Valex 400 IV Injection

Broad-spectrum antiepileptic and mood stabiliser for:

• All types of epilepsy: generalised (absence, myoclonic, tonic-clonic) and focal seizures
• Manic episodes of bipolar disorder (when lithium is unsuitable)
• Migraine prevention (adults, specialist)

Epilepsy (adults): start 600 mg daily in 2 divided doses (or once daily with modified release); increase by 150–300 mg every 3 days to usually 1–2 g daily (20–30 mg/kg/day; maximum 2.5 g).

Children: up to 20 kg: 20 mg/kg/day; over 20 kg: start 400 mg daily, increase to 20–30 mg/kg/day in divided doses (up to 35 mg/kg/day).

Bipolar mania: 750 mg daily in divided doses initially, adjusted to response (usually 1–2 g daily).

• Take with or after food; swallow enteric-coated/controlled-release tablets whole.
• Do not stop suddenly — risk of seizures.

• Pregnancy and women/girls who could become pregnant, unless a pregnancy prevention programme is in place (except in epilepsy where no alternative works)
• Active liver disease, or family history of severe liver dysfunction (especially drug-related)
• Mitochondrial disorders (e.g. POLG mutations — Alpers' syndrome)
• Porphyria, urea cycle disorders
• Allergy to valproate

Common: nausea, stomach pain, diarrhoea, weight gain, tremor, hair thinning or curling, drowsiness, low platelets, raised liver enzymes, menstrual changes.

Less common: confusion, unsteadiness, swelling, raised ammonia, low sodium, rash.

Rare but serious: liver failure (especially children under 3 on multiple antiepileptics — vomiting, drowsiness, jaundice, loss of seizure control), pancreatitis (severe abdominal pain), bleeding disorders, encephalopathy, severe skin reactions, suicidal thoughts, polycystic ovaries.

In pregnancy: high risk of birth defects (about 1 in 10) and developmental/learning problems (up to 3–4 in 10).

• Women and girls of child-bearing potential: must use effective contraception and be reviewed annually by a specialist; do not stop suddenly if pregnancy occurs — see the doctor urgently.
• Liver function and blood counts before starting and during the first 6 months.
• Report vomiting, abdominal pain, unusual tiredness, jaundice, bruising or bleeding.
• Watch for mood changes and suicidal thoughts.

Avoid in pregnancy — causes major birth defects (spina bifida, heart, facial defects) and lowers IQ/increases autism risk. Use only if no other treatment works, after specialist counselling. Take high-dose folic acid if used. Compatible with breastfeeding (monitor the baby for jaundice and bruising).

• Carbapenems (meropenem, imipenem) — rapidly lower valproate levels; avoid
• Lamotrigine (valproate doubles its level — lamotrigine dose must be reduced; rash risk)
• Phenytoin, carbamazepine, phenobarbital, rifampicin, oestrogen contraceptives (alter levels)
• Aspirin (raises free valproate; bleeding)
• Warfarin (monitor INR)
• Topiramate (raised ammonia)
• Alcohol, sedatives

Drowsiness, coma, breathing depression, low blood pressure, small pupils, metabolic acidosis, high ammonia. Emergency care.

Store below 30°C, dry (tablets absorb moisture — keep in original pack).