Phenytoin: functions, dosage, side effects, how to use it

What Drug Phenytoin?

What is Phenytoin for?

Phenytoin is a drug with a function to prevent and control seizures (also called anticonvulsants or antiepileptic drugs). It works by reducing the spread of seizure activity in the brain.

OTHER PURPOSES: This section contains uses of this medicine that are not listed on labels that are approved by an expert, but may be prescribed by your healthcare professional. Use this medication for the conditions listed in this section if only it has been prescribed by your healthcare professional.

This medication can also be used to treat certain types of irregular heartbeats.

Phenytoin dosage and phenytoin side effects are detailed below.

How to use Phenytoin?

Read the Medication Guide provided by your pharmacist before you start taking Phenytoin and each time you get a refill. If you have questions, ask your doctor or pharmacist.

Tablets can be chewed thoroughly before being swallowed or can be swallowed thoroughly.

Take this medication usually 2 or 3 times a day, or as directed by your doctor. This product is not recommended to be used once a day. You can take it with food in case of stomach upset. Take this medication with a full glass (8 ounces or 240 milliliters) of water unless your doctor directs you otherwise.

Use this remedy regularly for the most benefit. Take all doses in a timely manner to keep the amount of medicine in your body at a constant level. Remember to use it at the same time every day. Dosage is based on your medical condition and response to therapy.

Products containing calcium (eg antacids, calcium supplements) and tube-food (enteral) nutritional products can decrease the absorption of Phenytoin. Do not use this product at the same time as your Phenytoin dosage. Use a separate liquid nutritional product at least 1 hour before and 1 hour after taking your Phenytoin dose, or as directed by your doctor.

Do not stop taking this medication without consulting your doctor. The seizures can get worse when the use of this drug is suddenly stopped. Your dose may need to be decreased gradually.

Tell your doctor if your condition does not improve or gets worse.

Follow the rules given by your doctor or pharmacist before starting treatment. If you have any questions, consult your doctor or pharmacist.

How do I store Phenytoin?

This medication is best stored at room temperature, away from direct light and damp places. Don't keep it in the bathroom. Don't freeze it. Other brands of this drug may have different storage rules. Observe the storage instructions on the product package or ask your pharmacist. Keep all medicines away from children and pets.

Do not flush medicines down the toilet or down the drain unless instructed to do so. Discard this product when it has expired or when it is no longer needed. Consult your pharmacist or local waste disposal company about how to safely dispose of your product.

Phenytoin dosage

The information provided is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist before starting treatment.

What is the Phenytoin dosage for adults?

Usual Adult Dose for Seizures

Oral load dose (except suspension): Only when used for inpatients.

1 g orally divided in 3 doses (400 mg, 300 mg, 300 mg) given at 2 hour intervals. Then the normal maintenance dose is started 24 hours after the loading dose.

Initial dose: 100 mg orally 3 times a day.

Maintenance dose: 100 mg orally 3 to 4 times a day. If seizure control can be done in three divided doses of 100 mg capsules daily, a once-daily dose of 300 mg large-sized Phenytoin sodium can be used. Alternatively, the dose may need to be increased to 200 mg orally 3 times a day, if needed.

Suspension: Patients who have not received previous treatment may be started on 125 mg (one teaspoon) of the suspension three times daily, and this dose is then adjusted to meet individual needs. An increase of five teaspoons daily can be made, if necessary.

IV: Do not exceed the infusion rate of 50 mg / minute.

loading dose: 10 to 15 mg / kg IV slowly.

maintenance dose: 100 mg IV every 6 to 8 hours.

IM: Avoid the IM route because of erratic absorption.

Usual Adult Dose for Arrhythmias

Loading dose:

1.25 mg / kg IV every 5 minutes. Can repeat up to a loading dose of 15 mg / kg, or

250 mg orally 4 times a day for 1 day, then 250 mg twice daily for 2 days

Maintenance dosage:

300-400 mg / day orally in divided doses 1-4 times a day

Usual adult dose for status epilepticus

IV:

Loading dose: The manufacturer recommends 10 to 15 mg / kg by slow IV administration (at a rate of not more than 50 mg / minute). Alternatively, general guidelines suggest 15 to 20 mg / kg by slow IV administration (at a rate of not more than 50 mg / minute).

