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Anticonvulsant, succinimide (Oral route)

Brand Names:

  • Ativan
  • Banzel
  • Carbatrol
  • Celontin Kapseals
  • Depakene
  • Depakote
  • Diamox Sequels
  • Dilantin
  • Diphen
  • Felbatol
  • Gabitril
  • Gen-Xene
  • Keppra
  • Klonopin
  • Lamictal
  • Lyrica
  • Mebaral
  • Mesantoin
  • Mysoline
  • Neurontin
  • Peganone
  • Seconal
  • Topamax
  • Trileptal
  • Vimpat
  • Zarontin
  • Zonegran
  • Alti-Valproic
  • Dilantin-125
  • Dilantin-30
  • Milontin
  • Sabril
  • Tegretol

Dosage Forms:

  • Tablet, Delayed Release
  • Capsule
  • Elixir
  • Tablet, Disintegrating
  • Solution
  • Tablet
  • Capsule, Extended Release
  • Capsule, Delayed Release
  • Capsule, Liquid Filled
  • Tablet, Chewable
  • Tablet, Extended Release
  • Tablet, Enteric Coated
  • Suspension
  • Syrup
  • Liquid
  • Powder

Uses of This Medicine:

Succinimide anticonvulsants are used to control certain seizures in the treatment of epilepsy. These medicines act on the central nervous system (CNS) to reduce the number and severity of seizures.

This medicine is available only with your doctor's prescription.

Before Using This Medicine:


Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Succinimide anticonvulsants are not expected to cause different side effects or problems in children than they do in adults.

Older adults

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of succinimide anticonvulsants in the elderly to use in other age groups, they are not expected to cause different side effects or problems in older people than they do in younger adults.


Although succinimide anticonvulsants have not been shown to cause problems in humans, there have been unproven reports of increased birth defects associated with the use of other anticonvulsant medicines.


Ethosuximide passes into breast milk. It is not known whether methsuximide passes into breast milk. However, these medicines have not been reported to cause problems in nursing babies.

Other medicines

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

  • Clorgyline
  • Disulfiram
  • Iproniazid
  • Isocarboxazid
  • Moclobemide
  • Nefazodone
  • Nialamide
  • Pargyline
  • Phenelzine
  • Procarbazine
  • Ranolazine
  • Selegiline
  • Toloxatone
  • Tranylcypromine
  • Voriconazole

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

  • Acenocoumarol
  • Adenosine
  • Adinazolam
  • Alfentanil
  • Alprazolam
  • Amobarbital
  • Anileridine
  • Anisindione
  • Apazone
  • Aprobarbital
  • Arsenic Trioxide
  • Beclamide
  • Bromazepam
  • Brotizolam
  • Buprenorphine
  • Butabarbital
  • Butalbital
  • Carbamazepine
  • Carisoprodol
  • Chloral Hydrate
  • Chlordiazepoxide
  • Chlorzoxazone
  • Clobazam
  • Clonazepam
  • Clorazepate
  • Clozapine
  • Codeine
  • Dantrolene
  • Darunavir
  • Dasatinib
  • Delavirdine
  • Diazepam
  • Dicumarol
  • Digitalis
  • Doripenem
  • Droperidol
  • Erlotinib
  • Ertapenem
  • Estazolam
  • Ethchlorvynol
  • Ethinyl Estradiol
  • Etravirine
  • Fentanyl
  • Flunitrazepam
  • Flurazepam
  • Fospropofol
  • Gestodene
  • Halazepam
  • Hydrocodone
  • Hydromorphone
  • Imatinib
  • Imipenem
  • Irinotecan
  • Itraconazole
  • Ixabepilone
  • Ketazolam
  • Lamotrigine
  • Lapatinib
  • Levomethadyl
  • Levorphanol
  • Licorice
  • Lidocaine
  • Lopinavir
  • Lorazepam
  • Lormetazepam
  • Maraviroc
  • Medazepam
  • Meperidine
  • Mephenesin
  • Mephobarbital
  • Meprobamate
  • Meropenem
  • Metaxalone
  • Methocarbamol
  • Methohexital
  • Methotrexate
  • Methoxyflurane
  • Midazolam
  • Morphine
  • Morphine Sulfate Liposome
  • Nelfinavir
  • Nilotinib
  • Nitrazepam
  • Nordazepam
  • Oxazepam
  • Oxycodone
  • Oxymorphone
  • Pentobarbital
  • Phenindione
  • Phenobarbital
  • Phenprocoumon
  • Posaconazole
  • Prazepam
  • Primidone
  • Propoxyphene
  • Proscillaridin
  • Quazepam
  • Quetiapine
  • Quinidine
  • Remifentanil
  • Secobarbital
  • Sirolimus
  • Sodium Oxybate
  • Sotalol
  • St John's Wort
  • Sufentanil
  • Sunitinib
  • Tacrolimus
  • Temazepam
  • Temsirolimus
  • Teniposide
  • Thiopental
  • Tramadol
  • Triazolam
  • Valproic Acid
  • Vigabatrin
  • Voriconazole
  • Vorinostat

