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SUMMARY OF PRODUCT CHARACTERISTICS

▼ This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions. See section 4.8 for how to report adverse reactions.

1 NAME OF THE MEDICINAL PRODUCT

Episenta® solution for injection

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Sodium valproate 100mg/ml

3 PHARMACEUTICAL FORM

Solution for injection

4    CLINICAL PARTICULARS

4.1    Therapeutic indications

Episenta® solution for injection may be used for epileptic patients who would normally be maintained on oral sodium valproate but for whom oral therapy is temporarily not possible.

4.2 Posology and method of administration

Female children, female adolescents, women of childbearing potential and pregnant women

Episenta should be initiated and supervised by a specialist experienced in the management of epilepsy. Treatment should only be initiated if other treatments are ineffective or not tolerated (see section 4.4 and 4.6) and the benefit and risk should be carefully reconsidered at regular treatment reviews. Preferably Episenta should be prescribed as monotherapy and at the lowest effective dose, if possible as a prolonged release formulation to avoid high peak plasma concentrations. The daily dose should be divided into at least two single doses.

Dosage requirements vary according to age and body weight and should be adjusted individually to achieve adequate seizure control. Patients already satisfactorily treated with oral sodium valproate may be continued at their current dosage.

Episenta® solution for injection is ready to use by intravenous infusion.

The total daily dose should be divided in three to four single slow intravenous injections or should be given by continuous or repeated infusion.

Monotherapy:

Adults: Dosage should start at 400 - 800mg daily increasing by 150 - 300mg at three day intervals until control is achieved. This is generally within the dosage range of 1000mg to 2000mg per day i.e. 20 - 30mg/kg body weight per daily. Where adequate control is not achieved within this range the dose may be further increased to a maximum of 2500mg per day.

Children: Initial dosage should be 300mg/day increasing until control is achieved. This is usually within the range 20 - 30mg/kg body weight per day. Where adequate control is not achieved within this range, the dose may be increased to 40 mg/kg bodyweight per day but only in patients in whom plasma valproic acid levels can be monitored. Above 40 mg/kg body weight per day clinical chemistry and haematological parameters should be monitored.

Use in elderly: Care should be taken when adjusting dosage in the elderly since the pharmacokinetics of sodium valproate are modified. The volume of distribution is increased in the elderly and because of decreasing binding to serum albumin, the proportion of free drug is increased. This will affect the clinical interpretation of plasma valproic acid levels. Dosage should be determined by seizure control.

In patients with renal insufficiency: It may be necessary to decrease dosage. Dosage should be adjusted according to clinical monitoring of plasma concentration may be misleading.

In patients with renal insufficiency: It may be necessary to decrease dosage. Dosage should be adjusted according to clinical monitoring since monitoring of plasma concentrations may be misleading.

In patients with hepatic insufficiency: Salicylates should not be used concomitantly with sodium valproate since they employ the same metabolic pathway (see section 4.4 Special Warnings and Precautions for Use and 4.8 Undesirable Effects).

Liver dysfunction, including hepatic failure resulting in fatalities, has occurred in patients whose treatment included valproic acid (see section 4.3 Contraindications and 4.4 Special Warnings and Precautions for Use).

Salicylates should not be used in children under 16 years (see aspirin/salicylate product information on Reye’s syndrome). In addition in conjunction with sodium valproate, concomitant use in children under 3 years can increase the risk of liver toxicity (see section 4.4 Special Warnings).

Combined Therapy: When starting Episenta® in patients already on other anticonvulsants these should be tapered slowly. Initiation of Episenta^® therapy should then be gradual, with target dose reached after about two weeks. In certain cases it may be necessary to raise the dose by 5 to 10mg/kg/day when used in combination with liver enzymes inducing drugs such as phenytoin, phenobarbital and carbamazepine. Once known enzyme inducers have been withdrawn it may be possible to maintain seizure control on a reduced dose of Episenta^®.

When barbiturates are being administered concomitantly and particularly if sedation is observed (particularly in children) the dosage of barbiturates should be reduced.

