This information is intended for use by health professionals
Ethosuximide Essential Generics 250 mg Capsules
Each capsule contains 250 mg ethosuximide.
Excipient with known effect
Each capsule contains 0.60 mg sodium ethyl hydroxybenzoate, 0.60 mg sodium propyl hydroxybenzoate and traces of soya lecithin
For the full list of excipients, see section 6.1.
The capsules are clear oval soft gelatin capsules.
Ethosuximide 250 mg Capsules gives selective control of absence seizures (petit mal) even when complicated by grand mal.
It is also indicated for myoclonic seizures.
Adults, the Elderly and Children over 6 Years
Start with a small dose - 500mg daily with increments of 250mg every five to seven days until control is achieved with 1000 - 1500 mg daily. Occasionally 2000 mg in divided doses may be necessary.
Paediatric population aged 0-6 years
Children aged 0-6 years old and those who are unable to swallow capsules should be given ethosuximide oral liquid. Currently available clinical trial data regarding the use of ethosuximide in the paediatric population are described in section 5.1.
Effective plasma levels of ethosuximide normally lie between 40 and 100 mcg per ml, but the clinical response should be the criteria for the regulation of the dosage. The half-life of ethosuximide in the plasma is more than 24 hours but the daily dose if large is more comfortably divided between morning and evening.
Method of administration
For oral use.
• Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
• Hypersensitivity to succinimides.
• Hypersensitivity to soya oil (see section 4.4).
Suicidal ideation and behaviour have been reported in patients treated with anti-epileptic agents in several indications. A meta-analysis of randomised placebo controlled trials of anti-epileptic drugs has also shown a small increased risk of suicidal ideation and behaviour. The mechanism of this risk is not known and the available data do not exclude the possibility of an increased risk for ethosuximide.
Therefore, patients should be monitored for signs of suicidal ideation and behaviours and appropriate treatment should be considered. Patients (and caregivers of patients) should be advised to seek medical advice should signs of suicidal ideation or behaviour emerge.
Impaired hepatic and renal function
Use with caution in hepatic or renal impairment. Monitor liver/renal function and ethosuximide concentrations.
If ethosuximide is being substituted for another anti-epileptic drug the latter must not be withdrawn abruptly but the replacement made gradually with overlap of the preparations otherwise petit mal may break through.
Ethosuximide should always be withdrawn slowly.
This medicinal product contains sodium ethyl hydroxybenzoate and sodium propyl hydroxybenzoate which may cause allergic reactions (possibly delayed).
This medicinal product contains soya oil. Patients who are allergic to peanut or soya should not use this medicinal product.
This medicinal product contains less than 1 mmol sodium (23 mg) per capsule, that is to say essentially 'sodium-free'
The plasma concentrations of ethosuximide may be reduced by carbamazepine, primidone, phenobarbitone and lamotrigine and increased by isoniazid. No consistent changes in levels of ethosuximide occur when used in combination with phenytoin or sodium valproate. Phenytoin levels however are increased by concomitant ethosuximide.
There is a recognised small increase in the incidence of congenital malformations in children born to mothers receiving anti-convulsants.
For women planning pregnancy or who are already pregnant the risk should be weighed carefully against the benefit of treatment.
Ethosuximide may be excreted into breast milk. Mothers receiving the drug should not breast feed.
Ethosuximide 250 mg Capsules have major influence on the ability to drive and use machines.
Patients should be cautioned that ethosuximide may cause drowsiness and if this occurs should avoid driving or operating machinery.
Blood and lymphatic system disorders
Blood dyscrasias (leucopenia, agranulocytosis, aplastic anaemia and pancytopenia) have been reported, some with fatal outcome. In most cases of leucopenia the blood picture has returned to normal on reduction of dose or discontinuation. In some instances, patients who become leucopenic on other anticonvulsant therapy have been satisfactorily treated with ethosuximide alone. Elevated neutrophil, monocyte and eosinophil counts have also been noted. Patients should be advised to seek immediate medical attention for full blood count tests if symptoms such as fever, sore throat, mouth ulcers, bruising or bleeding develop.
