valproate semisodium at a glance
Medicine class
Mood stabiliser acting mainly within the central nervous system.
Licensed role
Treatment of bipolar mania when no other effective or tolerated treatment is available.
Tablet type
Gastro-resistant tablets that must be swallowed whole, not crushed or chewed.
Reproductive safeguards
Strict prescribing and pregnancy-prevention measures apply, particularly to people younger than 55 years.
What is valproate semisodium used for?
Selected products are licensed for:
Manic episodes associated with bipolar disorder, where no other effective or tolerated treatment is available.
Possible continuation after a manic episode in people who responded during acute mania.
How does valproate semisodium work?
It acts mainly in the brain and is thought to strengthen the inhibitory action of GABA, helping to reduce excessive neuronal activity associated with mania.
valproate semisodium preparations and strengths
Gastro-resistant tablet
Route: Oral
Strengths: 250 mg, 500 mg
Tablet
Route: Oral
Strengths: 250 mg, 500 mg
How to take valproate semisodium
Follow the prescription label and specialist’s instructions. Do not stop treatment suddenly unless directed by the specialist.
Swallow gastro-resistant tablets whole with water; do not crush or chew them.
They may be taken with or without food; taking them consistently may help. Food may reduce stomach upset.
Check the pack carefully because valproate products have different licensed uses and formulations.
valproate semisodium side effects
Common or expected effects
- Nausea, vomiting, stomach discomfort or diarrhoea
- Tremor, headache, sleepiness or tiredness
- Weight gain
- Temporary hair thinning or changes in hair texture
- Changes in menstrual periods
- Mouth soreness or swollen gums
Get urgent medical advice
- Liver injury, including jaundice, dark urine, repeated vomiting, profound tiredness or abdominal pain
- Pancreatitis, including severe or persistent abdominal pain, nausea and vomiting
- Blood disorders, including unexplained bruising, bleeding, fever or sore throat
- Hyperammonaemic encephalopathy, including vomiting, unsteadiness and increasing confusion or reduced consciousness
- Severe allergic or blistering skin reactions
- New distressing thoughts, self-harm or suicidal thoughts
valproate semisodium in pregnancy
Valproate semisodium for bipolar disorder is contraindicated during pregnancy because exposure can cause major congenital malformations and permanent developmental problems. Women and girls able to become pregnant must meet Pregnancy Prevention Programme conditions when exceptional treatment is considered. Anyone planning pregnancy or who may be pregnant should contact their prescriber urgently and must not stop treatment without specialist advice.
valproate semisodium while breastfeeding
Valproate enters breast milk in small amounts. Breastfeeding may sometimes be possible after individual specialist assessment. Seek advice if the baby develops poor feeding, unusual sleepiness, vomiting, diarrhoea, bruising or jaundice.
valproate semisodium interactions
Tell the prescriber or pharmacist about all medicines, supplements and herbal products. Important interactions include:
Carbapenem antibiotics
They can rapidly and substantially lower valproate concentrations, risking loss of effect; combined use should generally be avoided.
Lamotrigine
Valproate increases lamotrigine exposure and toxicity risk, including serious skin reactions.
Warfarin and other coumarin anticoagulants
Valproate may increase anticoagulant effects and bleeding risk.
Common questions about valproate semisodium
Answers are fully visible for fast scanning and source review.
What is valproate semisodium used for?
Selected products are licensed for manic episodes in bipolar disorder when no other effective or tolerated treatment is available. Continuation may be considered after a response during acute mania.
Is it the same as sodium valproate?
No. Valproate semisodium is a stable compound containing sodium valproate and valproic acid. Valproate products can have different formulations and licensed uses, so should not be exchanged without professional confirmation.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.