If you miss a dosage, take it as soon as you recall. If the next dose is soon due, skip the missed one and carry on with your regular dosing plan. To make up for a missing dose, do not take a second one.

Your blood sugar may rise as a result of phenytoin. The signs of high blood sugar and what to do if you encounter them should be discussed with your doctor.

Side effects from phenytoin are possible. If any of these symptoms are severe or do not go away, let your doctor know right once:

• Having trouble falling or staying asleep
• Irregular eye motions
• Inconsistent body movements
• Inability to coordinate
• Confusion
• Muddled statement
• Headache
• Alterations to your palate
• Constipation
• Excessive hair growth
• The deterioration of facial characteristics
• Expansion of the cheeks
• Gum proliferation
• Discomfort or penis curvature

• Enlarged nodes
• Blisters
• Nausea
• Vomiting
• Skin or irises becoming yellow
• Stomach’s top right corner hurts
• Extreme fatigue
• Extraordinary bruising or haemorrhaging
• Small skin patches that are red or purple
• Reduced hunger
• Flu-like signs
• Inflammation of the face, a temperature, a sore tongue, a rash, mouth ulcers, or easy bruising
• Chest pain, fatigue, dizziness, or an irregular heartbeat
• Breathing difficulty
• Hives

Certain adverse effects can be very harmful. Call your physician and stop taking phenytoin if you encounter any of the following symptoms:

• Swelling of the lips, throat, tongue, eyes, or forehead
• Respiration or swallowing challenges

Further negative effects of phenytoin may occur. If you have any strange side effects while taking this medicine, contact your doctor right once.

You or your doctor can submit a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting programme online or by phone if you have a serious side event (1-800-332-1088).

Phenytoin use may raise your risk of developing osteopenia, osteoporosis, or osteomalacia as well as issues with your lymph nodes, such as Hodgkin’s disease (cancer that begins in the lymph system). Discuss the dangers of using this drug to treat your disease with your doctor.

Keep this medication tightly closed in the original container and out of the reach of children. Keep it at ambient temperature and shield it from light, too much heat, and moisture (not in the bathroom). Don’t let the liquid freeze.

Although many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and are simple for young children to open, it is crucial to keep all medications out of sight and out of reach of children. Always lock safety caps and promptly stash medication up and away from young children where it is out of their sight and reach to prevent poisoning. http://www.upandaway.org

Unused prescriptions must be disposed of carefully to prevent pets, kids, and other people from ingesting them. You should not, however, dispose of this medication in the toilet. Instead, utilising a medicine take-back programme is the easiest approach to get rid of your medication. To find out about take-back programmes in your area, speak with your chemist or the garbage/recycling agency in your city. If you do not have access to a take-back programme, see the FDA’s Safe Disposal of Medications website at http://goo.gl/c4Rm4p for additional information.

Call the poison control hotline at 1-800-222-1222 in the event of an overdose. Moreover, information can be found online at https://www.poisonhelp.org/help. Call 911 right once if the person has collapsed, experienced a seizure, is having difficulty breathing, or cannot be roused.

Overdose signs could include the following:

• Irregular eye motions
• Inability to coordinate
• Slurred or sluggish speech
• Fuzzy vision
• Fatigue
• Body part shaking that is uncontrollable
• Nausea
• Vomiting
• Chest pain, fatigue, dizziness, or an irregular heartbeat
• Breathing difficulty

Keep all of your appointments with your physician and the lab. To determine how you are responding to phenytoin, your doctor may prescribe specific lab tests.

Inform the lab staff and your doctor that you are taking phenytoin prior to any laboratory test.

No one else should take your medication. Any queries you may have regarding prescription refills should be directed to your chemist.

You should keep a written record of every medication you take, including any over-the-counter (OTC) items, prescription drugs, and dietary supplements like vitamins and minerals. This list should be brought with you whenever you see a doctor or are admitted to the hospital. You should always have this information with you in case of emergencies.