N.B. In children requiring doses higher than 40 mg/kg/day clinical chemistry and haematological parameters should be monitored.

Optimum dosage is mainly determined by seizure control and routine measurement of plasma levels is unnecessary. However, a method for measurement of plasma levels is available and may be helpful where there is poor control or side effects are suspected (see section 5.2 Pharmacokinetic Properties).

Method of administration

Episenta® solution for injection may be given by slow intravenous injection over 3 - 5 minutes or by infusion in 0.9% saline or 5% dextrose.

In accordance with best practice and national guidelines, a filter device with a pore size of not more than 5 pm is recommended when drawing up from an ampoule before the administration of IV products, including Episenta® solution for injection.

Episenta® solution for injection should not be administered via the same intravenous line with other drugs.

The intravenous administration of Episenta® solution for injection should be replaced by oral therapy as soon as practicable.

Close monitoring of plasma levels and - if necessary - dosage adjustments have to be performed during the change-over to a parenteral therapy, during parenteral therapy and during the switch back to oral therapy, in particular in such patients receiving higher doses of valproate or in patients receiving drugs potentially influencing the metabolism of valproate.

For instructions on preparation and dilution of Episenta® solution for injection before administration see section 6.6 Special Precautions for Disposal.

4.3    Contraindications

Active liver disease.

Personal or family history of severe hepatic dysfunction, especially drug related.

Porphyria.

Hypersensitivity to valproate or any of the excipients.

Valproate is contraindicated in patients known to have mitochondrial disorders caused by mutations in the nuclear gene encoding the mitochondrial enzyme polymerase y (POLG), e.g. Alpers-Huttenlocher Syndrome, and in children under two years of age who are suspected of having a POLG-related disorder (see section 4.4).

4.4    Special warnings and precautions for use

Suicidal ideation and behaviour have been reported in patients treated with antiepileptic agents in several indications. A meta-analysis of randomised placebo controlled trials of antiepileptic 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 sodium valproate.

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.

Although there is no specific evidence of sudden recurrence of underlying symptoms following withdrawal of valproate, discontinuation should normally only be done under the supervision of a specialist in a gradual manner. This is due to the possibility of sudden alterations in plasma concentrations giving rise to a recurrence of symptoms.

The concomitant use of sodium valproate and carbapenem is not recommended (see section 4.5 Interaction with other medicinal products and other forms of interaction).

Hepatic dysfunction :

Conditions of occurrence:

Severe liver damage, including hepatic failure sometimes resulting in fatalities, has been very rarely reported. Experience in epilepsy has indicated that patients most at risk, especially in cases of multiple anticonvulsants therapy, are infants and in particular young children under the age of 3 and those with severe seizure disorders, organic brain disease, and (or) congenital metabolic or degenerative disease associated with mental retardation. After the age of 3, the incidence of occurrence is significantly reduced and progressively decreases with age. The concomitant use of salicylates should be avoided in children under 3 due to the risk liver toxicity. Additionally, salicylates should not be used in children under 16 years of age (see aspirin/salicylate product information on Reye’s syndrome).

Monotherapy is recommended in children under the age of 3 years when prescribing Episenta®, but the potential benefit of Episenta® should be weighed against the risk of liver damage or pancreatitis in such patients prior to initiation of therapy.

In most cases, such liver damage occurred during the first 6 months of therapy, the period of maximum risk being 2 - 12 weeks.

Suggestive signs:

Clinical symptoms are essential for early diagnosis. In particular the following conditions, which may precede jaundice, should be taken into consideration, especially in patients at risk (see above: Conditions of occurrence):

-    non-specific symptoms, usually of sudden onset, such as asthenia, malaise, anorexia, lethargy, oedema and drowsiness, which are sometimes associated with repeated vomiting and abdominal pain.

-    in patients with epilepsy, recurrence of seizures

These are an indication for immediate withdrawal of the drug.

Patients (or their carers), should be instructed to report immediately any such signs to a physician should they occur. Investigations including clinical examination and biological assessment of liver function should be undertaken immediately.

