Introduction

The 20th century witnessed revolutionary progress in improving human health, leading to dramatic declines in mortality and equally dramatic increases in life expectancy. Income growth, higher educational levels, improved sanitation and better food all contributed to this progress. The development of pharmaceuticals, particularly essential medicines, also played an important role (WHO 1999).

The work of the world’s leading international public health agency, the World Health Organization (WHO), covers numerous health-related technical areas, supporting its overall objective of ‘the attainment by all peoples of the highest level of health’. Much has been achieved in the pharmaceutical sector since the essential medicines concept was introduced in 1975 and the first Model List of Essential Medicines was launched in 1977. Today, three out of four countries in the world have national essential medicines lists as the basis for public procurement, reimbursement schemes, training, supervision and patient information (WHO 2004a). More importantly, in 1977 less than half the world’s population had regular access to essential medicines. Today, through a combination of public and private health systems, nearly two-thirds of the world’s population is estimated to have access to effective treatments essential for their health needs (WHO 2004a). Essential medicines are one of the most cost-effective elements in modern health care.

The World Health Organization

Established in 1948, WHO is a specialized agency of the United Nations system. It is the technical and professional body concerned with international public health issues. When WHO was endorsed on 7 April 1948 by the United Nations it had fewer than 60 member states; in 2007, it had 193 (WHO 2007a). Its definition of health and its overall objective are provided in Box 7.1 (WHO 2007b).

WHO can offer a range of opportunities for cooperating with its member states, with its headquarters in Geneva, Switzerland, dealing with global issues, and its six regional offices focusing on technical support and national capacity building. The organization’s presence in 147 countries allows a close relationship with ministries of health (WHO 2007a). WHO was in official relations with almost 190 non-governmental and voluntary organizations involved in health promotion and healthcare provision in 2006 (WHO 2007a). It also collaborates closely with the other agencies of the United Nations system in health-related activities (WHO 2007a). Increasingly, WHO plays a leading role in various public health-related initiatives, the so-called public–private partnerships, which should be seen as public sector programmes with private or commercial sector participation (WHO 2008).

WHO continues to promote the efforts of international health cooperation that was initiated by the first International Sanitary Conference in Paris in 1851, when nations joined forces to combat common health threats such as plague, yellow fever, cholera, leprosy, tuberculosis, smallpox and typhus. Some of these diseases still exist today, though smallpox has been eradicated and other diseases are in the process of being eliminated, for example polio, measles and leprosy (WHO 2007c).

In 1897, aspirin was introduced as the first synthetic pharmaceutical product. The 20th century saw the discovery and further development of pharmaceutical products, such as the introduction of penicillin (1928), the measles vaccine (1943), streptomycin, the first antitubercular drug (1945) and chloroquine, the first antimalarial drug (1946). In the 1950s the first clinical uses of oral contraceptives and of medicines for diabetes and mental illness were introduced, and later medicines for other infectious and cardiovascular diseases (WHO 2007c).

Also in the 20th century, there were significant gains in life expectancy of 20–40 years worldwide. This was mainly due to declining infant and child mortality rates, maternal mortality rates and fertility rates, a drastic reduction in the disease burden of infectious diseases caused by effective preventive actions and improved treatment. In addition, general sanitation measures and immunization programmes were implemented. These achievements were the results of dedicated international health efforts (WHO 1999, 2007c).

Despite these successes, the current situation indicates that not all people have benefited equally from improvements in health status and access to healthcare services. It is estimated that more than 1 billion people are still excluded from adequate health care (WHO 1999). Low income countries face ill health, mainly through communicable diseases, due to poverty-related conditions such as inadequate food, water and sanitation, housing, education and health services. The emergence of the HIV epidemic, the resurgence of tuberculosis and malaria, and tobacco-related diseases are also factors. In high income countries ill health, mainly through non-communicable diseases, results mainly from excessive eating, drinking and smoking, using and abusing narcotic medicines, and from environmental pollution and urbanization (WHO 1999).

