Brands, costs and registration status of antimalarial drugs in the Kenyan retail sector

A retail audit of mosquito control products in Busia County, western Kenya

Background

Approximately 70% of Kenya’s population is at risk for malaria. The core vector control methods in Kenya are insecticide-treated mosquito nets (ITNs) and indoor residual spraying, with supplementary larval source management. In 2015, 21% of ITNs were accessed through the private retail sector. Despite the private sector role in supplying mosquito control products (MCPs), there is little evidence on the availability, sales trends, and consumer preferences for MCPs other than ITNs. This study, a component of a larger research programme focused on evaluating a spatial repellent intervention class for mosquito-borne disease control, addressed this evidence gap on the role of the private sector in supplying MCPs.

Methods

A cross-sectional survey was deployed in a range of retail outlets in Busia County to characterize MCP availability, sales trends, and distribution channels. The questionnaire included 32 closed-ended and four open-ended questions with short answer responses. Descriptive analysis of frequency counts and percentages was carried out to glean insights about commercially available MCPs and the weighted average rank was used to determine consumer preferences for MCPs. Open-ended data was analysed thematically.

Results

Retail outlets that stocked MCPs commonly stocked mosquito coils (73.0%), topical repellents (38.1%), aerosol insecticide sprays (23.8%) and ITNs (14.3%). Overall, retailers reported the profits from selling MCPs were adequate and they overwhelmingly planned to continue stocking the products. Of respondents who stocked MCPs, 96.8% responded that sales increased during long rains and 36.5% that sales also surged during short rains. ITNs and baby-size nets were often delivered by the wholesaler. Retailers of aerosol sprays, mosquito coils, and topical repellents either collected stock from the wholesaler or products were delivered to them. Other commercially available MCPs included insecticide incense sticks, electric mosquito strikers, insecticide soaps, electrically heated insecticide mats, and electric insecticide emanators, indicating a well-established market.

Conclusions

The wide range of MCPs in local retail outlets within the study area suggests the need and demand for mosquito control tools, in addition to ITNs, that are affordable, easy to use and effective. The presence of a wide range of MCPs, is a promising sign for the introduction of a spatial repellent intervention class of products that meets consumer needs and preferences.

Examining the Quality of Medicines at Kenyan Healthcare Facilities: A Validation of an Alternative Post-Market Surveillance Model That Uses Standardized Patients

BACKGROUND

Promoting access to medicines requires concurrent efforts to strengthen quality assurance for sustained impact. Although problems of substandard and falsified medicines have been documented in low- and middle-income countries, reliable information on quality is rarely available.

OBJECTIVE

The aim of this study was to validate an alternative post-market surveillance model to complement existing models.

METHODS

The study used standardized patients or mystery clients (people recruited from the local community and trained to pose as real patients) to collect medicine samples after presenting a pre-specified condition. The patients presented four standardized conditions to 42 blinded facilities in Nairobi, Kenya, resulting in 166 patient-clinician interactions and dispensing of 300 medicines at facilities or nearby retail pharmacies. The medicine samples obtained thus resemble those that would be given to real patients.

RESULTS

Sixty samples were selected from the 300, and sent for analysis at the Kenya National Quality Control Laboratory. Of these, ten (17%) did not comply with monograph specifications (three ibuprofen, two cetirizine, two amoxicillin/clavulanic acid combinations, and one each for prednisone, salbutamol and zinc). Five of the ten samples that failed had been inappropriately prescribed to patients who had presented symptoms of unstable angina. There was no association between medicine quality and ownership, size or location of the facilities.

CONCLUSION

The study shows that the standardized patient model can provide insights into multiple dimensions of care, thus helping to link primary care encounters with medicine quality. Furthermore, it makes it possible to obtain medicines from blinded sellers, thus minimizing the risk of obtaining biased samples.

Public health interventions to protect against falsified medicines: a systematic review of international, national and local policies

BACKGROUND

Falsified medicines are deliberately fraudulent drugs that pose a direct risk to patient health and undermine healthcare systems, causing global morbidity and mortality.

OBJECTIVE

To produce an overview of anti-falsifying public health interventions deployed at international, national and local scales in low and middle income countries (LMIC).

DATA SOURCES

We conducted a systematic search of the PubMed, Web of Science, Embase and Cochrane Central Register of Controlled Trials databases for healthcare or pharmaceutical policies relevant to reducing the burden of falsified medicines in LMIC.

