phenytoin

An anticonvulsant drug, C₁₅H₁₂N₂O₂, used most commonly in the treatment of epilepsy. Also called diphenylhydantoin.

[(DI)PHENY(LHYDAN)TOIN.]

Key Terms: Anticonvulsant, Bipolar disorder, Epilepsy, Lymph system.

Definition

Phenytoin is an anticonvulsant, a drug that acts to prevent seizures. In the United States, phenytoin is sold under the brand name Dilantin.

Purpose

Phenytoin helps prevent some types of seizure activity. It is often used to aid in controlling nerve pain associated with some cancers and cancer treatments. Nerve pain causes a burning, tingling sensation. Phenytoin also may be ordered to control a rapid or irregular heart rate. Phenytoin may be given to stop uncontrolled seizures. It may be used during brain surgery to prevent seizure activity. In 2003 a group of researchers in California reported that phenytoin is effective in controlling the acute mania associated with bipolar disorder. Additional uses are under study.

Description

Phenytoin works on areas of the brain to limit electrical discharges and stabilize cellular activity. Like many drugs that control seizures, it also has proven helpful in managing nerve pain.

Recommended Dosage

The dose ordered depends on blood levels of the drug determined during routine monitoring. For pain, doctors usually order 200–500 mg per day, either at bedtime or in divided doses. Patients usually start on a low dose. Depending on the patient's response and drug blood levels, the dose may be increased. For seizures, patients are usually started at 100 mg, three times per day. Blood is drawn to check the level of phenytoin in seven to 10 days. The dose is adjusted accordingly. The doctor may prescribe a dose based on an older person's weight. A child's dose also is based on his or her weight.

It is very important that this drug be used exactly as directed. This medication should be taken at the same time every day. Patients should take a missed dose as soon as it is noted. But patients should not take two doses within four hours of each other. This medication should be stored in a dry place, not in the bathroom.

Precautions

Patients should not suddenly stop taking this medication. The abrupt withdrawal of phenytoin could trigger seizures. Patients should not crush or break extended-release drugs. Chewable tablets should be chewed before swallowing. Other pills should be swallowed whole. Older adults may be more prone to adverse effects than younger people. Patients should not change brands without approval of the doctor.

Phenytoin should not be taken by patients who are allergic to this drug. People with slow heart rates, certain other heart conditions, or a flaking, open skin condition also should not take it. Phenytoin may be used cautiously for patients with asthma, allergies, limited kidney or liver function, heart disease, and blood disorders. It also should be used with caution in those with alcoholism, diabetes mellitus, lupus, poor thyroid function, or porphyria, a rare metabolic disorder. Pregnant women should discuss the risks and benefits of this medication with the doctor. It has been associated with birth defects and possibly cancer in children born to women taking the drug; one study done in 2003 suggests that phenytoin interferes with the normal development of the baby's blood circulation. Expectant mothers who are taking it to prevent seizures should not abruptly stop the drug. Those using it for pain control should discuss its continued use with the doctor. Patients on this drug should not breast feed.

Side Effects

Drowsiness is a common side effect of phenytoin. Patients should exercise caution when driving or operating machinery. Alcohol may increase drowsiness. Patients should not consume alcoholic beverages while taking this drug. Other, less frequent effects related to the central nervous system include an unsteady gait, slurred speech, confusion, and dizziness. Patients may experience depression, difficulty sleeping, nervousness, irritability, tremors, and numbness. Twitching, headache, mental-health problems including psychotic episodes, and more seizure activity may occur. This medication may also cause nausea and vomiting, stomach upset, diarrhea, constipation, and swollen gum tissue. Side effects also include a rash, hair loss (alopecia) or excessive hair growth, vision changes, uncontrolled eye movements, and inflammation of the surface of the eye. Patients may develop chest pain, swelling, fever, increase in weight, enlarged lips, or joint or muscle pain. Patients should practice good dental hygiene to decrease the risk of gum disease. With the doctor's approval, it may be taken with food to decrease stomach upset.

Phenytoin may produce changes in the normal makeup of the blood, including high blood sugar levels and anemia. It may trigger disorders of the lymphatic system and cause liver damage. If the liver is not able to properly break down phenytoin, it can produce toxic effects, even at small doses. Doctors typically assess kidney and liver function prior to ordering it. The tests are repeated at regular intervals. Patients should notify the doctor promptly of any side effects. If a skin rash develops, the doctor will instruct the patient how to taper off and stop the drug.

