Researchers from the Centre of Excellence in Regulatory Science and Innovation in Pharmacogenomics (CERSI-PGx) have published a new prescribing guideline aimed at reducing incidence of serious allergic reactions to common anti-seizure medications.
The new guideline provides advice on HLA genotype testing for carbamazepine, oxcarbazepine and eslicarbazepine. Carbamazepine is a medicine used to treat epilepsy, bipolar disorder and trigeminal neuralgia. It works by calming overactive electrical signals in the brain. Oxcarbazepine and eslicarbazepine are similar to carbamazepine and are mainly used for epilepsy. These drugs can cause serious allergic reactions, especially affecting the skin, which are unpredictable and not dosage dependent.
Research has shown that certain variants in the HLA genes can greatly increase the risk of allergic reactions and therefore carbamazepine, oxcarbazepine and eslicarbazepine should be avoided in people testing positive for these genetic variants.
Rather than duplicating existing international pharmacogenomic guidelines, the UK CERSI-PGx guideline provides a greater clinical focus, offering practical recommendations on:
- Eligibility for testing
- Integration into current clinical pathways
- Variants to test and turnaround times
- Actions based on genotype
- Health economic considerations
- Evidence gaps and future research priorities
CERSI-PGx Lead Professor Sir Munir Pirmohamed commented: "This is the second guideline from CERSI-PGx highlighting the need to genotype for HLA alleles to prevent serious and sometime life-threatening adverse reactions associated with carbamazepine use. As highlighted in the NHS 10-year plan, the NHS intends to roll-out pharmacogenetic testing. Our guideline provides clinicians details on which patients should be tested, what do when a patient has a risk allele, and what alternative medications may be available, taking into account the risk of cross-reactivity with other structurally similar compounds."
UK CERSI-PGx is funded by the MHRA, as part of the UK's network of seven Centres of Excellence in Regulatory Science and Innovation. Collaborators in CERSI-PGx include The University of Manchester, Queen Mary University of London, Bangor University, The Office of Health Economics, The British Pharmacological Society, JS O'Brien Business Solutions, and Alderley Lighthouse Labs.
'HLA genotype testing for carbamazepine, oxcarbazepine and eslicarbazepine: A guideline developed by the UK Centre of Excellence in Regulatory Science and Innovation in Pharmacogenomics (CERSI-PGx)' is published in the British Journal of Clinical Pharmacology.