Maintenance level: 100 mg orally or IV every 6 to 8 hours

Maximum level: 50 mg / minute

Maintenance dose: IV or oral: 100 mg every 6 to 8 hours

Usual Adult Dose for Neurosurgery

Neurosurgery (prophylaxis): 100-200 mg IM at approximately 4 hour intervals during surgery and the immediate postoperative period. (Note: Although manufacturers recommend using IM, this route can cause severe local tissue damage and necrosis. Some doctors recommend using fosPhenytoin if IM use is required) If IM administration is not required, the accepted protocol has been 100 to 200 mg IV at about 4 hour intervals. during surgery and immediately after the postoperative period.

What is the dosage of Phenytoin for children?

Usual children's dose for seizures

Status epilepticus: Loading dose:

Infants, Children: 15 to 20 mg / kg IV in one or divided doses

Anticonvulsants: Loading dose:

All ages: 15 to 20 mg / kg orally (based on serum Phenytoin concentration and recent dose history). The oral load dose should be given in 3 divided doses given every 2 to 4 hours.

Anticonvulsants: Maintenance dose:

(IV or oral) (Note: it is possible that the dose is initially divided into daily doses in 3 doses / day, then adjusted according to individual needs.)

Less than or equal to 4 weeks: Initial: 5 mg / kg / day in 2 divided doses

Usual: 5-8 mg / kg / day IV divided in 2 doses (may require doses every 8 hours).

Greater than or equal to 4 weeks: Initial: 5 mg / kg / day in 2 to 3 divided doses

Usual: (may take up to every 8 hours of dosing)

6 months to 3 years: 8-10 mg / kg / day

4-6 years: 7.5-9 mg / kg / day

7-9 years: 7-8 mg / kg / day

10 to 16 years: 6-7 mg / kg / day

Usual children's dosage for Arrhythmias

Greater than 1 year:

Loading dose: 1.25 mg / kg IV every 5 minutes. Can repeat up to a loading dose of 15 mg / kg.

Loading dose: 5 to 10 mg / kg / day orally or IV in 2 to 3 divided doses.

In what dosage is Phenytoin available?

Capsule. Oral, sodium: 30 mg; 100 mg; 200 mg; 300 mg;

Solution, injection, sodium: 50 mg / mL

Suspension, oral: 125 mg / 5 mL (237 mL); 125 mg / 5 ml (4 mL, 237 mL)

Chewable tablet, oral: 50 mg

Phenytoin side effects

What side effects can be experienced due to Phenytoin?

Get emergency medical help if you have any of these signs of an allergic reaction: nausea, vomiting, sweating, hives, itching, difficulty breathing, swelling of your face, lips, tongue, or throat, or feel like you might pass out.

Report any new or worsening symptoms to your doctor, such as: changes in mood or behavior, depression, anxiety, or if you feel restless, irritable, restless, hyperactive (mental or physical), or have thoughts of suicide or hurting self.

Call your doctor if you have any of the following serious side effects:

• Fever, swollen glands, body aches, flu symptoms;
• Skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;
• Upper abdominal pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
• Chest pain, irregular heart rhythm, feeling short of breath;
• Confusion, nausea and vomiting, swelling, rapid weight gain, urinating less than usual or not at all;
• Cough with new and getting worse fever, difficulty breathing;
• Tremors (uncontrollable shaking), restless muscle movements in the eyes, tongue, jaw, or neck;
• Uneven skin tone, red spots, or a butterfly-shaped skin rash on the cheeks and nose (worsens in the sun); or
• Skin reactions - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially on the face or upper body) and causes blistering and peeling

Less serious side effects may include:

• Slurred speech, loss of balance or coordination;
• Gums are swollen or feel tender or
• Headache, dizziness, nervousness problems, or trouble sleeping (insomnia)

Not everyone experiences the following side effects. There may be some side effects not listed above. If you have concerns about certain side effects, consult your doctor or pharmacist.

Phenytoin Drug Warnings and Cautions

What should be known before using Phenytoin?

In deciding to use medication, the risks of taking the drug must be considered. It is up to you and your doctor. For this drug, the following should be considered:

Allergy

tell your doctor if you have ever had an unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to food, coloring, preservatives, or animals. For non-prescription products, read labels or ingredients carefully.