RESULTS

Our initial search identified 660 unique studies, of which 203 met title/abstract inclusion criteria and were categorised according to their primary focus: international; national; local pharmacy; internet pharmacy; drug analysis tools. Eighty-four were included in the qualitative synthesis, along with 108 articles and website links retrieved through secondary searches.

DISCUSSION

On the international stage, we discuss the need for accessible pharmacovigilance (PV) global reporting systems, international leadership and funding incorporating multiple stakeholders (healthcare, pharmaceutical, law enforcement) and multilateral trade agreements that emphasise public health. On the national level, we explore the importance of establishing adequate medicine regulatory authorities and PV capacity, with drug screening along the supply chain. This requires interdepartmental coordination, drug certification and criminal justice legislation and enforcement that recognise the severity of medicine falsification. Local healthcare professionals can receive training on medicine quality assessments, drug registration and pharmacological testing equipment. Finally, we discuss novel technologies for drug analysis which allow rapid identification of fake medicines in low-resource settings. Innovative point-of-purchase systems like mobile phone verification allow consumers to check the authenticity of their medicines.

CONCLUSIONS

Combining anti-falsifying strategies targeting different levels of the pharmaceutical supply chain provides multiple barriers of protection from falsified medicines. This requires the political will to drive policy implementation; otherwise, people around the world remain at risk.

The role of folate in malaria - implications for home fortification programmes among children aged 6-59 months

Folic acid and iron supplementation has historically been recommended as the preferred anaemia control strategy among preschoolers in sub-Saharan Africa and other resource-poor settings, but home fortification of complementary foods with multiple micronutrient powders (MNPs) can now be considered the preferred approach. The World Health Organization endorses home fortification with MNPs containing at least iron, vitamin A and zinc to control childhood anaemia, and calls for concomitant malaria control strategies in malaria endemic regions. Among other micronutrients, current MNP formulations generally include 88 μg folic acid (corresponding to 100% of the Recommended Nutrient Intake). The risks and benefits of providing supplemental folic acid at these levels are unclear. The limited data available indicate that folate deficiency may not be a major public health problem among children living in sub-Saharan Africa and supplemental folic acid may therefore not have any benefits. Furthermore, supraphysiological, and possibly even physiological, folic acid dosages may favour Plasmodium falciparum growth, inhibit parasite clearance of sulphadoxine-pyrimethamine (SP)-treated malaria and increase subsequent recrudescence. Even though programmatic options to limit prophylactic SP use or to promote the use of insecticide treated bed nets may render the use of folic acid safer, programmatic barriers to these approaches are likely to persist. Research is needed to characterise the prevalence of folate deficiency among young children worldwide and to design safe MNP and other types of fortification approaches in sub-Sahara Africa. In parallel, updated global guidance is needed for MNP programmes in these regions.

Chloroquine sensitivity: diminished prevalence of chloroquine-resistant gene marker pfcrt-76 13 years after cessation of chloroquine use in Msambweni, Kenya

Background

Plasmodium falciparum resistance to chloroquine (CQ) denied healthcare providers access to a cheap and effective anti-malarial drug. Resistance has been proven to be due to point mutations on the parasite’s pfcrt gene, particularly on codon 76, resulting in an amino acid change from lysine to threonine. This study sought to determine the prevalence of the pfcrt K76T mutation 13 years after CQ cessation in Msambweni, Kenya.

Methods

Finger-prick whole blood was collected on 3MM Whatman^® filter paper from 99 falciparum malaria patients. Parasite DNA was extracted via the Chelex method from individual blood spots and used as template in nested PCR amplification of pfcrt. Apo1 restriction enzyme was used to digest the amplified DNA to identify the samples as wild type or sensitive at codon 76. Prevalence figures of the mutant pfcrt 76T gene were calculated by dividing the number of samples bearing the mutant gene with the total number of samples multiplied by 100 %. Chi square tests were used to test the significance of the findings against previous prevalence figures.

Results

Out of 99 clinical samples collected in 2013, prevalence of the mutant pfcrt 76T gene stood at 41 %.

Conclusion

The results indicate a significant [χ² test, P ≤ 0.05 (2006 vs 2013)] reversal to sensitivity by the P. falciparum population in the study site compared to the situation reported in 2006 at the same study site. This could primarily be driven by diminished use of CQ in the study area in line with the official policy. Studies to establish prevalence of the pfcrt 76T gene could be expanded countrywide to establish the CQ sensitivity status and predict a date when CQ may be re-introduced as part of malaria chemotherapy.