Detection:

Liver function should be measured before and then periodically monitored during the first 6 months of therapy, especially in those who seem at risk, and those with a prior history of liver disease. Amongst usual investigations, tests which reflect protein synthesis, particularly prothrombin rate, are most relevant. Confirmation of an abnormally low prothrombin rate, particularly in association with other biological abnormalities (significant decreases in fibrinogen and coagulation factors; increased bilirubin level and raised transaminases) require cessation of Episenta® therapy.

As a matter of precaution and in case they are taken concomitantly salicylates should also be discontinued since they employ the same metabolic pathway.

As with most antiepileptic drugs, increased liver enzymes are common, particularly at the beginning of therapy; they are also transient.

More extensive biological investigations (including prothrombin rate) are recommended in these patients; a reduction in dosage may be considered when appropriate and tests should be repeated as necessary.

Pancreatitis:

Pancreatitis, which may be severe and result in fatalities, has been very rarely reported. Patients experiencing nausea, vomiting or acute abdominal pain should have a prompt medical evaluation (including measurement of serum amylase).

Young children are at particular risk; this risk decreases with increasing age. Severe seizures and severe neurological impairment with combination anticonvulsant therapy may be risk factors. Hepatic failure with pancreatitis increases the risk of fatal outcome. In case of pancreatitis, Episenta® should be discontinued.

Haematological:

Blood tests (blood cell count, including platelet count, bleeding time and coagulation tests) are recommended prior to initiation of therapy or before surgery, and in case of spontaneous bruising or bleeding. (see section 4.8 Undesirable effects).

Renal insufficiency:

In patients with renal insufficiency, it may be necessary to decrease dosage. As monitoring of plasma concentrations may be misleading, dosage should be adjusted according to clinical monitoring (see sections 4.2 Posology and method of administration and 5.2 Pharmacokinetic properties).

Systemic lupus erythematosus:

Although immune disorders have only rarely been noted during the use of sodium valproate, the potential benefit of Episenta® should be weighed against its potential risk in patients with systemic lupus erythematosus (see section 4.8 Undesirable effects).

Hyperammonaemia:

When urea cycle enzymatic deficiency is suspected, metabolic investigations should be performed prior to treatment because of risk of hyperammonaemia with sodium valproate.

Weight gain:

Sodium valproate very commonly causes weight gain, which may be marked and progressive. Patients should be warned of the risk of weight gain at the initiation of therapy and appropriate strategies should be adopted to minimise it (see section 4.8 Undesirable effects)

Female children/Female adolescents/Women of childbearing potential/Pregnancy:

Episenta should not be used in female children, in female adolescents, in women of childbearing potential and pregnant women unless alternative treatments are ineffective or not tolerated because of its high teratogenic potential and risk of developmental disorders in infants exposed in utero to valproate. The benefit and risk should be carefully reconsidered at regular treatment reviews, at puberty and urgently when a woman of childbearing potential treated with Episenta plans a pregnancy or if she becomes pregnant.

Women of childbearing potential must use effective contraception during treatment and be informed of the risks associated with the use of Episenta during pregnancy (see section 4.6).

The prescriber must ensure that the patient is provided with comprehensive information on the risks alongside relevant materials, such as a patient information booklet, to support her understanding of the risks.

In particular the prescriber must ensure the patient understands:

•    The nature and the magnitude of the risks of exposure during pregnancy, in particular the teratogenic risks and the risks of developmental disorders.

•    The need to use effective contraception.

•    The need for regular review of treatment.

•    The need to rapidly consult her physician if she is thinking of becoming pregnant or there is a possibility of pregnancy.

In women planning to become pregnant all efforts should be made to switch to appropriate alternative treatment prior to conception, if possible (see section 4.6).

Valproate therapy should only be continued after a reassessment of the benefits and risks of the treatment with valproate for the patient by a physician experienced in the management of epilepsy.

Diabetic Patients:

Sodium valproate is eliminated mainly through the kidneys, partly in the form of ketone bodies: this may give false positive in the urine testing of possible diabetics.

