valproic acid at a glance
Medicine class
Anticonvulsant, also called an anti-epileptic.
Licensed role
Treatment of generalised, partial and other epilepsy; eligibility restrictions depend on age, sex and reproductive circumstances.
Capsule administration
Swallow gastro-resistant capsules whole. They can be taken with or without food; food may reduce stomach upset.
What is valproic acid used for?
Uses depend on the particular valproate product and its licence.
The selected Convulex capsule is licensed for generalised, partial and other epilepsy, subject to current reproductive-risk restrictions.
Valproic acid is also used in specialist practice for bipolar disorder and migraine prevention, but these are not indications in this Convulex SmPC and licensing differs between products.
How does valproic acid work?
Valproic acid dampens excessive electrical signalling associated with seizures. Its action is not fully understood, but it is thought to strengthen the inhibitory effect of GABA in the brain.
valproic acid preparations and strengths
Capsule
Route: Oral
Strengths: 150 mg, 300 mg, 500 mg
How to take valproic acid
Follow the dispensing-label directions and use the same product consistently unless a clinician or pharmacist manages a change.
Swallow gastro-resistant capsules whole with water; do not chew them.
They may be taken with or without food, but use the same approach each time.
Taking capsules with or after food may lessen nausea or stomach discomfort.
Do not stop treatment suddenly without specialist advice, because seizures may recur or worsen.
valproic acid side effects
Common or expected effects
- Nausea, vomiting, stomach pain or diarrhoea
- Tremor, headache, sleepiness or dizziness
- Weight gain
- Temporary hair thinning or changes in hair texture or colour
- Menstrual changes
Get urgent medical advice
- Liver injury: jaundice, dark urine, profound tiredness, appetite loss or repeated vomiting
- Pancreatitis: severe persistent abdominal pain, often with nausea or vomiting
- Blood or clotting disorders: unexplained bruising, bleeding or marked pallor
- Hyperammonaemic encephalopathy: vomiting, poor coordination, increasing drowsiness or confusion
- Severe skin reaction or angioedema: blistering or peeling rash, facial swelling or breathing difficulty
- New or worsening seizures, suicidal thoughts or major behavioural change
valproic acid in pregnancy
Valproate exposure in pregnancy carries a high risk of congenital malformations and lasting neurodevelopmental problems. It must not be used by women or girls able to become pregnant unless strict Pregnancy Prevention Programme conditions are met. Pregnancy use is restricted to exceptional circumstances where specialists document that no effective or tolerated alternative exists. Contact a clinician urgently if pregnancy is suspected or planned, but do not stop treatment without specialist review. Men taking valproate should also discuss reproductive risks, contraception and family planning with their clinician.
valproic acid while breastfeeding
Valproate enters breast milk in small amounts and may sometimes be used cautiously while breastfeeding a healthy, full-term infant after individual assessment. Monitor the baby for unusual sleepiness, poor feeding or weight gain, jaundice, vomiting, diarrhoea, bruising or bleeding. Seek professional advice if these occur. Specialist advice is particularly important for premature or unwell infants or when several medicines are used.
valproic acid interactions
Valproic acid has clinically important interactions. Check prescribed, non-prescription and herbal products with a pharmacist or prescriber.
Carbapenem antibiotics, including meropenem and imipenem
They can rapidly and substantially reduce valproate concentrations, risking loss of seizure control; concurrent use should generally be avoided.
Lamotrigine
Valproate slows lamotrigine metabolism and can increase exposure and the risk of serious rash, requiring specialist management.
Warfarin and other coumarin anticoagulants
Valproate may increase anticoagulant effect and bleeding risk; closer coagulation monitoring may be needed.
Common questions about valproic acid
Answers are fully visible for fast scanning and source review.
What is valproic acid used for?
The selected Convulex capsule is licensed for generalised, partial and other epilepsy, with additional restrictions for some patients because of reproductive risks.
Can valproic acid capsules be opened or chewed?
Gastro-resistant capsules should be swallowed whole and not chewed.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.