The policy-practice gap: describing discordances between regulation on paper and real-life practices among specialized drug shops in Kenya

BACKGROUND

Specialized drug shops (SDSs) are popular in Sub-Saharan Africa because they provide convenient access to medicines. There is increasing interest in how policymakers can work with them, but little knowledge on how their operation relates to regulatory frameworks. This study sought to describe characteristics and predictors of regulatory practices among SDSs in Kenya.

METHODS

The regulatory framework governing the Kenya pharmaceutical sector was mapped, and a list of regulations selected for inclusion in a survey questionnaire. An SDS census was conducted, and survey data collected from 213 SDSs from two districts in Western Kenya.

RESULTS

The majority of SDSs did not comply with regulations, with only 12% having a refrigerator and 22% having a separate dispensing area for instance. Additionally, less than half had at least one staff with pharmacy qualification (46%), with less than a third of all interviewed operators knowing the name of the law governing pharmacy.Regulatory infringement was more common among SDSs in rural locations; those that did not have staff with pharmacy qualifications; and those whose operator did not know the name of the pharmacy law. Compliance was not significantly associated with the frequency of inspections, with over 80% of both rural and urban SDSs reporting an inspection in the past year.

CONCLUSION

While compliance was low overall, it was particularly poor among SDSs operating in rural locations, and those that did not have staff with pharmacy qualification. This suggested the need for policy to introduce levels of practice in recognition of the variations in resource availability. Under such a system, rural SDSs operating in low-resource setting, and selling a limited range of medicines, may be exempted from certain regulatory requirements, as long as their scope of practice is limited to certain essential services only. Future research should also explore why regulatory compliance is poor despite regular inspections.

Methods for implementing a medicine outlet survey: lessons from the anti-malarial market

BACKGROUND

In recent years an increasing number of public investments and policy changes have been made to improve the availability, affordability and quality of medicines available to consumers in developing countries, including anti-malarials. It is important to monitor the extent to which these interventions are successful in achieving their aims using quantitative data on the supply side of the market. There are a number of challenges related to studying supply, including outlet sampling, gaining provider cooperation and collecting accurate data on medicines. This paper provides guidance on key steps to address these issues when conducting a medicine outlet survey in a developing country context. While the basic principles of good survey design and implementation are important for all surveys, there are a set of specific issues that should be considered when conducting a medicine outlet survey.

METHODS

This paper draws on the authors' experience of designing and implementing outlet surveys, including the lessons learnt from ACTwatch outlet surveys on anti-malarial retail supply, and other key studies in the field. Key lessons and points of debate are distilled around the following areas: selecting a sample of outlets; techniques for collecting and analysing data on medicine availability, price and sales volumes; and methods for ensuring high quality data in general.

RESULTS AND CONCLUSIONS

The authors first consider the inclusion criteria for outlets, contrasting comprehensive versus more focused approaches. Methods for developing a reliable sampling frame of outlets are then presented, including use of existing lists, key informants and an outlet census. Specific issues in the collection of data on medicine prices and sales volumes are discussed; and approaches for generating comparable price and sales volume data across products using the adult equivalent treatment dose (AETD) are explored. The paper concludes with advice on practical considerations, including questionnaire design, field worker training, and data collection. Survey materials developed by ACTwatch for investigating anti-malarial markets in sub-Saharan Africa and Asia provide a helpful resource for future studies in this area.

Establishing pharmacovigilance programs in resource-limited settings: the example of treating malaria

The unprecedented levels of political, technical and financial support for improved malaria control, and particularly for changes in the malaria treatment policy, have heralded a renewed appreciation of the role of pharmacovigilance, its relationship with other areas of public health and the development of novel approaches to addressing the pharmacovigilance priorities in malaria-endemic countries. In order to become a valuable public health activity in these resource-limited settings, pharmacovigilance needs to be viewed within its broadest definition of detecting, understanding and preventing adverse drug reactions and drug-related problems. Pharmacovigilance in resource-limited settings provides an opportunity to identify and address health system failures that significantly impact on patient morbidity and mortality, particularly those that are drug related. Countries need to establish a national strategy that identifies realistic and relevant objectives that meet the most pressing pharmacovigilance needs, taking into consideration the conditions under which these systems are likely to develop.

Examining characteristics, knowledge and regulatory practices of specialized drug shops in Sub-Saharan Africa: a systematic review of the literature

BACKGROUND

Specialized drug shops such as pharmacies and drug shops are increasingly becoming important sources of treatment. However, knowledge on their regulatory performance is scarce. We set out to systematically review literature on the characteristics, knowledge and practices of specialized drug shops in Sub-Saharan Africa.