Patients with known or suspected mitochondrial disease

Valproate may trigger or worsen clinical signs of underlying mitochondrial diseases caused by mutations of mitochondrial DNA as well as the nuclear encoded POLG gene. In particular, valproate-induced acute liver failure and liver-related deaths have been reported at a higher rate in patients with hereditary neurometabolic syndromes caused by mutations in the gene for the mitochondrial enzyme polymerase y (POLG), e.g. Alpers-Huttenlocher Syndrome.

POLG-related disorders should be suspected in patients with a family history or suggestive symptoms of a POLG-related disorder, including but not limited to unexplained encephalopathy, refractory epilepsy (focal, myoclonic), status epilepticus at presentation, developmental delays, psychomotor regression, axonal sensorimotor neuropathy, myopathy, cerebellar ataxia, ophthalmoplegia, or complicated migraine with occipital aura. POLG mutation testing should be performed in accordance with current clinical practice for the diagnostic evaluation of such disorders (see section 4.3).

4.5 Interaction with other medicinal products and other forms of interaction

4.5.1 Effects of Episenta® on other drugs

Like many other drugs, Episenta® may potentiate the effect of other psychotropics, such as antipsychotics, monoamine oxidase inhibitors, antidepressants and benzodiazepines. Therefore, clinical monitoring and the dosage of other psychotropics should be adjusted when appropriate. In particular, a clinical study has suggested that adding olanzapine to valproate or lithium therapy may significantly increase the risk of certain adverse events associated with olanzapine e.g. neutropenia, tremor, dry mouth, increased appetite and weight gain, speech disorder and somnolence.

Sodium valproate increases phenobarbital plasma concentrations and sedation may occur, particularly in children. Clinical monitoring is recommended throughout the first 15 days of combined treatment with an immediate reduction of phenobarbital doses if sedation occurs and determination of phenobarbital levels when appropriate.

Sodium valproate increases primidone plasma levels causing an exacerbation of side effects, e.g. sedation; these signs cease with long term treatment.. Clinical monitoring is recommended especially when initiating combined therapy with dosage adjustment as necessary.

Phenytoin total plasma levels are decreased by sodium valproate acid; the free form of phenytoin is increased leading to possible overdosage symptoms. Therefore, clinical monitoring is recommended with the free form of phenytoin being measured.

The toxic effects of carbamazepine may be potentiated by sodium valproate requiring clinical monitoring and dosage adjustment particularly at initiation of combined therapy.

Sodium valproate may reduce lamotrigine metabolism and increase its mean half-life. The dosage of lamotrigine should be decreased as necessary. The risk of rash is increased in combined therapy with lamotrigine.

Sodium valproate may raise zidovudine plasma concentrations leading to increased zidovudine toxicity.

The anticoagulant effect of warfarin and other coumarin anticoagulants may be increased following displacement from the plasma protein binding site by valproate. The prothombin time should be closely monitored.

Co-administration of temozolomide and sodium valproate may cause a small decrease in the clearance of temozolomide that is not thought to be clinically relevant.

_®

4.5.2    Effects of other drugs on Episenta

Antiepileptics with enzyme inducing effects e.g. phenytoin, phenobarbital, carbamazepine, decrease valproate plasma levels. Plasma levels should be monitored and dosage adjusted accordingly. On the other hand, combination of felbamate and sodium valproate may increase valproic acid plasma concentration. Episenta^® dosage should be monitored.

Mefloquine and chloroquine increases valproate metabolism and therefore epileptic seizures may occur in combined therapy. The dosage of sodium valproate may need adjustment.

Free valproate levels may be increased in the case of concomitant use with highly protein bound agents e.g. acetylsalicylic acid. Valproate plasma levels may also be increased when used concomitantly with cimetidine or erythromycin as a result of reduced hepatic metabolism.

Decreases in blood levels of valproic acid have been reported when it is coadministered with carbapenem agents resulting in a 60 - 100% decrease in valproic acid levels in about two days. Due to rapid onset and the extent of the decrease, coadministration of carbapenem agents in patients stablised on valproic acid is not considered to be manageable and therefore should be avoided (see section 4.4 Special warnings and precautions for use).

Colestyramine may decrease the absorption of valproate.

