Asked by: Massin El Yaagoubi
medical health menopause

How does phenytoin work in the body?

Last Updated: 2nd January, 2020

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Phenytoin is an anti-epileptic drug, also called an anticonvulsant. Phenytoin works by slowing down impulses in the brain that cause seizures. Phenytoin is used to control seizures. It does not treat all types of seizures, and your doctor will determine if it is the right medicine for you.

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Correspondingly, how long does phenytoin take to work?

It usually takes around 4 weeks for phenytoin to work properly. This is because the dose of phenytoin needs to be increased slowly to prevent side effects. You may still have seizures or pain during this time.

Beside above, what can decrease effectiveness of phenytoin? Drugs that may decrease phenytoin levels and reduce effectiveness include carbamazepine, chronic alcohol abuse, reserpine, and sucralfate (Carafate).

Secondly, what are the side effects of phenytoin?

Side Effects. Headache, nausea, vomiting, constipation, dizziness, feeling of spinning, drowsiness, trouble sleeping, or nervousness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Phenytoin may cause swelling and bleeding of the gums.

What is Phenytoin 100mg used for?

Phenytoin is used to prevent and control seizures (also called an anticonvulsant or antiepileptic drug). It works by reducing the spread of seizure activity in the brain.

Related Question Answers

Tiffani Maresma

Professional

Does phenytoin make you sleepy?

Phenytoin oral capsule may cause drowsiness. This can slow your thinking and motor skills. You shouldn't drive, use machinery, or do other tasks that require alertness until you know how this drug affects you. Phenytoin can also cause other side effects.

Bouazzaoui Luddicke

Professional

Does phenytoin cause weight gain?

Weight gain or loss is not an integral part of epilepsy although a sedentary lifestyle can contribute to weight gain. AEDs associated with weight gain are gabapentin, pregabalin, valproic acid, and vigabatrin and possibly, carbamazepine. Weight neutral AEDs are lamotrigine, levetiracetam, and phenytoin.

Elenore Horne

Professional

What does phenytoin do to the brain?

Phenytoin is used to control certain type of seizures, and to treat and prevent seizures that may begin during or after surgery to the brain or nervous system. Phenytoin is in a class of medications called anticonvulsants. It works by decreasing abnormal electrical activity in the brain.

Noufissa Soares

Explainer

Does phenytoin cause weight loss?

Several antiepileptic drugs (AEDs) are associated with weight gain such as gabapentin, pregabalin, valproic acid, and vigabatrin and to some extent carbamazepine. Others are weight neutral such as lamotrigine, levetiracetam, and phenytoin or associated with slight weight loss as, e.g., felbamate.

Carley Gam

Explainer

Does phenytoin cause memory loss?

All drugs that depress signaling in the CNS can cause memory loss. Alternatives: Many patients with seizures do well on phenytoin (Dilantin), which has little if any impact on memory. Many patients with chronic nerve pain find that venlafaxine (Effexor) — which also spares memory — alleviates their pain.

Violet Manzke

Explainer

Does phenytoin affect blood pressure?

Phenytoin is an effective antiepileptic drug which is used for many years in the treatment of epileptic seizures. In previous decades, several patients experienced adverse effects of intravenous phenytoin such as severe heart arrhythmias and decrease of blood pressure.

Ademar Plisetsky

Pundit

Does phenytoin change urine color?

This medicine may cause the urine to turn pink or brown in colour. This is normal. Side effects can occur while taking phenytoin. Some of these are not serious and will go away with time or after the dose has been changed.

Sinforoso Heinnickel

Pundit

What are the long term side effects of phenytoin?

Side effects of phenytoin include sedation, a cerebellar syndrome, phenytoin encephalopathy, psychosis, locomotor dysfunction, hyperkinesia, megaloblastic anemia, decreased serum folate level, decreased bone mineral content, liver disease, IgA deficiency, gingival hyperplasia, and a lupus-like hypersensitivity syndrome

Zoryana Jazz

Pundit

What is a normal phenytoin level?

Although the reference range is between 10 and 20 µg/mL, about half of patients' seizures are controlled at values lower and higher than the therapeutic range. Some adverse effects of phenytoin are related to specific serum levels. Nystagmus is frequently observed at levels greater than 20 µg/mL.

Carme Jodecke

Pundit

Can phenytoin cause liver damage?

Phenytoin is an anticonvulsant that in rare cases can cause acute idiosyncratic drug-induced liver disease that can be severe or even fatal. The liver injury caused by phenytoin appears to be due to a hypersensitivity reaction and resembles cases of immunoallergic hepatotoxicity.

Dictina Caceiro

Pundit

What happens if phenytoin is low?

Phenytoin blood testing is ordered because phenytoin blood levels must be maintained within a narrow therapeutic range. If levels are too low, the affected person may experience seizures; if they are too high, the person may experience symptoms associated with phenytoin toxicity.

Rhea Benoist

Teacher

Can phenytoin cause heart problems?

As the key words, "phenytoin, diphenylhydantoin, epilepsy, seizure, cardiac toxicity, asystole, arrhythmia, respiratory arrest, hypotension, death" were used. Phenytoin is an effective and well tolerated drug in the treatment of epilepsy. Intravenous phenytoin is safe when given at recommended infusion rates and doses.

Gennie Lauerer

Teacher

What drugs interact with phenytoin?

Drugs That Affect Phenytoin Concentrations
Interacting Agent Examples
Drugs that may increase phenytoin serum levels
Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate
Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole
Antineoplastic agents Capecitabine, fluorouracil

Tarsila Corado

Teacher

What is phenytoin made of?

The chemical name is sodium 5,5-diphenyl-2, 4-imidazolidinedione, having the following structural formula: Each Dilantin— 100 mg Extended Oral Capsule—contains 100 mg phenytoin sodium. Also contains lactose monohydrate, NF; confectioner's sugar, NF; talc, USP; and magnesium stearate, NF.

Rolan Wilbert

Teacher

Can phenytoin be taken on an empty stomach?

This medicine can be taken with food or on an empty stomach. Try to take it the same way each day, since taking this with food may change the time it takes to be absorbed. Do not take antacids or medicine for diarrhea within 2 to 3 hours of taking phenytoin.

Viktors Kerzazi

Reviewer

What does high phenytoin level mean?

The neurotoxic effects are concentration dependent and can range from mild nystagmus to ataxia, slurred speech, vomiting, lethargy and eventually coma and death. Paradoxically, at very high concentrations, phenytoin can lead to seizures. Greater than 50 mg/L: Coma and seizures.

Jarmila Groskov

Reviewer

What is phenytoin toxicity?

What is Dilantin toxicity? Dilantin, or phenytoin, toxicity happens when you have high levels of Dilantin in your body that become harmful. Dilantin is a medicine that is used to prevent and treat seizures. Dilantin toxicity can lead to a coma.

Yariza Etna

Reviewer

How is phenytoin cleared?

Elimination occurs primarily by biotransformation to several inactive hydroxylated metabolites. Metabolites are then mostly excreted in the urine. Phenytoin follows nonlinear (or zero-order) kinetics at therapeutic concentrations, because the rate of metabolism is close to the maximum capacity of the enzymes involved.

Aditya Reinisch

Reviewer

What is the trade name for phenytoin?

Phenytoin. Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication.