ORIGINAL RESEARCH ARTICLE Safety Profile of Artemether-Lumefantrine: A Cohort Event Monitoring Study in Public Health Facilities in Tanzania Alambo K. Mssusa 1 • Adam M. Fimbo 2 • Alex F. Nkayamba 1 • Henry F. Irunde 3 • Hiiti B. Sillo 2 • Danstan H. Shewiyo 4 • Geraldine Hill 5 • Omary M. Minzi 6 Ó Springer International Publishing Switzerland 2016 Abstract Background and Objective Artemisinin combination therapies such as artemether-lumefantrine (AL) are effec- tive for first-line treatment of uncomplicated acute Plas- modium falciparum malaria. However, the safety profile of AL in large populations has not been fully assessed. The objective of this study was to establish the safety of AL in public health facilities in Tanzania using the Cohort Event Monitoring (CEM) method. Methodology Patients who presented to public health facilities in four regions of Tanzania who were prescribed AL were enrolled in a CEM study, a prospective, obser- vational cohort study to establish a profile of adverse events (AEs) for the medicine when used in routine clinical practice. Pre- and post-treatment forms were used to record baseline information and new health events before and 7 days after treatment. Results A total of 8040 patients were enrolled in the study, of whom 6147 were included in the analysis. Following treatment initiation, a total of 530 AEs were reported in 6 % (383) of the patients. The most frequent post-treatment AEs were in alimentary system (42 %), including vomiting, nausea, diarrhoea, abdominal pain and anorexia, followed by AEs in the neurological system (25 %). Causality assess- ment of the events showed that 51.9 % (275/530) were possibly related to AL. There was a significant difference in the frequency of AEs by age-group with an increase in the number of AEs as age increased (P \ 0.001). There was no statistically significant difference in the frequency of the events between males and females (P = 0.504). The AE profile was consistent with the AEs reported in the product information and in other studies; no new adverse drug reactions were identified. The majority of the reported AEs were the same as the symptoms of malaria and therefore indistinguishable from the underlying disease. Conclusions The safety profile of AL for treatment of malaria continues to be favourable. CEM as a pharma- covigilance tool has proven to provide reliable safety data in a short period. Key Points The artemether-lumefantrine safety profile continues to be favourable. The Cohort Event-Monitoring method is a reliable pharmacovigilance tool. Electronic supplementary material The online version of this article (doi:10.1007/s40261-016-0385-z) contains supplementary material, which is available to authorized users. & Alambo K. Mssusa alambopharm@yahoo.com 1 Department of Clinical Trials Control and Pharmacovigilance, Tanzania Food and Drugs Authority, P.O. Box 77150, Dar Es Salaam, Tanzania 2 Directorate of Medicines and Complementary Products, Tanzania Food and Drugs Authority, P.O. Box 77150, Dar Es Salaam, Tanzania 3 Pharmaceutical Services Unit, Ministry of Health and Social Welfare, P.O. Box 9083, Dar Es Salaam, Tanzania 4 Directorate of Laboratory Services, Tanzania Food and Drugs Authority, P.O. Box 77150, Dar Es Salaam, Tanzania 5 Uppsala Monitoring Centre, WHO Collaborating Centre for International Drug Monitoring, Box 1051, 75140 Uppsala, Sweden 6 Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, P.O. Box 65013, Dar Es Salaam, Tanzania Clin Drug Investig DOI 10.1007/s40261-016-0385-z