Rifampicin may decrease the valproate blood levels resulting in a lack of therapeutic effect. Therefore, valproate dosage adjustment may be necessary when it is coadministered with rifampicin.

4.5.3 Other interaction

Sodium valproate usually has no enzyme-inducing effect; as a consequence, Episenta® does not reduce efficacy of oestroprogestative agents in women receiving hormonal contraception, including the oral contraceptive pill.

Caution is advised when using Episenta® in combination with newer antiepileptics whose pharmacodynamics may not be well established Concomitant administration of valproate and topiramate has been associated with encephalopathy and/or hyperammonaemia. In patients taking these two drugs, careful monitoring of signs and symptoms is advised in particularly at-risk patients such as those with pre-existing encephalopathy.

4.6 Fertility, pregnancy and lactation

Episenta should not be used in female children, in female adolescents, in women of childbearing potential and in pregnant women unless other treatments are ineffective or not tolerated. Women of childbearing potential have to use effective contraception during treatment. In women planning to become pregnant all efforts should be made to switch to appropriate alternative treatment prior to conception, if possible.

Pregnancy Exposure Risk related to valproate

Both valproate monotherapy and valproate polytherapy are associated with abnormal pregnancy outcomes. Available data suggest that antiepileptic polytherapy including valproate is associated with a greater risk of congenital malformations than valproate monotherapy.

Congenital malformations

Data derived from a meta-analysis (including registries and cohort studies) has shown that 10.73% of children of epileptic women exposed to valproate monotherapy during pregnancy suffer from congenital malformations (95%

CI: 8.16 -13.29). This is a greater risk of major malformations than for the general population, for whom the risk is about 2-3%. The risk is dose dependent but a threshold dose below which no risk exists cannot be established.

Available data show an increased incidence of minor and major malformations. The most common types of malformations include neural tube defects, facial dysmorphism, cleft lip and palate, craniostenosis, cardiac, renal and urogenital defects, limb defects (including bilateral aplasia of the radius), and multiple anomalies involving various body systems.

Developmental disorders

Data have shown that exposure to valproate in utero can have adverse effects on mental and physical development of the exposed children. The risk seems to be dose-dependent but a threshold dose below which no risk exists, cannot be established based on available data. The exact gestational period of risk for these effects is uncertain and the possibility of a risk throughout the entire pregnancy cannot be excluded.

Studies in preschool children exposed in utero to valproate show that up to 3040% experience delays in their early development such as talking and walking later, lower intellectual abilities, poor language skills (speaking and understanding) and memory problems.

Intelligence quotient (IQ) measured in school aged children (age 6) with a history of valproate exposure in utero was on average 7-10 points lower than those children exposed to other antiepileptics. Although the role of confounding factors cannot be excluded, there is evidence in children exposed to valproate that the risk of intellectual impairment may be independent from maternal IQ.

There are limited data on the long term outcomes.

Available data show that children exposed to valproate in utero are at increased risk of autistic spectrum disorder (approximately three-fold) and childhood autism (approximately five-fold) compared with the general study population.

Limited data suggests that children exposed to valproate in utero may be more likely to develop symptoms of attention deficit/hyperactivity disorder (ADHD).

Female children, female adolescents and women of childbearing potential (see above and section 4.4)

If a Woman wants to plan a Pregnancy

•    During pregnancy, maternal tonic clonic seizures and status epilepticus with hypoxia may carry a particular risk of death for mother and the unborn child.

•    In women planning to become pregnant or who are pregnant, valproate therapy should be reassessed.

•    In women planning to become pregnant all efforts should be made to switch to appropriate alternative treatment prior to conception, if possible.

Valproate therapy should not be discontinued without a reassessment of the benefits and risks of the treatment with valproate for the patient by a physician experienced in the management of epilepsy. If based on a careful evaluation of the risks and the benefits valproate treatment is continued during the pregnancy, it is recommended to:

•    Use the lowest effective dose and divide the daily dose valproate into several small doses to be taken throughout the day. The use of a prolonged release formulation may be preferable to other treatment formulations in order to avoid high peak plasma concentrations.