Nervous system disorders
Ethosuximide when used alone in mixed types of epilepsy may increase the frequency of generalised tonic-clonic (grand mal) seizures in some patients.
Other adverse reactions reported
weight loss, diarrhoea, abdominal pain, gum hypertrophy, swelling of the tongue, hiccoughs, irritability, hyperactivity, sleep disturbances, night terrors, inability to concentrate, aggressiveness, paranoid psychosis, increased libido, myopia, and vaginal bleeding.
Mild side effects, common at first but generally transient, include apathy, euphoria, fatigue, drowsiness, dizziness, headache, ataxia, dyskinesia, photophobia, depression, nausea, vomiting, anorexia and gastric upset.
Psychotic states thought to be induced or exacerbated by anticonvulsant therapy have been reported.
Skin and subcutaneous tissue disorders
Rarely cases of skin rash and isolated cases of erythema nodosum have been reported. Lupus-like reactions have occasionally been reported in children given ethosuximide, varying from severe systemic immunological disorders, e.g. the nephrotic syndrome generally with complete recovery on drug withdrawal, to the detection of antinuclear antibodies without clinical features. Stevens-Johnson syndrome has also been reported.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
Where more than 2g has been thought to be ingested gastric lavage may be employed, if the time lapse is less than four hours.
Routine observation of respiration and circulation will indicate the need for supportive measures.
Pharmacotherapeutic group: Succinimide derivates, ATC code: N 03 AD 01
Mechanism of action
The reduction of seizure frequency is thought to be achieved by depression of the motor cortex and elevation of the threshold to convulsive stimuli as seen by the suppression of the characteristic spike and wave EEG pattern.
Ethosuximide gives selective control of absence seizures (petit mal) even when complicated by grand mal. It is also indicated for myoclonic seizures. Compared to other anti-convulsants, ethosuximide is more specific for pure petit mal.
In a double-blind randomized trial of 20 weeks duration in 453 children aged 2.5 to 13 years old with newly diagnosed childhood absence epilepsy, the efficacy, tolerability, and neuropsychlogical effects of ethosuximide, valproic acid and lamotrigine as monotherapy in childhood absence epilepsy were investigated. Those treated with either ethosuximide or valproic acid had higher freedom-from-failure rates (53% and 58%, respectively) than those given lamotrigine (29%; odds ratio with ethosuximide vs. lamotrigine, 2.66; 95% confidence interval [CI], 1.65 to 4.28; odds ratio with valproic acid vs. lamotrigine, 3.34; 95% CI, 2.06 to 5.42; P<0.001 for both comparisons). In both prespecified and post hoc analyses, ethosuximide resulted in fewer attentional effects as compared with valproic acid (at week 16 and week 20, the percentage of subjects with a Confidence Index score of 0.60 or higher in the Conners' Continuous Performance Test was greater in the valproic acid group than in the ethosuximide group (49% vs. 33%; odds ratio, 1.95; 95% CI, 1.12 to 3.41; P=0.03) and the lamotrigine group (49% vs. 24%; odds ratio, 3.04; 95% CI, 1.69 to 5.49; P<0.001).
Ethosuximide is readily absorbed from the gastro-intestinal tract and extensively metabolised in the liver.
It is widely distributed throughout the body but is not significantly bound to plasma proteins, so saliva concentrations may be useful for monitoring.
Peak serum levels occur 1 to 7 hours after single oral dose. Therapeutic levels are between 40 and 100 mcg/ml. It has a long elimination half life: adults 40 - 60 hours; children 30 hours.
It is excreted in the urine mainly in the form of its metabolites.
Sodium ethyl hydroxybenzoate (E 215)
Sodium propyl hydroxybenzoate (E 217)
Miglycol 812 (Fractionated coconut oil)
Store below 30°C away from moisture. Do not refrigerate.
Keep out of sight and reach of children.
Grey polypropylene container with a white low density polyethylene cap containing 56, 112 or 500 capsules.
Not all pack sizes may be marketed.
No special requirements.
Chemidex Pharma Ltd.
T/S Essential Generics
7 Egham Business Village,
Crabtree Road, Egham, Surrey