Mapping the availability, price, and affordability of antiepileptic drugs in 46 countries

Purpose: In low- and middle-income countries (LMICs), a large proportion of people with epilepsy do not receive treatment. An analysis of the availability, price, and affordability of antiepileptic drugs (AEDs) was conducted to evaluate whether these factors contribute to the treatment gap. Methods: Data for five AEDs (phenytoin, carbamazepine, valproic acid, phenobarbital, and diazepam) were obtained from facility-based surveys conducted in 46 countries using the World Health Organization/Health Action International (WHO/HAI) methodology. Outcome measures were percentage availability, ratios of local prices to international reference prices, and number of days' wages needed by the lowest-paid unskilled government worker to purchase treatment. Prices were adjusted for inflation/deflation and purchasing power parity. Key Findings: The average availability of generic AEDs in the public sector was <50% for all medicines except diazepam injection. Private sector availability of generic oral AEDs ranged from 42.2% for phenytoin to 69.6% for phenobarbital. Public sector patient prices for generic carbamazepine and phenytoin were 4.95 and 17.50 times higher than international reference prices, respectively, whereas private sector patient prices were 11.27 and 24.77 times higher, respectively. For both medicines, originator brand prices were about 30 times higher. The highest prices were observed in the lowest income countries. The lowest-paid government worker would need wages from 1-2.6 days' to purchase a month's supply of phenytoin, whereas carbamazepine would cost 2.7-16.2 days' wages. Despite its widespread use in LMICs, WHO/HAI survey data for phenobarbital was only available from a small number of countries. Significance: In LMICs, availability and affordability of AEDs are poor and may be acting as a barrier to accessing treatment for epilepsy. Ensuring a consistent supply of AEDs at an affordable price should be a priority.