Based on the experience of containing severe acute respiratory syndrome (SARS) and the threat of an avian flu outbreak worldwide, WHO is reinforcing its lead role in limiting the international spread of epidemics and other public health emergencies. The organization has to consider this diversity of health challenges in order to develop strategies and programmes to meet the health needs of its member states (WHO 2007c).

WHO fulfils its objectives through its core functions which underpin the global health agenda set out in a framework for an organization-wide programme of work, and is linked to the achievement of the millennium development goals. WHO’s six core functions can be divided into normative work and technical cooperation and are listed below (WHO 2007d):

The global health agenda is a guide for all stakeholders, not for WHO alone, and it outlines seven priority areas. The first three areas are closely related to health: investing in health to reduce poverty; building individual and global health security; and promoting universal coverage, gender equality and health-related human rights. The other four areas focus on specific tasks such as: tackling the determinants of health; strengthening health systems and equitable access; harnessing knowledge, science and technology; and strengthening governance, leadership and accountability (WHO 2007d).

Many countries rely on WHO norms and standards, including quality assurance, especially for biological, pharmaceutical and diagnostic products. WHO will continue to encourage efforts, including those of industry, to develop new and affordable biological, pharmaceutical and diagnostic products. WHO has expanded its global normative work after the adoption by its member states of the WHO Framework Convention for Tobacco Control and the revised International Health Regulations in 2005 and through the establishment of its commissions on macroeconomics and health (2002), intellectual property rights, innovation and public health (2003), and the social determinants of health (2005) (WHO 2007d).

WHO’s work in essential medicines

The departments of Medicines Policy and Standards (PSM) and Technical Cooperation for Essential Drugs and Traditional Medicine (TCM) are central to WHO’s goal in medicines to help save lives and improve health by ensuring the quality, efficacy, safety and rational use of medicines, including traditional medicines, and by promoting equitable and sustainable access to essential medicines, particularly for the poor and disadvantaged (WHO 2004a). Essential medicines are one of the most cost-effective elements in modern health care and their potential health and economic impact is considerable in terms of saving lives, reducing suffering, and protecting, maintaining and restoring health.

Besides norm and standard setting for essential medicines, WHO provides guidance on regulatory standards, defines international non-proprietary names, provides therapeutic advice, such as standard treatment guidelines, and produces a Model List of Essential Medicines and a Model Formulary. Technical assistance to member states is also provided on the development and implementation of their national medicines policies. A national medicines policy is a commitment to a goal and a guide for action, providing a framework in which the national goals, objectives and priorities are formulated for both the public and private pharmaceutical sectors. It identifies strategies needed to achieve these objectives (WHO 2004a).

The essential medicines concept

During the 1970s a growing number of low-income countries had more than 20 000 different brands of pharmaceutical products circulating in their markets. This situation was similar to that in high-income countries, despite the differences in their prevailing common diseases and their socio-economic positions. Also, pharmaceutical products were promoted and marketed with little concern for the different health needs and priorities of individual countries (WHO 2006a).

In the mid 1970s some governments of low-income countries (Costa Rica, Cuba and Sri Lanka) started to realize that if medicines were to meet the real health needs of the majority of their populations and be equally available to all, then criteria had to be set, especially for selection of medicines. The concept of essential medicines was born. This concept proved to have a positive impact on drug procurement, distribution, use and prices as well (WHO 2006a).

The concept of essential medicines is forward looking (Quick 1997). It incorporates the need to:

The concept of essential medicines encourages health systems to focus on access to those medicines that represent the best balance of quality, safety, efficacy and cost to meet the priority health needs within a given healthcare setting. The implementation of the concept of essential medicines is intended to be flexible and adaptable to many different situations; exactly which medicines are regarded as essential remains a national responsibility (Quick 1997).

The Model List of Essential Medicines

In 1977, inspired by the essential medicines concept, a WHO expert committee discussed the question of how many medicines were really needed to treat common health problems. It concluded that approximately 208 individual medicines and vaccines could be considered essential and together could provide safe, effective treatment for the majority of communicable and non-communicable diseases. Moreover, the majority of drug products were off patent and could be produced at relatively low cost (WHO 2006b). In the same year, the first Model List of Essential Drugs was published by WHO and has since been updated every 2 years. It was met with a mixture of surprise, opposition and enthusiasm by the medical and pharmaceutical establishment and created a revolution in international public health (Quick 1997).