Interactions

Many drugs interact with phenytoin and may increase or decrease its blood levels. Phenytoin may alter the effectiveness of other drugs. The list of interactions is long and varied. Drugs that interfere with phenytoin include anticoagulants (blood thinners), sulfa and other antibiotics, antifungal agents, drugs used to treat ulcers, methadone, antidepressants, and disulfiram, which is used to treat alcoholism. It also interacts with corticosteroids, estrogen hormones, birth control pills and injections, drugs to treat hypoglycemia, asthma drugs, such other anticonvulsants as carbamazepine, lidocaine, heart medications, Parkinson's disease drugs, anti-inflammatory drugs, narcotic pain relievers, and anticancer drugs. Additionally, taking phenytoin with certain antidepressants may cause seizures in some patients.

Phenytoin has also been reported to interact with certain herbs, including evening primrose (Oenothera biennis), gingko (Gingko biloba), wormwood (Artemisia pontica), and an Ayurvedic preparation known as Shankapulshpi. Patients should always tell their doctors about any herbal preparations they may be taking as well as other prescription medications.

Alcohol ingestion can interfere with maintaining proper blood levels of phenytoin. Patients should not drink alcoholic beverages while taking this medication, as phenytoin can accumulate to toxic levels in the body of non-compliant patients. Antacids and calcium can lower the effectiveness of phenytoin. These drugs should be taken two to three hours apart from phenytoin. Tube feeding may decrease the amount of phenytoin absorbed. Patients should not give tube feedings for two hours before and after taking this drug. Patients should talk to the doctor before taking folic acid. It may interfere with this drug.

Resources

Periodicals

Akula, R., S. Hasan, R. Pipalla, and C. Ferguson. "Noncompliance Leading to Drug Accumulation Resulting in Phenytoin Toxicity." Journal of the National Medical Association 95 (December 2003): 1201–1203.

Gatzonis, S. D., E. Angelopoulos, P. Sarigiannis, et al. "Acute Psychosis Due to Treatment with Phenytoin in a Nonepileptic Patient." Epilepsy and Behavior 4 (December 2003): 771–772.

Lyon, H. M., L. B. Holmes, and T. Huang. "Multiple Congenital Anomalies Associated with In Utero Exposure of Phenytoin: Possible Hypoxic Ischemic Mechanism?" Birth Defects Research, Part A: Clinical and Molecular Teratology 67 (December 2003): 993–996.

Misra, U. K., J. Kalita, and C. Rathore. "Phenytoin and Carbamazepine Cross-Reactivity: Report of a Case and Review of Literature." Postgraduate Medical Journal 79 (December 2003): 703–704.

Wang, P. W., T. A. Ketter, O. V. Becker, and C. Nowakowska. "New Anticonvulsant Medication Uses in Bipolar Disorder." CNS Spectrums 8 (December 2003): 930–2, 941–7.

Organizations

United States Food and Drug Administration (FDA). 5600 Fishers Lane, Rockville, MD 20857-0001. (888) INFO-FDA (463-6332). .

—Debra Wood, R.N.; Rebecca J. Frey, Ph.D.

Brand names: Dilantin®Dilantin® Infatabs®Phenytek™

Chemical formula:

Drug Forms:
• Phenytoin Oral suspension (below)
• Phenytoin Sodium Solution for injection
• Phenytoin oral suspension
• Phenytoin Chewable tablet
• Phenytoin Sodium Oral capsule
• Phenytoin Sodium Oral capsule, extended-release

Español:
• Fenitoína, Suspensión oral
• Fenitoína Sódica, Solución para inyección
• Suspensión oral de fenitoína
• Fenitoína, Tableta masticable
• Fenitoína Sódica, Cápsula oral
• Fenitoína Sódica, Cápsula oral de liberación prolongada

Phenytoin Oral suspension

What is this medicine?