Children

Appropriate studies have not been conducted on the relationship of age to the effects of pregabalin in the pediatric population. Safety and efficacy have not been confirmed.

Elderly

The precise studies carried out to date have not shown specific problems that will limit the usefulness of Phenytoin injections in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require adjusting the dose for patients receiving Phenytoin injections.

Is Phenytoin safe for pregnant and breastfeeding women?

There is no adequate research on the risks of using this drug in pregnant or breastfeeding women. Always consult your doctor to weigh the potential benefits and risks before using this medication. This drug is included in the risk of pregnancy category D according to the US Food and Drug Administration (FDA).

The following references the pregnancy risk categories according to the FDA:

• A = Not at risk
• B = No risk in several studies
• C = May be risky
• D = There is positive evidence of risk
• X = Contraindicated
• N = Unknown

Studies in women show that this drug poses minimal risk to the baby when used during breastfeeding.

Phenytoin Drug Interactions

What medicines may interact with Phenytoin?

Drug interactions can change the performance of your medications or increase the risk of serious side effects. Not all possible drug interactions are listed in this document. Keep a list of all the products you use (including prescription / non-prescription drugs and herbal products) and consult your doctor or pharmacist. Do not start, stop, or change the dose of any medication without your doctor's approval.

Using this medication with any of the following medicines is not recommended. Your doctor may decide not to treat you with this drug or change some of the other medicines you take.

• Amifampridine
• Artemether
• Atazanavir
• Boceprevir
• Daclatasvir
• Delamanid
• Delavirdine
• Lurasidone
• Maraviroc
• Piperaquine
• Praziquantel
• Ranolazine
• Rilpivirine
• Telaprevir

Using this medication with any of the following medicines is not usually recommended, but may be necessary in some cases. If the two drugs are prescribed together, your doctor may change the dose or how often you use one or both drugs.

• Abiraterone Acetate
• Afatinib
• Apazone
• Apixaban
• Apremilast
• Aripiprazole
• Axitinib
• Beclamide
• Bedaquiline
• Bortezomib
• Bosutinib
• Bupropion
• Cabazitaxel
• Cabozantinib
• Canagliflozin
• Carbamazepine
• Ceritinib
• Clarithromycin
• Clozapine
• Cobicistat
• Crizotinib
• Cyclophosphamide
• Dabigatran Etexilate
• Dabrafenib
• Dasatinib
• Diazepam
• Diazoxide
• Dolutegravir
• Dopamine
• Doxorubicin
• Doxorubicin Hydrochloride Liposome
• Dronedarone
• Eliglustat
• Elvitegravir
• Enzalutamide
• Erlotinib
• Eslicarbazepine Acetate
• Ethosuximide
• Etravirine
• Everolimus
• Exemestane
• Ezogabine
• Fentanyl
• Fluvastatin
• Halothane
• Hydrocodone
• Ibrutinib
• Idelalisib
• Ifosfamide
• Imatinib
• Infliximab
• Irinotecan
• Itraconazole
• Ivabradine
• Ivacaftor
• Ixabepilone
• Ketoconazole
• Ketorolac
• Lapatinib
• Ledipasvir
• Lidocaine
• Linagliptin
• Lopinavir
• Macitentan
• Methotrexate
• Miconazole
• Mifepristone
• Netupitant
• Nifedipine
• Nilotinib
• Nimodipine
• Nintedanib
• Nitisinone
• Oritavancin
• Orlistat
• Pazopanib
• Perampanel
• Pixantrone
• Pomalidomide
• Ponatinib
• Posaconazole
• Regorafenib
• Reserpine
• Rifampin
• Rivaroxaban
• Rocuronium
• Roflumilast
• Romidepsin
• Sertraline
• Siltuximab
• Simeprevir
• Sofosbuvir
• Sorafenib
• St. John's Wort
• Sunitinib
• Tacrolimus
• Tasimelteon
• Tegafur
• Temsirolimus
• Theophylline
• Thiotepa
• Ticagrelor
• Tofacitinib
• Tolvaptan
• Trabectedin
• Ulipristal Acetate
• Vandetanib
• Vemurafenib
• Vilazodone
• Vincristine Sulfate
• Vincristine Sulfate Liposome
• Vinflunine
• Vorapaxar
• Voriconazole
• Vortioxetine

Using this medication with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If the two drugs are prescribed together, your doctor may change the dose or how often you use one or both drugs.

