Article Text
Abstract
Introduction Poor-quality artemisinin-containing antimalarials (ACAs), including falsified and substandard formulations, pose serious health concerns in malaria endemic countries. They can harm patients, contribute to the rise in drug resistance and increase the public’s mistrust of health systems. Systematic assessment of drug quality is needed to gain knowledge on the prevalence of the problem, to provide Ministries of Health with evidence on which local regulators can take action.
Methods We used three sampling approaches to purchase 677 ACAs from 278 outlets on Bioko Island, Equatorial Guinea as follows: convenience survey using mystery client (n=16 outlets, 31 samples), full island-wide survey using mystery client (n=174 outlets, 368 samples) and randomised survey using an overt sampling approach (n=88 outlets, 278 samples). The stated active pharmaceutical ingredients (SAPIs) were assessed using high-performance liquid chromatography and confirmed by mass spectrometry at three independent laboratories.
Results Content analysis showed 91.0% of ACAs were of acceptable quality, 1.6% were substandard and 7.4% falsified. No degraded medicines were detected. The prevalence of medicines without the SAPIs was higher for ACAs purchased in the convenience survey compared with the estimates obtained using the full island-wide survey-mystery client and randomised-overt sampling approaches. Comparable results were obtained for full island survey-mystery client and randomised overt.
However, the availability of purchased artesunate monotherapies differed substantially according to the sampling approach used (convenience, 45.2%; full island-wide survey-mystery client, 32.6%; random-overt sampling approach, 21.9%). Of concern is that 37.1% (n=62) of these were falsified.
Conclusion Falsified ACAs were found on Bioko Island, with the prevalence ranging between 6.1% and 16.1%, depending on the sampling method used. These findings underscore the vital need for national authorities to track the scale of ineffective medicines that jeopardise treatment of life-threatening diseases and value of a representative sampling approach to obtain/measure the true prevalence of poor-quality medicines.
- artemisinin based monotherapy
- artemisinin based combination therapy
- artemisinin containing antimalarials
- high-performance liquid chromatography
- mass spectrometry
- drug quality
- degraded medicines
- substandard medicines
- falsified medicines
- outlet surveys
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Footnotes
Handling editor Seye Abimbola
Contributors HK and FM conceived the study. ZH developed methodology to analyse for the degradation products. GG, DH and IM carried out fieldwork and data collections. HK, ELA, ZH, MDG, IS, FMF, PD and MJC performed HPLC-PDA and MS analysis. IM and ELA carried out the statistical analyses of the data. HK wrote the first draft of this manuscript and FM, GG and DH provided all local information. All authors participated in the revision until production of the final draft.
Funding The authors are grateful to the Bill and Melinda Gates Foundation for funding the staff salary and HPLC analysis costs as part of an award to the ACT consortium at the London school of hygiene & tropical medicine. Ministry of Health and Social Welfare, Malabo, Equatorial Guinea (through Medical Care Development International Bioko Island Malaria Control Project) are thanked for funding the sample purchase on Bioko Islands, Equatorial Guinea. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.