METHODS

We searched PubMed, EMBASE, WEB of Science, CAB Abstracts, PsycINFO and websites for organizations that support medicine policies and usage. We also conducted open searches using Google Scholar, and searched manually through references of retrieved articles. Our search included studies of all designs that described characteristics, knowledge and practices of specialized drug shops. Information was abstracted on authors, publication year, country and location, study design, sample size, outcomes investigated, and primary findings using a uniform checklist. Finally, we conducted a structured narrative synthesis of the main findings.

RESULTS

We obtained 61 studies, mostly from Eastern Africa, majority of which were conducted between 2006 and 2011. Outcome measures were heterogeneous and included knowledge, characteristics, and dispensing and regulatory practices. Shop location and client demand were found to strongly influence dispensing practices. Whereas shops located in urban and affluent areas were more likely to provide correct treatments, those in rural areas provided credit facilities more readily. However, the latter also charged higher prices for medicines. A vast majority of shops simply sold whatever medicines clients requested, with little history taking and counseling. Most shops also stocked popular medicines at the expense of policy recommended treatments. Treatment policies were poorly communicated overall, which partly explained why staff had poor knowledge on key aspects of treatment such as medicine dosage and side effects. Overall, very little is known on the link between regulatory enforcement and practices of specialized drug shops.

CONCLUSIONS

Evidence suggests that characteristics and practices of specialized drug shops differ across rural and urban locations, and that these providers are highly responsive to client demand. However, there is a dearth in knowledge on how regulatory enforcement influences their characteristics and practices, and what strategies can be employed to strengthen the governance of the retail pharmaceutical sector.

Got ACTs? Availability, price, market share and provider knowledge of anti-malarial medicines in public and private sector outlets in six malaria-endemic countries

Background

Artemisinin-based combination therapy (ACT) is the first-line malaria treatment throughout most of the malaria-endemic world. Data on ACT availability, price and market share are needed to provide a firm evidence base from which to assess the current situation concerning quality-assured ACT supply. This paper presents supply side data from ACTwatch outlet surveys in Benin, the Democratic Republic of Congo (DRC), Madagascar, Nigeria, Uganda and Zambia.

Methods

Between March 2009 and June 2010, nationally representative surveys of outlets providing anti-malarials to consumers were conducted. A census of all outlets with the potential to provide anti-malarials was conducted in clusters sampled randomly.

Results

28,263 outlets were censused, 51,158 anti-malarials were audited, and 9,118 providers interviewed. The proportion of public health facilities with at least one first-line quality-assured ACT in stock ranged between 43% and 85%. Among private sector outlets stocking at least one anti-malarial, non-artemisinin therapies, such as chloroquine and sulphadoxine-pyrimethamine, were widely available (> 95% of outlets) as compared to first-line quality-assured ACT (< 25%). In the public/not-for-profit sector, first-line quality-assured ACT was available for free in all countries except Benin and the DRC (US$1.29 [Inter Quartile Range (IQR): $1.29-$1.29] and $0.52[IQR: $0.00-$1.29] per adult equivalent dose respectively). In the private sector, first-line quality-assured ACT was 5-24 times more expensive than non-artemisinin therapies. The exception was Madagascar where, due to national social marketing of subsidized ACT, the price of first-line quality-assured ACT ($0.14 [IQR: $0.10, $0.57]) was significantly lower than the most popular treatment (chloroquine, $0.36 [IQR: $0.36, $0.36]). Quality-assured ACT accounted for less than 25% of total anti-malarial volumes; private-sector quality-assured ACT volumes represented less than 6% of the total market share. Most anti-malarials were distributed through the private sector, but often comprised non-artemisinin therapies, and in the DRC and Nigeria, oral artemisinin monotherapies. Provider knowledge of the first-line treatment was significantly lower in the private sector than in the public/not-for-profit sector.

Conclusions

These standardized, nationally representative results demonstrate the typically low availability, low market share and high prices of ACT, in the private sector where most anti-malarials are accessed, with some exceptions. The results confirm that there is substantial room to improve availability and affordability of ACT treatment in the surveyed countries. The data will also be useful for monitoring the impact of interventions such as the Affordable Medicines Facility for malaria.

Increased prevalence of the pfdhfr/phdhps quintuple mutant and rapid emergence of pfdhps resistance mutations at codons 581 and 613 in Kisumu, Kenya

Background

Anti-malarial drug resistance in Kenya prompted two drug policy changes within a decade: sulphadoxine-pyrimethamine (SP) replaced chloroquine (CQ) as the first-line anti-malarial in 1998 and artemether-lumefantrine (AL) replaced SP in 2004. Two cross-sectional studies were conducted to monitor changes in the prevalence of molecular markers of drug resistance over the period in which SP was used as the first-line anti-malarial. The baseline study was carried out from 1999-2000, shortly after implementation of SP, and the follow-up study occurred from 2003-2005, during the transition to AL.