• Acetaminophen
• Acetazolamide
• Acyclovir
• Amiodarone
• Amitriptyline
• Amprenavir
• Aprepitant
• Atorvastatin
• Betamethasone
• Bexarotene
• Bleomycin
• Busulfan
• Capecitabine
• Carboplatin
• Caspofungin
• Chloramphenicol
• Cimetidine
• Ciprofloxacin
• Cisplatin
• Clobazam
• Clofazimine
• Clopidogrel
• Cortisone
• Cyclosporine
• Desogestrel
• Dexamethasone
• Dicumarol
• Dienogest
• Digitoxin
• Diltiazem
• Disopyramide
• Disulfiram
• Doxepin
• Drospirenone
• Estradiol Cypionate
• Estradiol Valerate
• Ethinyl Estradiol
• Ethynodiol Diacetate
• Etonogestrel
• Felbamate
• Fluconazole
• Fludrocortisone
• Fluorouracil
• Fluoxetine
• Fluvoxamine
• Folic Acid
• Fosamprenavir
• Gefitinib
• Ginkgo
• Ibuprofen
• Imipramine
• Isoniazid
• Levodopa
• Levomethadyl
• Levonorgestrel
• Levothyroxine
• Medroxyprogesterone Acetate
• Meperidine
• Mestranol
• Methoxsalen
• Methsuximide
• Midazolam
• Nafimidone
• Nelfinavir
• Nilutamide
• Nisoldipine
• Norelgestromin
• Norethindrone
• Norgestimate
• Norgestrel
• Ospemifene
• Oxcarbazepine
• Paclitaxel
• Pancuronium
• Paroxetine
• Phenprocoumon
• Piperine
• Prednisolone
• Prednisone
• Progabide
• Quetiapine
• Quinidine
• Quinine
• Remacemide
• Rifapentine
• Risperidone
• Rufinamide
• Sabeluzole
• Shankhapulshpi
• Simvastatin
• Sirolimus
• Sulfamethizole
• Sulfamethoxazole
• Sulfaphenazole
• Sulthiame
• Telithromycin
• Tenidap
• Tiagabine
• Ticlopidine
• Ticrynafen
• Tirilazad
• Tizanidine
• Tolbutamide
• Topiramate
• Trazodone
• Triamcinolone
• Trimethoprim
• Tubocurarine
• Valproic Acid
• Vecuronium
• Verapamil
• Vigabatrin
• Viloxazine

Can food or alcohol interact with Phenytoin?

Certain drugs should not be used with meals or when eating certain foods because drug interactions can occur. Consuming alcohol or tobacco with certain drugs can also cause interactions to occur. Discuss your use of drugs with food, alcohol, or tobacco with your health care provider.

What health conditions can interact with Phenytoin?

The presence of other health problems in your body may affect the use of this medicine. tell your doctor if you have other health problems such as:

• Blood or bone marrow problems (eg, agranulocytosis, leucopenia, thrombocytopenia) or
• Diabetes or
• Heart failure or
• Heart rhythm problems or
• Hypotension (low blood pressure) or
• Lymphadenopathy (lymph node problems) or
• Porphyria (enzyme problem) - Use with caution. It might make things worse.
• Heart block (for example, Adams-Stokes syndrome, AV blockage, or sinoatrial blockage) or
• Sinus bradycardia (slow heart rate) - should not be used in patients with this condition.
• Hypoalbuminemia (low albumin in the blood) or
• Kidney disease or
• Disease caution - Use with caution. The effect can be increased due to the slow cleansing of the drug from the body.

Phenytoin overdose

What should I do in an emergency or overdose?

In case of an emergency or overdose, contact the local emergency services provider (112) or immediately to the nearest hospital emergency department.

Overdose symptoms may include:

• Uncontrolled eye movements
• Loss of coordination
• slurred or slow speech
• Parts of the body that vibrate uncontrollably
• Nausea
• Gag
• Difficulty understanding reality
• Coma (loss of consciousness for a short period of time)

What should I do if I miss a dose?

If you forget a dose of this medicine, take it as soon as possible. However, when it is nearing the time of the next dose, skip the missed dose and return to the usual dosing schedule. Don't double the dose.