Essential medicines are defined as those medicines that satisfy the priority healthcare needs of the population. Essential medicines are selected with due regard to disease prevalence, evidence on efficacy and safety, and comparative cost-effectiveness. Essential medicines are intended to be available within the context of functioning health systems at all times in adequate amounts, in the appropriate dosage forms, with assured quality, and at a price the individual and the community can afford.

The WHO Model List is a guide for the development of national and institutional essential medicine lists. It was not designed as a global attempt to establish a uniform medicines list, as this is neither feasible nor realistic. However, for the past 30 years the Model List has led to a global acceptance of the concept of essential medicines as a powerful means to promote health equity. By the end of 2003, 156 member states had official essential medicines lists, of which 99 had been updated in the previous 5 years. Most countries have national lists and some have provincial or state lists as well. National lists of essential medicines usually relate closely to national guidelines for clinical healthcare practice. Therefore, they can be used as decision-making tools for drug procurement in the public sector, for schemes that reimburse medicine costs, for medicine donations and local medicine production. Moreover, they can be used as educational tools for the training and supervision of health workers and used as informational tools for consumers (Quick 1997; Fig. 7.1). National lists should reflect the national priorities in medication needs. This does not imply that no other medicines are useful, but simply that in a given context those medicines selected are the ones most needed for the national health services. They should, therefore, be available at all times in adequate amounts and in the proper dosage forms (Quick 1997). Access to essential medicines of assured quality is fundamental for the optimal performance of a healthcare system. Uninterrupted supplies of essential medicines to a great extent determine the credibility of health services (Quick 1997).

Fig. 7.1 Relationship between treatment guidelines and a list of essential medicines (WHO 2002).

Many international organizations, including UNICEF, UNHCR and UNFPA as well as non-governmental organizations and international non-profit medicine supply agencies, have adopted the essential medicines concept and base their medicine supply lists largely on the WHO Model List (Quick 1997).

In 1999, the WHO Expert Committee on the Use of Essential Medicines reviewed the procedures for updating the Model List. They recommended to WHO that the process of developing the list should be seen as an example of a model drug evaluation procedure for national drug and therapeutics committees (Quick 1997). It should be a systematic and transparent process. In addition, the methods for updating the Model List should be revised because selection of medicines should be evidence based rather than consensus based, should have a clearer link between essential medicines and guidelines for clinical health care, and should consider the high cost of many new and effective medicines. At the beginning of 2002, the Model List was revised by the expert committee, applying the new procedure (Quick 1997).

The WHO Model Formulary

In 1995, the WHO expert committee recommended that WHO should develop a Model Formulary which would complement the WHO Model List. It would provide independent information on essential medicines for pharmaceutical policy makers and prescribers worldwide. A Model Formulary would be a useful resource for countries wishing to develop their own national formulary.

The first edition of the Model Formulary was launched in 2002 based on the 12th Model List. The electronic version of the Model Formulary is intended as a starting point for developing national or institutional formularies by adapting the text of the Model Formulary for their own national list of essential medicines. A third edition of the Model Formulary will be based on the 15th Model List (2007) and will be available in 2008 (WHO 2004b).

The need for essential medicines for children

Over thirty years ago, in 1977, the first Model List of Essential Drugs was launched. This list defined medicines that satisfy the priority healthcare needs of the population, but until now the Model List has not included many medicines specifically for children. Every year there are over 40 million deaths in developing countries and over 10 million among children under 5 years of age (WHO 2005). The six main causes of death are pneumonia, diarrhoea, malaria, preterm birth, asphyxia and pneumonia/sepsis in newborn babies and these account for 73% of all deaths in the under fives. In addition, AIDS claims over 300 000 deaths in children under 15 years annually. Under-nutrition is a contributing cause of death in over 60% of diarrhoea cases, 57% of malaria cases and 52% of pneumonia cases (WHO 2005).

For all these conditions, essential medicines are available and are life saving. However, access to safe, effective and affordable essential medicines for children (‘paediatric formulations’) remains a problem. In particular, the HIV pandemic has highlighted the urgent need for adequate formulations for children as well as for acute infectious diseases, where medicines are either not available on the market or not financially or geographically accessible (WHO 2007f).

Studies of current practice worldwide revealed that healthcare workers estimate the dose of medicines by assuming that children are small adults, which is physiologically incorrect. They often dispense medicines to small children by using fractions of adult dosage forms such as half or quarter tablets, or by crushing tablets or opening capsules – both meant for adults. These strategies are not recommended and can result in either under- or overdosing, with potential efficacy and safety problems. Even if formulations for children are available, many healthcare workers may not know how to prescribe these medicines appropriately (WHO 2007f).

In May 2007, the World Health Assembly endorsed the WHO resolution on ‘Better Medicines for Children’, including the development of a Model List of Essential Medicines for Children (WHO 2007f). Therefore, WHO updated their Model List of Essential Medicines to include essential medicines for children, based on their clinical needs and the burden of disease. This resulted in the publication of the first Essential Medicines List for Children in July 2007. Based on this list, WHO will identify the appropriate dosage forms and strengths of medicines for children, develop and promote quality standards and support mechanisms for licensing of children’s essential medicines by drug regulatory authorities. WHO will, in partnership with UNICEF, encourage manufacturers to develop appropriate medicines at affordable prices.

In view of the need to achieve the millennium development goals on the reduction of malnutrition and child and maternal mortality, and the focus of the director-general of WHO on improving health in Africa (WHO 2007a), developing a Model List of Essential Medicines for Children will become a powerful tool for reducing infant and child mortality.

Given that in 2007 it was 30 years since the first essential medicines list was published, this was also an opportunity for WHO to promote the essential medicines concept and WHO is looking to the future by creating a Model List of Essential Medicines for Children.

Conclusion

Over the years, the essential medicines concept has become a global concept and is a powerful tool to promote health equity. Although originally intended for low-income countries, an increasing number of high-income countries also use its key components. Health systems, from basic health systems in the poorest countries to highly developed national health insurance schemes in the industrialized countries, have recognized both its therapeutic and its economic benefits. This recognition has been triggered by the introduction of many new and often expensive drug therapies, increasing drug costs and by observed quality variations in healthcare provision (Quick 1997).

The essential medicines concept is now widely accepted as a highly pragmatic approach to providing the best of modern evidence-based and cost-effective health services. It is as valid today as it was when first introduced in 1975. The concept does not exclude all other medicines but focuses on those medicines that have the best balance of quality, safety, efficacy and cost for a given health service (Quick 1997). Moreover, the concept is forward looking. It stimulates research and development for better pharmaceutical formulations and for more efficient responses to new or re-emerging diseases. It has also been adopted by international and bilateral aid agencies and by non-governmental organizations that include strategies on rational drug selection, supply and use in their programmes of work (Quick 1997).

In its present form, the Model List aims to identify cost-effective medicines for priority conditions, together with the reasons for their inclusion, linked to evidence-based clinical guidelines and with special emphasis on public health aspects and considerations of value for money. Information that supports the selection of essential medicines, such as relevant WHO clinical guidelines, systematic reviews, key references and indicative cost information, is being made available via the WHO website. The Model List’s primary function is to facilitate the work of national and institutional committees in developing national and institutional lists of essential medicines.

Moreover, the list has also resulted in greater international coordination in healthcare development and in health emergency situations (Quick 1997). Linked to the Model List, the WHO Model Formulary provides independent information on essential medicines for pharmaceutical policy makers and prescribers worldwide. It is also a useful resource for countries wishing to develop their own national formulary (WHO 2004b).

Millions of children die each year because they do not have access to medicines that are child-specific. Access to safe, effective and affordable essential medicines for children is a global problem (WHO 2007f). There is an urgent need for adequate formulations in acute and chronic care and treatment of children. Medicines for children do not exist or are not available on the local market, or are unaffordable.

The WHO World Health Assembly resolution on ‘Better Medicines for Children’ supports the development of a Model List of Essential Medicines for Children which will identify the gaps in the range of medicines and formulations specifically for children (WHO 2007f).