Materials and methods

Blood was collected from malaria smear-positive, symptomatic patients presenting to outpatient centers in Kisumu, Kenya, during the baseline and follow-up studies. Isolates were genotyped at codons associated with SP and CQ resistance. In vitro IC₅₀ values for antifolates and quinolones were determined for isolates from the follow-up study.

Results

The prevalence of isolates containing the pfdhfr N51I/C59R/S108N/pfdhps A437G/K540E quintuple mutant associated with SP-resistance rose from 21% in the baseline study to 53% in the follow-up study (p < 0.001). Isolates containing the pfdhfr I164L mutation were absent from both studies. The pfdhps mutations A581G and A613S/T were absent from the baseline study but were present in 85% and 61%, respectively, of isolates from the follow-up study. At follow-up, parasites with mutations at five pfdhps codons, 436, 437, 540, 581, and 613, accounted for 39% of isolates. The CQ resistance-associated mutations pfcrt K76T and pfmdr1 N86Y rose from 82% to 97% (p = 0.001) and 44% to 76% (p < 0.001), respectively, from baseline to follow-up.

Conclusions

During the period in which SP was the first-line anti-malarial in Kenya, highly SP-resistant parasites emerged, including isolates harboring pfdhps mutations not previously observed there. SP continues to be widely used in Kenya; however, given the highly resistant genotypes observed in this study, its use as a first-line anti-malarial should be discouraged, particularly for populations without acquired immunity to malaria. The increase in the pfcrt K76T prevalence, despite efforts to reduce CQ use, suggests that either these efforts are not adequate to alleviate CQ pressure in Kisumu, or that drug pressure is derived from another source, such as the second-line anti-malarial amodiaquine.

Barriers to prompt and effective malaria treatment among the poorest population in Kenya

BACKGROUND

Prompt access to effective malaria treatment is central to the success of malaria control worldwide, but few fevers are treated with effective anti-malarials within 24 hours of symptoms onset. The last two decades saw an upsurge of initiatives to improve access to effective malaria treatment in many parts of sub-Saharan Africa. Evidence suggests that the poorest populations remain least likely to seek prompt and effective treatment, but the factors that prevent them from accessing interventions are not well understood. With plans under way to subsidize ACT heavily in Kenya and other parts of Africa, there is urgent need to identify policy actions to promote access among the poor. This paper explores access barriers to effective malaria treatment among the poorest population in four malaria endemic districts in Kenya.

METHODS

The study was conducted in the poorest areas of four malaria endemic districts in Kenya. Multiple data collection methods were applied including: a cross-sectional survey (n=708 households); 24 focus group discussions; semi-structured interviews with health workers (n=34); and patient exit interviews (n=359).

RESULTS

Multiple factors related to affordability, acceptability and availability interact to influence access to prompt and effective treatment. Regarding affordability, about 40 percent of individuals who self-treated using shop-bought drugs and 42 percent who visited a formal health facility reported not having enough money to pay for treatment, and having to adopt coping strategies including borrowing money and getting treatment on credit in order to access care. Other factors influencing affordability were seasonality of illness and income sources, transport costs, and unofficial payments. Regarding acceptability, the major interrelated factors identified were provider patient relationship, patient expectations, beliefs on illness causation, perceived effectiveness of treatment, distrust in the quality of care and poor adherence to treatment regimes. Availability barriers identified were related to facility opening hours, organization of health care services, drug and staff shortages.

CONCLUSIONS

Ensuring that all individuals suffering from malaria have prompt access to effective treatment remains a challenge for resource constrained health systems. Policy actions to address the multiple barriers of access should be designed around access dimensions, and should include broad interventions to revitalize the public health care system. Unless additional efforts are directed towards addressing access barriers among the poor and vulnerable, malaria will remain a major cause of morbidity and mortality in sub-Saharan Africa.

Retail sector distribution chains for malaria treatment in the developing world: a review of the literature

Background

In many low-income countries, the retail sector plays an important role in the treatment of malaria and is increasingly being considered as a channel for improving medicine availability. Retailers are the last link in a distribution chain and their supply sources are likely to have an important influence on the availability, quality and price of malaria treatment. This article presents the findings of a systematic literature review on the retail sector distribution chain for malaria treatment in low and middle-income countries.