PHENYTOIN is used to control seizures in certain types of epilepsy.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
•an alcohol abuse problem
•Asian ancestry
•blood disorders or disease
•diabetes
•heart problems
•kidney disease
•liver disease
•porphyria
•receiving radiation therapy
•suicidal thoughts, plans, or attempt; a previous suicide attempt by you or a family member
•thyroid disease
•an unusual or allergic reaction to phenytoin, other medicines, foods, dyes, or preservatives
•pregnant or trying to get pregnant
•breast-feeding

How should I use this medicine?

Take this medicine by mouth. Follow the directions on the prescription label. Shake the bottle well before each dose. Use a specially marked spoon or dropper to measure your medicine. Ask your pharmacist if you do not have one. Household spoons are not accurate. Take this medicine with food if it upsets your stomach. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking this medicine suddenly. This increases the risk of seizures. Your doctor will tell you how much medicine to take. If your doctor wants you to stop the medicine, the dose will be slowly lowered over time to avoid any side effects.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
•delavirdine

This medicine may also interact with the following medications:
•alcohol
•aspirin and aspirin-like medicines
•barbiturate medicines for inducing sleep or treating seizures
•calcium supplements
•carbamazepine
•chloramphenicol
•chlordiazepoxide
•cimetidine or other medicines for heartburn or stomach ulcers
•corticosteroid hormones such as prednisone or cortisone
•diazepam
•disulfiram
•doxycycline
•enteral feedings (liquid nutritional drinks or tube feeding liquids)
•ethosuximide
•female hormones, including contraceptive or birth control pills
•furosemide
•halothane
•isoniazid
•medicines for mental depression, anxiety or other mood problems
•medicines to control heart rhythm
•methsuximide
•methylphenidate
•molindone
•phenylbutazone
•reserpine
•rifampin, rifabutin or rifapentine
•sucralfate
•sulfonamides like Azulfidine or Bactrim
•theophylline
•ticlopidine
•tolbutamide
•valproic acid
•vitamin D
•warfarin

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular checks on your progress. This medicine needs careful monitoring. Your doctor or health care professional may schedule regular blood tests.
 
Wear a medical ID bracelet or chain, and carry a card that describes your disease and details of your medicine and dosage times.
 
Do not change brands or dosage forms of this medicine without discussing the change with your doctor or health care professional.
 
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
 
Birth control pills may not work properly while you are taking this medicine. Talk to your doctor about using an extra method of birth control.
 
This medicine can cause unusual growth of gum tissues. Visit your dentist regularly. Problems can arise if you need dental work, and in the day to day care of your teeth. Try to avoid damage to your teeth and gums when you brush or floss your teeth.
 
Do not take antacids at the same time as this medicine. If you get an upset stomach and want to take an antacid or medicine for diarrhea, make sure there is an interval of 2 to 3 hours before or after you took your phenytoin.
 
The use of this medicine may increase the chance of suicidal thoughts or actions. Pay special attention to how you are responding while on this medicine. Any worsening of mood, or thoughts of suicide or dying should be reported to your health care professional right away.
 
Women who become pregnant while using this medicine may enroll in the North American Antiepileptic Drug Pregnancy Registry by calling 1-888-233-2334. This registry collects information about the safety of antiepileptic drug use during pregnancy.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
•allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
•breathing problems
•changes in vision
•chest pain or tightness
•confusion
•dark yellow or brown urine
•fast or irregular heartbeat
•fever, sore throat
•headache
•loss of seizure control
•poor control of body movements or difficulty walking
•redness, blistering, peeling or loosening of the skin, including inside the mouth
•unusual bleeding or bruising, pinpoint red spots on skin
•vomiting
•worsening of mood, thoughts or actions of suicide or dying
•yellowing of the eyes or skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
•constipation
•difficulty sleeping
•excessive hair growth on the face or body
•nausea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Do not freeze. Protect from light. Throw away any unused medicine after the expiration date.

Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.

An anticonvulsant used as the sodium salt. Occasionally used in the treatment of tonic–clonic and psychomotor seizures; also used for the control of cardiac arrhythmias, especially those caused by digitalis intoxication. Formerly called diphenylhydantoin.

Phenytoin
Systematic (IUPAC) name
5,5-diphenylimidazolidine-2,4-dione
Identifiers
CAS number	57-41-0
ATC code	N03AB02 N03AB04, N03AB05
PubChem	1775
DrugBank	APRD00241
ChemSpider	1710
Chemical data
Formula	C15H12N2O2
Mol. mass	252.268 g/mol
Pharmacokinetic data
Bioavailability	70-100% oral, 24.4% for rectal and intravenous administration
Protein binding	90%
Metabolism	hepatic
Half life	6-24 hours
Excretion	Primarily through the bile, urinary
Therapeutic considerations
Pregnancy cat.	D
Legal status
Routes	Oral, parenteral

Phenytoin sodium is a commonly used antiepileptic. Phenytoin acts to dampen the unwanted, runaway brain activity seen in seizure by reducing electrical conductance among brain cells by stabilizing the inactive state of voltage gated sodium channels. Aside from seizures, it is an option in the treatment of trigeminal neuralgia as well as certain cardiac arrhythmias.

It is sometimes considered a class 1b antiarrhythmic.^[1]

Contents 1 Trade names 2 History 3 Side-effects 3.1 Neurologic 3.2 Hematologic 3.3 Teratogenicity 3.4 Carcinogenicity 3.5 Gingival 3.6 Suicide risk 3.7 In autoimmune disease 4 See also 5 References 6 External links

Trade names

Phenytoin sodium has been marketed as Phenytek by Mylan Laboratories, previously Bertek Pharmaceuticals, and Dilantin; Australia also Dilantin Kapseals and Dilantin Infatabs in the USA, Eptoin by Abbott Group in India and as Epanutin in the UK and Israel, by Parke-Davis, now part of Pfizer. In the USSR and post-USSR countries, it was/is marketed as Дифенин (Diphenin, Dipheninum), PhydumTM in form of tab./inj. by Quadra labs pvt. ltd. in India.

History

Phenytoin (diphenylhydantoin) was first synthesized by German chemist Heinrich Biltz in 1908. Biltz sold his discovery to Parke-Davis, which did not find an immediate use for it. In 1938, outside scientists including H. Houston Merritt and Tracy Putnam discovered phenytoin's usefulness for controlling seizures, without the sedative effects associated with phenobarbital.

According to Goodman and Gilman's Pharmacological Basis of Therapeutics,

In contrast to the earlier accidental discovery of the antiseizure properties of bromide and phenobarbital, phenytoin was the product of a search among nonsedative structural relatives of phenobarbital for agents capable of suppressing electroshock convulsions in laboratory animals.^[2]

There are some indications that phenytoin has other effects, including anxiety control and mood stabilization, although it has never been approved for those purposes by the FDA. Jack Dreyfus, founder of the Dreyfus Fund, became a major proponent of phenytoin as a means to control nervousness and depression when he received a prescription for Dilantin in 1966. Notably, he is believed to have supplied large amounts of the drug to Richard Nixon throughout the late 1960s and early 1970s. Dreyfus' experience with phenytoin is outlined in his book, A Remarkable Medicine Has Been Overlooked,^[3]. Despite more than $70 million in personal financing, his push to see phenytoin evaluated for alternative uses has had little lasting effect on the medical community. This was partially because Parke-Davis was reluctant to invest in a drug nearing the end of its patent life, and partially due to mixed results from various studies.

It was approved by the USA Food and Drug Administration in 1953 for use in seizures.

Dilantin made an appearance in the 1962 novel One Flew Over the Cuckoo's Nest by Ken Kesey, both as an anticonvulsant and as a mechanism to control inmate behavior.

In 2008 the drug was put on the FDA'sPotential Signals of Serious Risks List to be further evaluated for approval. The list means that the FDA has identified a potential safety issue, but does not mean that FDA has identified a causal relationship between the drug and the listed risk.

According to the FDA's New Safety Information Identified by the Adverse Event Reporting System (AERS) Phenytoin Injection (Dilantin) has been associated with the risk of Purple Glove Syndrome.

Side-effects

Neurologic

At therapeutic doses, phenytoin produces horizontal gaze nystagmus, which is harmless but occasionally tested for by police as a marker for alcohol intoxication (which can also produce nystagmus). At toxic doses, patients experience sedation, cerebellar ataxia, and ophthalmoparesis, as well as paradoxical seizures. Idiosyncratic side effects of phenytoin, as with other anticonvulsants, include rash and severe allergic reactions.

