Availability and Costs of Antiepileptic Drugs and Quality of Phenobarbital in Vientiane Municipality, Lao PDR

Abstract

Purpose: In developing countries, availability and quality of drugs are critical factors for effective management and control of epilepsy. This study investigated the availability and costs of antiepileptic drugs (AEDs), and the quality of phenobarbital in Vientiane Municipality, Lao PDR. Methods: In March 2004, we enrolled all pharmacies (categories I and II) of four central districts of Vientiane eligible to sell AEDs. Two hundred and eight pharmacies of category III (75.1% of all registered pharmacies) were excluded as the sale of AEDs was not authorized. All pharmacists were interviewed with a standard questionnaire. Whenever phenobarbital was available, a sample was purchased and assayed by liquid chromatography. Phenobarbital was defined as being of correct quality if the active substance average content corresponded to ±15% of the indicated amount. Results: 66 pharmacies were enrolled (13 and 45 of categories I and II, respectively, and 8 hospital pharmacies). Six generics of AEDs were found (phenobarbital, phenytoin, valproic acid, clonazepam, carbamazepine, diazepam) and all pharmacies sold at least 1 AED. The 2 most widely available drugs were diazepam (5 mg) and phenobarbital (100 mg), present in 87.9 and 53.0% of the pharmacies, respectively. All 34 phenobarbital samples examined showed a correct concentration of the active compound. However, the concentration of phenobarbital 100 mg tablets produced in Lao PDR (mean concentration 94.7 mg) was significantly lower (p = 0.005) than the imported equivalent (mean concentration 99.7 mg). The direct drug costs of a yearly treatment with phenobarbital were estimated to be at least 25.2 USD. Conclusions:A variety of AEDs are present. Their availability, particularly of phenobarbital, is restricted to higher-category pharmacies and within those it is rather limited. To meet the costs of AEDs in this setting is a major challenge for people with epilepsy. However, the quality of the available phenobarbital was rather satisfactory.