Long-term outcome of phenobarbital treatment for epilepsy in rural China: A prospective cohort study

Summary Purpose: To evaluate the long-term outcome of phenobarbital treatment for convulsive epilepsy in rural China, and to explore factors associated with overall seizure outcomes. Methods: We carried out follow-up assessments of people who took part in an epilepsy community management program conducted in rural counties of six provinces in China. People with convulsive epilepsy who were previously untreated (or on irregular treatment) were commenced on regular treatment with phenobarbital. Information was collected using a standardized questionnaire by face-to-face interviews of the individuals (and their families where necessary). Information collected included treatment status, medication change, seizure frequency, and mortality. Key Findings: Among the 2,455 people who participated in the original program, outcomes were successfully ascertained during the follow-up assessment in 1986. Among them, 206 had died. Information on treatment response was obtained in 1,780 (56% male; mean age 33.9 years, range 3-84; mean duration of follow-up 6.4 years). Among them, 939 (53%) were still taking phenobarbital. The most common reasons for stopping phenobarbital were seizure freedom or substantial seizure reduction, socioeconomic reasons, and personal preference. Four hundred fifty-three individuals (25%) became seizure-free for at least 1 year while taking phenobarbital, 88% of whom did so at daily doses of 120 mg or below. Four hundred six (23%) reported adverse events, which led to withdrawal of phenobarbital in <1%. The most common adverse effects were malaise/somnolence (7.4%), dizziness (3%), and lethargy (2.6%). At the follow-up assessment, 688 (39%) individuals had been seizure free for at least the previous year. People with persistent seizures had significantly longer duration of epilepsy and higher number of seizures in the 12 months before treatment. People who were taking AED treatment irregularly at recruitment were less likely to become seizure-free. Significance: We observed long-term benefits of regular treatment with phenobarbital for convulsive epilepsy in rural China. One hundred years after the discovery of its antiepileptic effect, phenobarbital is still playing an important role in the management of epilepsy.