Multimorbidity and chronic co-prescription networks and potential interactions in adult patients with epilepsy: MorbiNet study

We constructed epilepsy multimorbidity networks to study associations with chronic conditions, and co-prescriptions and drug–disease networks to assess potential interactions. We conducted a population-based study in Catalonia, Spain, with electronic files of 3,135,948 adult patients with multimorbidity, 32,625 of them with epilepsy (active diagnosis any time during 2006–2017). We constructed epilepsy comorbidity networks using logistic regression models from odds ratio estimates adjusted by age, sex, and comorbidities with R software and generated trajectories to study the progression of epilepsy. We constructed drug-disease and co-prescription networks using mixed models with repeated measures adjusting by age, sex, and period with chronic prescription invoiced data. Comorbidity more frequently preceding epilepsy included cerebrovascular accident (OR: 3.59), congenital anomalies (2.18), and multiple sclerosis (1.33); and following epilepsy: dementia (1.91), personality disorder (1.59), alcohol abuse (1.22), and Parkinson (1.21). Mental retardation (13.08), neurological cancer (8.49), benign neoplasm (4.69), infections (3.14), and psychosis (1.58) might precede or not epilepsy. A common progression was to schizophrenia, dementia, and other neurological diseases (mainly cerebral palsy and other degenerative diseases of nervous system). Co-prescription associations with major-moderate potential interactions were 54% for carbamazepine, 61% phenytoin, 53% phenobarbital, and 32% valproate. Major potential interactions were with antipsychotic, anxiolytic, opioid, cardiovascular, and other anti-seizure medications (ASMs). The most frequent comorbidities of epilepsy were congenital, cerebrovascular, and neurological and psychiatric conditions. High comorbidity and co-prescription with potential interactions can increase the complexity of care of patients with epilepsy.