Pharmacoepidemiology and prevalence of epileptic seizures in Southeastern Nigeria

Abstract

The aim of this study was to establish an estimated number of people living with epilepsy in southeastern Nigeria, to determine the prevalence and the utilization pattern of antiepileptic drugs (AEDs). A cross sectional, observational survey was used in the study. Multi-stage random sampling technique was used to select four centers in Anambra and Enugu states in southeastern Nigeria. The selected centers were Nnamdi Azikiwe University Teaching Hospital, Nnewi (NAUTH) and Neuropsychiatric Hospital, Nawfia (NHN) both in Anambra State, while University of Nigeria Teaching Hospital, Ituku-Ozalla (UNTH) and Federal Neuropsychiatric Hospital, Enugu (FNH) are located in Enugu State. Parameters evaluated from patients’ folders were gender (G), age of onset (AO), type of seizure (TS) and the probable cause of seizure (CS). The AEDs utilization pattern was evaluated and the estimation of the point prevalence was also made. A total of 365 epileptic cases of different types were investigated, with 62.7 and 37.3 percent occuring in males and females, respectively. The 13-29 age of onset (AO) showed the highest occurrence with 40.1 percent. The tonic clonic type of generalized epilepsy was highest in occurrence with 62.74% while the least was absence seizure with 2.28%. Among these, some were due to idiopathic origin while most of the cases were due to secondary or symptomatic causes. The results showed that carbamazepine, sodium valproate, diazepam and phenobarbital were the most highly prescribed drugs with 58.2, 26.1, 9.8 and 7.6 percent usages, respectively. The point prevalence for epilepsy based on this study was estimated to be 5.0 per 100,000 for southeastern Nigeria. Epilepsy in Southeastern Nigeria has a low prevalence of 5.0 per 100,000 with highest rate of onset occurring among 13-29 age range while generalized tonic clonic (GTC) seizure type occurred most and carbamazepine, a conventional AED, was the most highly prescribed.

Keywords: epilepsy, pharmacoepidemiology, prevalence, southeastern Nigeria, carbamazepine