•    Folate supplementation before the pregnancy may decrease the risk of neural tube defects common to all pregnancies. However the available evidence does not suggest it prevents the birth defects or malformations due to valproate exposure.

•    To institute specialized prenatal monitoring in order to detect the possible occurrence of neural tube defects or other malformations.

Risk in the neonate

•    Cases of hemorrhagic syndrome have been reported very rarely in neonates whose mothers have taken valproate during pregnancy. This hemorrhagic syndrome is related to thrombocytopenia, hypofibrinogenemia and/or to a decrease in other coagulation factors. Afibrinogenemia has also been reported and may be fatal. However, this syndrome must be distinguished from the decrease of the vitamin-K factors induced by phenobarbital and enzymatic inducers. Therefore, platelet count, fibrinogen plasma level, coagulation tests and coagulation factors should be investigated in neonates.

•    Cases of hypoglycaemia have been reported in neonates whose mothers have taken valproate during the third trimester of their pregnancy.

•    Cases of hypothyroidism have been reported in neonates whose mothers have taken valproate during pregnancy.

•    Withdrawal syndrome (such as, in particular, agitation, irritability, hyper-excitability, jitteriness, hyperkinesia, tonicity disorders, tremor, convulsions and feeding disorders) may occur in neonates whose mothers have taken valproate during the last trimester of their pregnancy.

Breastfeeding

Valproate is excreted in human milk with a concentration ranging from 1 % to 10 % of maternal serum levels. Hematological disorders have been shown in breastfed newborns/infants of treated women (see section 4.8).

A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Episenta therapy taking into account the benefit of breast feeding for the child and the benefit of therapy for the woman.

Fertility

Amenorrhoea, polycystic ovaries and increased testosterone levels have been reported in women using valproate (see section 4.8). Valproate administration may also impair fertility in men (see section 4.8). Case reports indicate that fertility dysfunctions are reversible after treatment discontinuation.

4.7 Effects on ability to drive and use machines

Use of Episenta® may provide seizure control such that the patient may be eligible to hold a driving licence.

At the start of treatment with sodium valproate, at higher dosages or with a combination of other centrally acting drugs, reaction time may be altered to an extent that affects the ability to drive or to operate machinery, irrespective of the effect on the primary disease being treated. Patients should be warned of the risk of transient drowsiness. This is especially the case when taken during anticonvulsant polytherapy, concomitant use of benzodiazepines or in combination with alcohol.

4.8 Undesirable effects

Hepato-biliary disorders:

Rare cases of hepatic dysfunction (see section 4.4 Special warnings and precautions for use). Severe liver damage, including hepatic failure sometimes resulting in fatalities, has been reported (see sections 4.2 (Posology and method of administration,

4.3 Contraindications and 4.4 Special warnings and precautions for use). Increased liver enzymes are common, particularly early in treatment, and may be transient (see section 4.4 Special warnings and precautions for use ).

Gastro-intestinal disorders: (nausea, gastralgia, diarrhoea)

Frequently occur at the start of the treatment, but they usually disappear after a few days without discontinuing treatment. These problems can usually be overcome by taking Episenta^® with or after food.

Very rare cases of pancreatitis, sometimes fatal, have been reported (see section 4.4 Special warnings and precautions for use).

Nervous system disorders:

Sedation has been reported occasionally, usually when in combination with other anticonvulsants. In monotherapy it occurred early in treatment on rare occasions and is usually transient. Rare cases of lethargy and confusion occasionally progressing to stupor, sometimes with associated hallucinations or convulsions have been reported. Encephalopathy and coma have very rarely been observed. These cases have often been associated with a too high starting dose or a too rapid dose escalation or concomitant use of other anticonvulsants, notably phenobarbital or topiramate. They have usually been reversible on withdrawal of treatment or reduction of dosage.

Very rare cases of reversible extrapyramidal symptoms including parkinsonism, or reversible dementia associated with reversible cerebral atrophy have been reported. Dose related ataxia and fine postural tremor have occasionally been reported.

An increase in alertness may occur, this is generally beneficial but occasionally aggression, hyperactivity and behavioural deterioration have been reported.

