Susan Jamison was 16 when she had a full-blown seizure at school. It had never happened before, though for weeks she’d been getting bad headaches. A neurologist diagnosed epilepsy and prescribed her a high dose of sodium valproate — four 500mg pills a day. The drug was considered effective and safe for preventing seizures. It worked for Susan, who is now 53: she has taken it ever since. Sodium valproate is prescribed in the UK under various brand names — Susan takes one called Epilim — and works by blocking nerve activity in the brain involved in seizures. For some patients, it is the only …