Phenytoin may accumulate in the cerebral cortex over long periods of time, as well as causing atrophy of the cerebellum when administered at chronically high levels. Despite this, the drug has a long history of safe use, making it one of the more popular anti-convulsants prescribed by doctors, and a common "first line of defense" in seizure cases.

Hematologic

It has been suggested that phenytoin causes a reduction in folic acid levels, predisposing patients to megaloblastic anemia. Folic acid is presented in foods as polyglutamate, which is then converted into monoglutamates by intestinal conjugase. Phenytoin acts by inhibiting this enzyme therefore causing folate deficiency.^[4]

Teratogenicity

Phenytoin is a known teratogen. The syndrome consists of craniofacial anomalies (broad nasal bridge, cleft lip and palate, microcephaly) and a mild form of mental retardation (average IQ=71).^[5] This syndrome resembles the well-described Fetal Alcohol Syndrome^[6] and has also been called the "fetal hydantoin syndrome."

Recently, the teratogenicity of phenytoin has been contested.^{[citation needed]} One blinded trial asked physicians to separate photographs of children into two piles based on whether they showed the so-called characteristic features of this syndrome; it found that physicians were no better at diagnosing the syndrome than would be expected by random chance, calling the very existence of the syndrome into question.^{[citation needed]} Data now being collected by the Epilepsy and Antiepileptic Drug Pregnancy Registry may one day answer this question definitively.

Some recommend avoiding polytherapy and maintaining the minimal dose possible during pregnancy, but acknowledge that current data do not provide clear answers.^[7]

Carcinogenicity

There is no good evidence that phenytoin is a human carcinogen.^{[8] [9]}

Gingival

Phenytoin has been associated with drug induced gingival enlargement (hyperplasia) in the oral cavity probably due to above mentioned folate defiency. Plasma concentrations needed to induce gingival lesions has not been clearly defined. Effects consist of the following: bleeding upon probing, increased gingival exudate, pronounced gingival inflammatory response to plaque levels, associated in some instances with bone loss but without tooth detachment.

Suicide risk

Following almost 200 studies of 11 anti-seizure drugs, the FDA has also warned of an increased suicide risk for any patients treated with certain anti-seizure drugs. The study of 44,000 patients found that patients whose epilepsy is treated with drugs face about twice the risk of suicidal thoughts compared to placebo-takers. Although phenytoin was not named in the study, the FDA announced that it expected the risk applied to every epilepsy drug.^[10]

In autoimmune disease

Phenytoin has been known to cause drug-induced lupus.^[11]

Phenytoin therapy has been linked to the life-threatening skin reactions Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). These conditions are significantly more common in patients with a particular HLA-B allele, HLA-B*1502.^[12] This allele occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians.

See also

• hydantoins
• fosphenytoin
• mephenytoin
• ethotoin

References

1. ^ Balaji S (October 2004). "Medical therapy for sudden death". Pediatr. Clin. North Am. 51 (5): 1379–87. doi:10.1016/j.pcl.2004.04.002. PMID 15331289. http://linkinghub.elsevier.com/retrieve/pii/S0031395504000513. 
2. ^ Goodman and Gilman's Pharmacological Basis of Therapeutics, 10th ed. (New York: McGraw-Hill, 2001).
3. ^ Dreyfus, Jack (1998). A Remarkable Medicine Has Been Overlooked: Including an Autobiography and the Clinical Section of the Broad Range of Use of Phenytoin. Continuum International Publishing Group. ISBN 0-8264-1069-3. 
4. ^ Carl GF, Smith ML. (1995). Phenytoin-folate interactions: differing effects of the sodium salt and the free acid of phenytoin. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1547769&dopt=Abstract.
5. ^ Beckmann, Charles R, et al. Obstetrics and Gynecology. 4th Ed. Baltimore: Lippincott Williams & Wilkins, 2002.
6. ^ CDC. (2004). Fetal Alcohol Syndrome: Guidelines for Referral and Diagnosis. Can be downloaded at http://www.cdc.gov/fas/faspub.htm.
7. ^ Adab N, Tudur SC, Vinten J, Williamson P, Winterbottom J (2004). "Common antiepileptic drugs in pregnancy in women with epilepsy". Cochrane Database Syst Rev (3): CD004848. doi:10.1002/14651858.CD004848. PMID 15266543. 
8. ^ Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-216.
9. ^ Maeda T, Sano N, Togei K, Shibata M, Izumi K, Otsuka H (1988). "Lack of carcinogenicity of phenytoin in (C57BL/6 x C3H)F1 mice". J Toxicol Environ Health 24 (1): 111–9. PMID 3373561. 
10. ^ FDA warns of risks from epilepsy drugs.. http://news.yahoo.com/s/ap/20080201/ap_on_he_me/epilepsy_drugs
11. ^ Scheinfeld N (August 2003). "Phenytoin in cutaneous medicine: its uses, mechanisms and side effects". Dermatol. Online J. 9 (3): 6. PMID 12952753. http://dermatology.cdlib.org/93/reviews/dilantin/scheinfeld.html. 
12. ^ Man CB, Kwan P, Baum L, et al. (May 2007). "Association between HLA-B*1502 allele and antiepileptic drug-induced cutaneous reactions in Han Chinese". Epilepsia 48 (5): 1015–8. doi:10.1111/j.1528-1167.2007.01022.x. PMID 17509004. 