Metabolism and nutrition disorders:

Cases of isolated and moderate hyperammonaemia without change in liver function tests may occur frequently, are usually transient and should not cause treatment discontinuation. However, they may present clinically as vomiting, ataxia, and increasing clouding of consciousness. Should these symptoms occur Episenta® should be discontinued. Very rare cases of hyponatraemia have been reported. Hyperammonaemia associated with neurological symptoms have also been reported (see section 4.4 Special warnings and precautions for use). In such cases further investigation should be considered.

Obesity (rare)

Blood and lymphatic system disorders:

Frequent occurrence of thrombocytopenia, rare cases of anaemia, leucopenia or panocytopenia. The blood picture returned to normal when the drug was discontinued.

Bone marrow failure, including red cell aplasia.

Agranulocytosis.

Isolated reduction in blood fibrinogen and/or an increase in prothrombin time have been reported, usually without associated clinical signs and particularly with high doses (sodium valproate has an inhibitory effect on the second phase of platelet aggregation). Spontaneous bruising or bleeding is an indication of withdrawal of medication pending investigations (see section 4.6 Pregnancy and lactation).

Skin and subcutaneous tissue disorders:

Rash rarely occurs with sodium valproate. In very rare cases, toxic epidermal necrolysis, Stevens-Johnson syndrome and erythema multiforme have been reported. Transient hair loss, which may sometimes be dose-related, has often been reported. Regrowth normally begins within 6 months, although the hair may become more curly than previously. Hirsutism and acne have been very rarely reported.

Nail and nail bed disorders (common)

Musculoskeletal and connective tissue disorders

There have been reports of decreased bone mineral density, osteopenia, osteoporosis and fractures in patients on long-term therapy with sodium valproate. The mechanism by which sodium valproate affects bone metabolism has not been identified.

Reproductive system and breast disorders:

Amenorrhoea and irregular periods have been reported. Very rarely gynaecomastia has occurred.

Vascular disorders:

The occurrence of vasculitis has occasionally been reported.

Ear disorders:

Hearing loss, either reversible or irreversible has been reported rarely; however a cause and effect relationship has not been established.

Renal and urinary disorders:

There have been isolated reports of reversible Fanconi’s syndrome (a defect in proximal renal tubular function giving rise to glycosuria, amino aciduria, phospaturia, and uricosuria) associated with sodium valproate therapy, but the mode of action is as yet unclear. Very rare cases of enuresis have been reported.

Immune system disorders:

Angiodema, Drug Rash with Eosinophilia Systemic Symptoms (DRESS) syndrome and allergic reactions (ranging from rash to hypersensitivity reactions) have been reported.

Congenital, familial and genetic disorders

Congenital malformations and developmental disorders (see section 4.4 and section 4.6).

General disorders:

Very rare cases of non-severe peripheral oedema have been reported.

Increase in weight may also occur. Weight gain being a risk factor for polycystic ovary syndrome, it should be carefully monitored (see section 4.4 Special warnings and precautions for use).

When using Episenta® intravenously, transient nausea or dizziness may occur. 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 national reporting system (see details below).

Yellow Card Scheme

Website: www.mhra.gov.uk/yellowcard

4.9 Overdose

Cases of accidental and deliberate overdosage with oral therapy have been reported. At plasma concentrations of up to 5 to 6 times the maximum therapeutic levels, there are unlikely to be any symptoms other than nausea, vomiting and dizziness. In massive overdose, 10 to 20 times the maximum therapeutic levels, there may be serious CNS depression or coma with muscular hypotonia, hyporeflexia, miosis, impaired respiratory function, metabolic acidosis. A favourable outcome is usual, however some deaths have occurred following massive overdose.

The symptoms may however be variable and seizures have been reported in the presence of very high plasma levels. Cases of intracranial hypertension related to cerebral oedema have been reported. A number of deaths have occurred following large overdoses. Hospital management of overdose includes induced vomiting, gastric lavage, assisted ventilation and other supportive measures. Haemodialysis and haemoperfusion have been used successfully. Intravenous naloxone has also been used sometimes in association with activated charcoal given orally.

