Before starting

Required

• Baseline
  • Body mass index
  • Clotting screening · including bleeding time and coagulation tests
  • Full blood count
  • Liver function tests
  • Platelet count
  • Pregnancy test · see advice on valproate use by women and girls

Specialist initiation only

Only specialists can initiate or recommend initiation in adults and children.

Continued until stable

Required

• Liver function tests

Ongoing once stable

Required

• At 6 months, then annually
  • Body mass index
  • Full blood count
  • Liver function tests

Before surgery or following spontaneous bleeding or bruising

• Once
  • Clotting screening · including bleeding time and coagulation tests
  • Full blood count

Abnormal results

Hepatic effects

Raised liver enzymes are usually transient but patients should be assessed clinically and FBC (including platelets) and liver function (including prothrombin time and coagulation tests) monitored until return to normal. Discontinue if abnormal liver function.

Haematological effects

Discontinue if abnormally prolonged prothrombin time or blood dyscrasias.

Pancreatitis

In case of pancreatitis, valproate should be discontinued.

Notes

Advice to patients

Advise patients and carers to be aware of the signs of:

• Blood or liver disorders; advise them to seek immediate medical attention if symptoms develop
• Pancreatitis; advise them to seek immediate medical attention if symptoms such as abdominal pain, nausea and vomiting develop

Brand prescribing

Valproate is classified as a category 2 drug. Hence, for epilepsy only, clinical judgement is required when switching between branded original and generic products.

Conception

There is a significant risk of birth defects and developmental disorders in children born to women who take valproate during pregnancy.

The MHRA advice provides full information on the risks and issues.

Healthcare professionals can also refer to:

• NICE – Summary of guidance and safety advice
• Royal College of General Practitioners and Association of British Neurologists and Royal College of Physicians – Clinical guidance to support healthcare professionals involved in the care of women on valproate.
• British Paediatric Neurology Association (BPNA) and the Royal College of Paediatrics and Child Health (RCPCH) – Joint guidance to provide recommendations about the use of valproate in female patients under 18 years of age.

Bibliography

• Aventis Pharma Limited. Summary of Product Characteristics – Epilim 200 mg Gastro-resistant tablets. Last revised 04/2020 [cited 30/07/2020]
• David Taylor, Thomas R.E. Barnes and Allan H. Young. The Maudsley. Prescribing Guidelines in Psychiatry – 13th Edition 2018 [citied 30/07/2020]
• Medicines and Healthcare products Regulatory Agency. Antiepileptic drugs: updated advice on switching between different manufacturers’ products. Drug Safety Update volume 11, issue 4; November 2017: 5 [cited June 2020]
• National Institute for Health and Care Excellence (NICE). Epilepsies: diagnosis and management [CG137]. Jan 2012 [updated May 2021; cited 30/07/2020]
• Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press [cited 30/08/2020]
• National Institute for Health and Care Excellence (NICE). Bipolar disorder: assessment and management [CG185]. Sep 2014 [updated Feb 2020; cited 30/07/2020]
• NICE Clinical Knowledge Summaries (CKS). Epilepsy. Updated Jul 2019 [cited 30/07/2020]
• Medicines and Healthcare products Regulatory Agency (MHRA). Valproate use by women and girls. Guidance published March 2018 [cited 30/07/2020].