Methods

Publication databases were searched using key terms relevant to the distribution chain serving all types of anti-malarial retailers. Organizations involved in malaria treatment and distribution chain related activities were contacted to identify unpublished studies.

Results

A total of 32 references distributed across 12 developing countries were identified. The distribution chain had a pyramid shape with numerous suppliers at the bottom and fewer at the top. The chain supplying rural and less-formal outlets was made of more levels than that serving urban and more formal outlets. Wholesale markets tended to be relatively concentrated, especially at the top of the chain where few importers accounted for most of the anti-malarial volumes sold. Wholesale price mark-ups varied across chain levels, ranging from 27% to 99% at the top of the chain, 8% at intermediate level (one study only) and 2% to 67% at the level supplying retailers directly. Retail mark-ups tended to be higher, and varied across outlet types, ranging from 3% to 566% in pharmacies, 29% to 669% in drug shops and 100% to 233% in general shops. Information on pricing determinants was very limited.

Conclusions

Evidence on the distribution chain for retail sector malaria treatment was mainly descriptive and lacked representative data on a national scale. These are important limitations in the advent of the Affordable Medicine Facility for Malaria, which aims to increase consumer access to artemisinin-based combination therapy (ACT), through a subsidy introduced at the top of the distribution chain. This review calls for rigorous distribution chain analysis, notably on the factors that influence ACT availability and prices in order to contribute to efforts towards improved access to effective malaria treatment.

Reviewing the literature on access to prompt and effective malaria treatment in Kenya: implications for meeting the Abuja targets

Background

Effective case management is central to reducing malaria mortality and morbidity worldwide, but only a minority of those affected by malaria, have access to prompt effective treatment.

In Kenya, the Division of Malaria Control is committed to ensuring that 80 percent of childhood fevers are treated with effective anti-malarial medicines within 24 hours of fever onset, but this target is largely unmet. This review aimed to document evidence on access to effective malaria treatment in Kenya, identify factors that influence access, and make recommendations on how to improve prompt access to effective malaria treatment. Since treatment-seeking patterns for malaria are similar in many settings in sub-Saharan Africa, the findings presented in this review have important lessons for other malaria endemic countries.

Methods

Internet searches were conducted in PUBMED (MEDLINE) and HINARI databases using specific search terms and strategies. Grey literature was obtained by soliciting reports from individual researchers working in the treatment-seeking field, from websites of major organizations involved in malaria control and from international reports.

Results

The review indicated that malaria treatment-seeking occurs mostly in the informal sector; that most fevers are treated, but treatment is often ineffective. Irrational drug use was identified as a problem in most studies, but determinants of this behaviour were not documented. Availability of non-recommended medicines over-the-counter and the presence of substandard anti-malarials in the market are well documented. Demand side determinants of access include perception of illness causes, severity and timing of treatment, perceptions of treatment efficacy, simplicity of regimens and ability to pay. Supply side determinants include distance to health facilities, availability of medicines, prescribing and dispensing practices and quality of medicines. Policy level factors are around the complexity and unclear messages regarding drug policy changes.

Conclusion

Kenya, like many other African countries, is still far from achieving the Abuja targets. The government, with support from donors, should invest adequately in mechanisms that promote access to effective treatment. Such approaches should focus on factors influencing multiple dimensions of access and will require the cooperation of all stakeholders working in malaria control.

A stratified random survey of the proportion of poor quality oral artesunate sold at medicine outlets in the Lao PDR - implications for therapeutic failure and drug resistance

BACKGROUND

Counterfeit oral artesunate has been a major public health problem in mainland SE Asia, impeding malaria control. A countrywide stratified random survey was performed to determine the availability and quality of oral artesunate in pharmacies and outlets (shops selling medicines) in the Lao PDR (Laos).

METHODS

In 2003, 'mystery' shoppers were asked to buy artesunate tablets from 180 outlets in 12 of the 18 Lao provinces. Outlets were selected using stratified random sampling by investigators not involved in sampling. Samples were analysed for packaging characteristics, by the Fast Red Dye test, high-performance liquid chromatography (HPLC), mass spectrometry (MS), X-ray diffractometry and pollen analysis.

RESULTS

Of 180 outlets sampled, 25 (13.9%) sold oral artesunate. Outlets selling artesunate were more commonly found in the more malarious southern Laos. Of the 25 outlets, 22 (88%; 95%CI 68-97%) sold counterfeit artesunate, as defined by packaging and chemistry. No artesunate was detected in the counterfeits by any of the chemical analysis techniques and analysis of the packaging demonstrated seven different counterfeit types. There was complete agreement between the Fast Red dye test, HPLC and MS analysis. A wide variety of wrong active ingredients were found by MS. Of great concern, 4/27 (14.8%) fakes contained detectable amounts of artemisinin (0.26-115.7 mg/tablet).

