Safety and Tolerability Profile of Artemisinin-Based Antimalarial Combination Therapy in Adult Patients in Benin City, Nigeria

Abstract

The WHO in 2001 advocated artemisinin- based antimalarial combination therapy (ACT), which was adopted by Nigeria in 2005. The objective of this study was to characterize the safety and tolerability profile of the ACTs in adult patients with uncomplicated malaria. A descriptive longitudinal study was conducted in the General Practice Clinic–of the University of Benin Teaching Hospital (UBTH) and the Central Hospital, Benin City, South-South Nigeria, between October 2009 and March 2010. Adult patients (e”18years) with a diagnosis of uncomplicated malaria and treated with ACTs were recruited for the study. The safety and tolerability profile of ACTs amongst the treated patients were assessed after 9 days of follow up via telephone calls. Adverse Events were classified using the WHO causalityassessment. Five hundred patients were enrolled for this study – Artemether/Lumefantrine (AL) (179), Artesunate/Mefloquine (AM) (149), Artesunate/Amodiauine (AA) (134) Artesunate/Sulphadoxine/Pyrimethamine (ASP) (22), Dihydroartemisinin/ Piperaquine (DP) (16). The mean age of the respondents was 32.6years (range 18-68yrs). One hundred and eighty-eight (37.6%) of the total number of patients followed up reported at least one Adverse Events: 61% in the AA, 60% in the AM, 58% in the AL, 31% in DP, 4 of 19 (21.1%) in ASP. AA treatment was associated with a significant higher risk of gastrointestinal symptoms, dizziness and pruritus than AL and AM (p<0.05). Those treated with AM had a higher incidence of generalized weakness. Ten of the respondents discontinued therapy due to Adverse events experienced: AM (4), AA (4), AL (1), DP (1). Severe AEs were observed in two of these pateints that were given AA and AM respectively. The safety and tolerability of artemetherlumefantrine (AL) and dihydroartemisinin piperaquine (DP) was confirmed in this study. The other recommended ACTs (artesunate-amodiaquine (AA) and artesunate mefloquine (AM) although safe, were less well tolerated and this may affect patients’ adherence with its attendant consequences.

Keywords: Artemisinin-based Combination therapy, Adverse Events, Malaria