Ethosuximide Essential Generics 250 mg/5 ml Syrup: Clinical Particulars

1. Name of the medicinal product

Emeside 250 mg/5 ml Syrup

Ethosuximide Essential Generics 250 mg/5 ml Syrup

2. Qualitative and quantitative composition

Each 5 ml contains 250 mg ethosuximide

Excipient with known effect:

Each 5 ml of this medicine contains 3.06 g sucrose.

For the full list of excipients, see section 6.1.

3. Pharmaceutical form

Syrup

A dark-red-brown liquid with a flavour of blackcurrant.

4. Clinical particulars

4.1 Therapeutic indications

Ethosuximide gives selective control of absence seizures (petit mal) even when complicated by grand mal.

It is also indicated for myoclonic seizures.

4.2 Posology and method of administration

Posology

Adults, the elderly and children over 6 years

Start with a small dose – 500 mg daily with increments of 250 mg 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

Begin with a daily dose of 250 mg (5ml) and increase the dose gradually by small increments every few days until control is achieved. The optimal dose in most children is 20 mg/kg/day. The maximum dose should be 1000 mg.

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.

Older children and adults will normally take ethosuximide in capsule form.

Currently available clinical data regarding the use of ethosuximide in the paediatric population are described in section 5.1.

Method of administration

For oral use.

4.3 Contraindications

- Hypersensitivity to the active substance, succinimides or to any of the excipients listed in section 6.1.

- Porphyrias.

4.4 Special warnings and precautions for use

Suicidal behaviour

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.

Withdrawal

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.

Excipients

This medicine contains 3.05 g sucrose per 5 ml, equivalent to 610 mg per ml and between 0.16 g and 0.22 g of other sugars per 5 ml. This should be taken into account in patients with diabetes mellitus. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine. May be harmful to teeth.

This medicine contains less than 1 mmol sodium (23 mg) per 5 ml syrup, that is to say essentially 'sodium-free'.

4.5 Interaction with other medicinal products and other forms of interaction

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.

4.6 Fertility, pregnancy and lactation

Pregnancy

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.

Breastfeeding

Ethosuximide may be excreted into breast milk. Mothers receiving the drug should not breast feed.

4.7 Effects on ability to drive and use machines

Ethosuximide Syrup 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.

4.8 Undesirable effects

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 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.

4.9 Overdose

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.

5. Pharmacological properties

5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Succinimide derivatives, ATC code: N03AD01

Pharmacodynamic effects

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.

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.

Paediatric population

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 neuropsychological 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-failures 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 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 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).

5.2 Pharmacokinetic properties

Absorption

Ethosuximide is readily absorbed from the gastro-intestinal tract and extensively metabolised in the liver.

Distribution

It is widely distributed throughout the body but is not significantly bound to plasma proteins so saliva concentrations may be useful for monitoring.

Biotransformation

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.

Elimination

It is excreted in the urine mainly in the form of its metabolites.

5.3 Preclinical safety data

None stated

6. Pharmaceutical particulars

6.1 List of excipients

Sucrose

Saccharin sodium

Water

Blackcurrant juice

6.2 Incompatibilities

Not applicable.

6.3 Shelf life

5 years.

6.4 Special precautions for storage

Store below 30°C. Do not refrigerate or freeze.

6.5 Nature and contents of container

200 ml amber glass bottle with tamper evident child resistant polypropylene/polyethylene white cap.

6.6 Special precautions for disposal and other handling

No special requirements.

7. Marketing authorisation holder

Essential Pharma Ltd.,

7 Egham Business Village,

Crabtree Road, Egham, Surrey

TW20 8RB

United Kingdom

8. Marketing authorisation number

PL 41871/0006

9. Date of first authorisation/renewal of the authorisation

13/03/2007

10. Date of revision of the text

27/08/2020