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other medical problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

  • Blood disease or
  • Intermittent porphyria or
  • Kidney disease (severe) or
  • Liver disease Succinimide anticonvulsants may make the condition worse.

Proper Use of This Medicine:

This medicine must be taken every day in regularly spaced doses as ordered by your doctor. Do not take more or less of it than your doctor ordered.

If this medicine upsets your stomach, take it with food or milk unless otherwise directed by your doctor.


The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (capsules or syrup):
    • As an anticonvulsant:
      • Adults and children 6 years of age and over To start, 250 milligrams (mg) twice a day. Your doctor may increase your dose gradually if needed. However, the dose is usually not more than 1500 mg a day.
      • Children up to 6 years of age To start, 250 mg once a day. Your doctor may increase your dose gradually if needed. However, the dose is usually not more than 1000 mg a day.
  • For oral dosage form (capsules):
    • As an anticonvulsant:
      • Adults, teenagers, and children To start, 300 milligrams (mg) once a day. Your doctor may increase your dose gradually if needed. However, the dose is usually not more than 1200 mg a day.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

If you miss a dose of this medicine, take it as soon as possible. However, if it is within 4 hours of your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Keep out of the reach of children.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Do not keep outdated medicine or medicine no longer needed.

Keep the liquid form of this medicine from freezing. Do not refrigerate.

Precautions While Using This Medicine:

Your doctor should check your progress at regular visits, especially during the first few months of treatment with this medicine. During this time the amount of medicine you are taking may have to be changed often to meet your individual needs.

If you have been taking a succinimide anticonvulsant regularly, do not stop taking it without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are taking before stopping completely. Stopping this medicine suddenly may cause seizures.

Do not start or stop taking any other medicine without your doctor's advice. Other medicines may affect the way this medicine works.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

This medicine may cause some people to become drowsy or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert. After you have taken this medicine for a while, this effect may lessen.

Before having any kind of surgery, dental treatment, or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine. Taking succinimide anticonvulsants together with medicines that are used during surgery or dental or emergency treatments may increase the CNS depressant effects

Your doctor may want you to carry a medical identification card or bracelet stating that you are taking this medicine.

For patients taking methsuximide:

  • Do not use capsules that are not full or in which the contents have melted, because they may not work properly.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

More common
Muscle pain
skin rash and itching
swollen glands
sore throat and fever
Less common
difficulty in concentration
mental depression
increased chance of certain types of seizures
mood or mental changes
nosebleeds or other unusual bleeding or bruising
shortness of breath
sores, ulcers, or white spots on lips or in mouth
unusual tiredness or weakness
wheezing, tightness in chest, or troubled breathing
Symptoms of overdose
Drowsiness (severe)
nausea and vomiting (severe)
troubled breathing

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
Clumsiness or unsteadiness
loss of appetite
nausea or vomiting
stomach cramps
Less common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Last Updated: 6/12/2013
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