CONCLUSION

This random survey confirms results from previous convenience surveys that counterfeit artesunate is a severe public health problem. The presence of artemisinin in counterfeits may encourage malaria resistance to artemisinin derivatives. With increasing accessibility of artemisinin-derivative combination therapy (ACT) in Laos, the removal of artesunate monotherapy from pharmacies may be an effective intervention.

Chloroquine resistance before and after its withdrawal in Kenya

BACKGROUND

The spread of resistance to chloroquine (CQ) led to its withdrawal from use in most countries in sub-Saharan Africa in the 1990s. In Malawi, this withdrawal was followed by a rapid reduction in the frequency of resistance to the point where the drug is now considered to be effective once again, just nine years after its withdrawal. In this report, the polymorphisms of markers associated with CQ-resistance against Plasmodium falciparum isolates from coastal Kenya (Kilifi) were investigated, from 1993, prior to the withdrawal of CQ, to 2006, seven years after its withdrawal. Changes to those that occurred in the dihydrofolate reductase gene (dhfr) that confers resistance to the replacement drug, pyrimethamine/sulphadoxine were also compared.

METHODS

Mutations associated with CQ resistance, at codons 76 of pfcrt, at 86 of pfmdr1, and at codons 51, 59 and 164 of dhfr were analysed using PCR-restriction enzyme methods. In total, 406, 240 and 323 isolates were genotyped for pfcrt-76, pfmdr1-86 and dhfr, respectively.

RESULTS

From 1993 to 2006, the frequency of the pfcrt-76 mutant significantly decreased from around 95% to 60%, while the frequency of pfmdr1-86 did not decline, remaining around 75%. Though the frequency of dhfr mutants was already high (around 80%) at the start of the study, this frequency increased to above 95% during the study period. Mutation at codon 164 of dhfr was analysed in 2006 samples, and none of them had this mutation.

CONCLUSION

In accord with the study in Malawi, a reduction in resistance to CQ following official withdrawal in 1999 was found, but unlike Malawi, the decline of resistance to CQ in Kilifi was much slower. It is estimated that, at current rates of decline, it will take 13 more years for the clinical efficacy of CQ to be restored in Kilifi. In addition, CQ resistance was declining before the drug's official withdrawal, suggesting that, prior to the official ban, the use of CQ had decreased, probably due to its poor clinical effectiveness.

Guidelines for field surveys of the quality of medicines: a proposal

Paul Newton and colleagues propose guidelines for conducting and reporting field surveys of the quality of medicines.

Availability and choice of antimalarials at medicine outlets in Ghana: the question of access to effective medicines for malaria control

Although national and international efforts to combat malaria have intensified over the years, problems with availability, distribution, and choice of antimalarials at medicine outlets in Africa continue to exist. This article presents the results of an indicator-based assessment of availability and choice of antimalarials at 130 licensed medicine outlets in Ghana. We also discuss how the choice of an antimalarial to dispense conforms to recommendations of the national policy for malaria therapy. Data were obtained through face-to-face interviews, by reviewing facility records, and by observing the practices of dispensing staff in the medicine outlets. Antimalarials recommended in the policy were not readily available in the most accessible medicine outlets. Few outlets adhered to the policy when choosing antimalarials. Interventions targeting medicine outlets should be initiated to improve availability and access to effective medicines in order to support the national program for malaria control.

Medicine sellers and malaria treatment in sub-Saharan Africa: what do they do and how can their practice be improved?

Medicine sellers are widely used for fever and malaria treatment in sub-Saharan Africa, but concerns surround the appropriateness of drugs and information provided. Because there is increasing interest in improving their services, we reviewed the literature on their characteristics and interventions to improve their malaria-related practices. Sixteen interventions were identified, involving a mixture of training/capacity building, demand generation, quality assurance, and creating an enabling environment. Although evidence is insufficient to prove which approaches are superior, tentative conclusions were possible. Interventions increased rates of appropriate treatment, and medicine sellers were willing to participate. Features of successful interventions included a comprehensive situation analysis of the legal and market environment; buy-in from medicine sellers, community members and government; use of a combination of approaches; and maintenance of training and supervision. Interventions must be adapted to include artemisinin-based combination therapies, and their sustainability and potential to operate at a national level should be further explored.