5    PHARMACOLOGICAL PROPERTIES

5.1    Pharmacodynamic properties

ATC no: N03AG01

The mode of action of valproic acid in epilepsy is not fully understood but may involve an elevation of gamma-amino butyric acid levels in the brain.

In certain in-vitro studies, it was reported that sodium valproate could stimulate HIV replication but studies on peripheral blood mononuclear cells from HIV-infected subjects show that sodium valproate does not have a mitogen-like effect on inducing HIV replication. Indeed, the effect of sodium valproate on HIV replication ex-vivo is highly variable, modest in quantity, appears to be unrelated to the dose and has not been documented in man.

5.2 Pharmacokinetic properties

Per definition, with intravenous injection the bioavailability amounts to 100. The half-life is 8 - 20 h in most patients but can in exceptional cases be considerable lower. It is usually shorter in children. In infants under 2 months the half-life can be prolonged up to 60 hours. In patients with severe renal insufficiency it may be necessary to alter dosage in accordance with free serum valproic acid levels.

Steady-state concentration is normally achieved after treatment in 3 - 5 days. A satisfactory effect is most often achieved at 40 - 100mg/litre (278 - 694 micromol/litre), but the patient’s overall situation must be considered. The reported range may depend on time of sampling and presence of co-medication. An increased incidence of adverse effects may occur with plasma levels above the effective therapeutic range.

The pharmacological (or therapeutic) effects of Episenta® may not be clearly correlated with the total or free (unbound) plasma valproic acid levels. The CFS concentration is up to 10% of the plasma concentration. The percentage of free (unbound) drug is usually between 6 and 15% of the total plasma levels. Sodium valproate is metabolised to a great extent and is excreted in the urine as conjugated metabolites. Sodium valproate crosses the placental barrier and concentrations in foetal plasma are comparable to those in the mother.

Valproic acid passes into breast milk but is not likely to influence the child when therapeutic doses are used.

5.3 Preclinical safety data

Acute toxicity

Depending on the species of the animal and mode of administration the LD₅₀ is between 0.5 - 1.5g/kg body weight. The symptoms observed included, for example, ataxia, sedation, hypothermia, catelapsy, co-ordination disorders and vomiting.

Chronic toxicity

Testicular atrophy, degeneration of the vas deferens and insufficient spermatogenesis as well as lung and prostate gland changes have been observed in chronic toxicity studies at dosages of more than 250 mg/kg in rats and 90 mg/kg in the dog. In rats, at 200 mg/kg p.o., morphological hepatocytes changes were seen. At 750 mg/kg i.p., functional liver disorders and, among other things, hyperammonaemia, occurred.

Carcinogenic and mutagenic potential

Carcinogenic studies have been conducted in the rat and mouse. At very high doses, increased subcutaneous fibrosarcoma was observed in male rats.

Studies of mutagenic potential have shown no mutagenic effect.

Reproduction toxicology

Valproic acid has been found to be teratogenic in mice, rats, hamsters, monkeys and rabbits. The effects occur primarily as skeletal (palatal cleft, costal and vertebral fusion) and renal malformations, in mice also as encephalocele and malformation of the neural tube. Malformations have also been observed in neurulation studies in chicken embryo in vitro.

6 PHARMACEUTICAL PARTICULARS

6.1 List of excipients

Disodium edetate Water for injections

6.2 Incompatibilities

Episenta® solution for injection should not be administered via the same intravenous line with other drugs.

6.3 Shelf life

Shelf life of the medicinal product as packaged for sale: 3 years.

Shelf life after dilution or reconstitution according to the directions: Chemical and physical in-use stability has been demonstrated for 3 days at 20 - 22°C. From a microbiological point of view, the product should be used immediately after opening. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and would normally be not longer than 24 hours at 2 to 8°C, unless dilution has taken place in controlled and validated aseptic conditions.

6.4 Special precautions for storage

Do not freeze.

6.5 Nature and contents of container

Glass ampoule containing 3 ml or 10 ml solution for injection.

Special precautions for disposal