External links

• Medicines for Epilepsy: Dilantin Epilepsy Foundation.
• Remarkable Medicine, a website about the Dreyfus Foundation's work to expand the indications for phenytoin
• Phenytoin Pharmacokinetics

v • d • e Anticonvulsants (N03) GABAA receptor agonist Barbiturates Barbexaclone · Metharbital · Methylphenobarbital · Pentobarbital · Phenobarbital · Primidone Benzodiazepines Clobazam · Clonazepam · Clorazepate · Diazepam · Flutoprazepam · Lorazepam · Midazolam · Nimetazepam · Nitrazepam · Temazepam Other GABA agents Aromatic allylic alcohols Stiripentol Carbonic anhydrase inhibitor Sulfa drugs Acetazolamide · Ethoxzolamide · Sultiame · Zonisamide Channel blockers Primarily sodium Hydantoins Ethotoin · Fosphenytoin · Mephenytoin · Phenytoin Carboxamides Carbamazepine · Eslicarbazepine acetate · Oxcarbazepine · Rufinamide Primarily calcium Succinimides Ethosuximide · Mesuximide · Phensuximide Unknown/ungrouped Phenyltriazines Lamotrigine Oxazolidinediones Ethadione · Paramethadione · Trimethadione Ureas Phenacemide · Pheneturide Monosaccharides Topiramate Indirect GABA agents Carboxylic acids/ Fatty acid derivatives GABA transaminase inhibitor: Valproic acid (Sodium valproate & Valproate semisodium) · Valpromide · Valnoctamide GABA reuptake inhibitor: Tiagabine GABA analogs Gabapentin · Pregabalin · Progabide · Vigabatrin Unknown/multiple/ unsorted Carbamates Emylcamate · Felbamate · Meprobamate · Carisbamate Pyrrolidines Brivaracetam · Levetiracetam · Nefiracetam · Seletracetam Propionates Beclamide · Lacosamide Aldehydes Paraldehyde Bromides Potassium bromide · Sodium bromide

v • d • e Antiarrhythmic agents (C01B) Channel blockers class I (Na+ channel blockers) class Ia (Phase 0→ and Phase 3→) Procainamide # • Quinidine # • Ajmaline • Disopyramide • Prajmaline • Sparteine class Ib (Phase 3←) IV (Lidocaine #) • enteral (Mexiletine, Tocainide, Aprindine) class Ic (Phase 0→) Encainide • Flecainide • Lorcainide • Moricizine • Propafenone class III (Phase 3→, K+ channel blockers) Amiodarone • Bretylium • Bunaftine • Dofetilide • Ibutilide • Nifekalant • Sotalol • Tedisamil • E-4031 class IV (Phase 4→, Ca2+ channel blockers) Verapamil # • Diltiazem Receptor agonists and antagonists class II (Phase 4→, β blockers) Propranolol • Nadolol • Pindolol • cardioselective (Atenolol, Metoprolol, Acebutolol, Esmolol) A1 agonist Adenosine M2 muscarinic antagonist: Atropine • Quinidine • Disopyramide muscarinic agonist: Digoxin α receptors Quinidine • Verapamil • Amiodarone • Bretylium Ion transporters Na+ / K+-ATPase Digoxin # = WHO-EM

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)