Artemether/lumefantrine in the treatment of uncomplicated falciparum malaria

At present, artemether/lumefantrine (AL) is the only fixed-dose artemisinin-based combination therapy recommended and pre-qualified by WHO for the treatment of uncomplicated malaria caused by Plasmodium falciparum. It has been shown to be effective both in sub-Saharan Africa and in areas with multi-drug resistant P. falciparum in southeast Asia. It is currently recommended as first-line treatment for uncomplicated malaria in several countries. However, AL has a complex treatment regimen and the issues of adherence to treatment with AL by adult patients and real-life effectiveness in resource-poor settings will be critical in determining its useful therapeutic life, especially in Africa, where the major burden of malaria is felt. There are also issues of safety of the artemisinin derivatives, including AL, which will need to be monitored as their use in resource-poor settings becomes more widespread. There are limited pharmacokinetic studies of AL in African patients, and the relationship between plasma drug concentration and efficacy in these patients is unknown. Moreover, the effects of factors such as concurrently administered drugs, malnutrition and co-infections with HIV and helminths in malaria patients are not well understood. These will need to be addressed, although a few studies on possible drug-drug interactions with commonly used drugs, such as quinine, mefloquine and ketoconazole, have been reported. This review focuses on the status of clinical pharmacology, efficacy and real-life effectiveness of AL under a variety of settings, and highlights some of the challenges that face policy makers during the deployment of AL, especially in Africa, with regards to ensuring that those who most need this therapy will not be denied access due to official inefficiency in procurement and distribution processes.

Simultaneous quantitative analysis of the antimalarials pyrimethamine and sulfamethoxypyrazine in plasma samples using liquid chromatography/tandem mass spectrometry

The work presented here deals with the development of a quantitative tool for the simultaneous determination of sulfamethoxypyrazine (sulfalene)/pyrimethamine in plasma. The chromatography used only takes 12.5 min, allowing a fast sample turnover time. Relative standard deviation of retention times was never above 3.48% (n = 66). Adequate sample clean-up was achieved by a simple and relatively fast liquid/liquid extraction. In this way, ionisation suppression effects, typical for more simple sample clean-up procedures, could be avoided resulting in absolute plasma effects of maximum -17.1% for sulfalene, -16.1 for the internal standard (IS), and 12% for pyrimethamine. For both pyrimethamine and sulfalene, quadratic calibration curves from 0.00101 to 0.807 microg/mL for pyrimethamine and from 0.271 to 216 microg/mL for sulfalene gave the best fit. Mean coefficients of determination (R2) were 0.9951 (n = 6, CV% 0.39) for pyrimethamine and 0.9942 (n = 6, CV% 0.13) for sulfalene. Precision was below 9.35% for pyrimethamine and 13.9% for sulfalene. Inaccuracy remained below 15% at all cases. The optimised method was used for a time-course study of the sulfalene/pyrimethamine combination concentration in plasma of patients treated with Co-Arinate, a new curative antimalaria-medicine.

The quality of sulphadoxine-pyrimethamine and amodiaquine products in the Kenyan retail sector

BACKGROUND AND OBJECTIVE

Malaria is a disease of major public health importance in Kenya killing 26,000 children under 5 years of age annually. This paper seeks to assess the quality of sulphadoxine-pyrimethamine (SP) and amodiaquine (AQ) products available over-the-counter to communities in Kenya as most malaria fevers are self-medicated using drugs from the informal retail sector.

METHODS

A retail audit of 880 retail outlets was carried in 2002 in four districts in Kenya, in which antimalarial drug stocks and their primary wholesale sources were noted. In addition, the expiry dates on audited products and the basic storage conditions were recorded on a proforma. The most commonly stocked SP and AQ products were then sampled from the top 10 wholesalers in each district and samples subjected to standard United States Pharmacopoeia (USP) tests of content and dissolution.

RESULTS AND DISCUSSION

SP and AQ were the most frequently stocked antimalarial drugs, accounting for approximately 75% of all the antimalarial drugs stocked in the four districts. Of 116 SP and AQ samples analysed, 47 (40.5%) did not meet the USP specifications for content and/or dissolution. Overall, approximately 45.3% of SP and 33.0% of AQ samples were found to be sub-standard. Of the sub-standard SP products, 55.2% were suspensions while 61.1% of the substandard AQ products were tablets. Most SP failures were because of the pyrimethamine component.

CONCLUSION

There is a need to strengthen post-marketing surveillance systems to protect patients from being treated with sub-standard and counterfeit antimalarial drugs in Kenya.