Valproic acid = VPA = Sodium valproate oral

Therapeutic action

Antiseizure (antiepileptic), mood stabilizer.

Indications

• Epilepsy: generalised tonic-clonic seizures, focal (partial) seizures, and absence seizures.
• Prevention of recurrence of bipolar disorder.

Forms and strengths

• 200 mg and 500 mg enteric-coated tablets.
• 200 mg/5 ml oral solution to be administered using a measuring device.

Dose

Start with a low dose then increase gradually based on the patient's response and tolerance.

VPA must not be used in pregnancy or in women and girls of childbearing age. The risk of foetal harm is higher than with other antiseizure medications.

Due to the numerous and potentially severe adverse effects of VPA, patients should be kept under close surveillance.

Duration

As long as required. Do not stop treatment abruptly, even if changing treatment to another medication.

Contra-indications, adverse effects, precautions

• Do not administer to women and girls of childbearing age unless treatment is necessary and there is no alternative, with a negative pregnancy test and effective contraception required.
• Do not administer to children under 2 years, to patients with pancreatitis, hepatic disease, or history of hepatic disease.
• Reduce dosage in patients with renal impairment.
• May cause drowsiness, extrapyramidal symptoms, behavioural disturbances, confusional state, insomnia, weight gain, menstrual irregularities, gastrointestinal disturbances, vitamin D deficiency, osteoporosis, thrombocytopenia, and rarely pancreatitis, hepatic disorders, prolonged bleeding time, hypersensitivity reactions, or hyperammonemic encephalopathy.
• Early symptoms such as fever, rash, mouth ulcers, and bleeding require immediate medical attention.
• If possible, perform at least full blood count, liver enzymes, and serum sodium levels at baseline then regularly during treatment, and check prothrombin time before surgical procedures.
• Avoid or monitor combination with mefloquine, carbapenems, tricyclic antidepressants, rifampicin, protease inhibitors, other antiseizure medications, acetylsalicylic acid, erythromycin, isoniazid, alcohol-containing drugs, benzodiazepines, opioid analgesics, antipsychotics, first-generation antihistamines, antidepressants, and other antiseizure medications.
• Avoid alcohol during treatment.
• Pregnancy: do not use because of the risk of neural tube defects, major malformations, and neurodevelopmental disorders.
• In case of pregnancy during treatment, change to a safer drug such as levetiracetam if possible. If VPA is the only option, use the lowest effective dose and divide doses over the day.
• Administer folic acid high dose, 5 mg daily, during the first trimester starting as early as possible.
• Breast-feeding: administer with caution and monitor the child for hepatotoxicity and bleeding.
• Take with meals.