1. Introduction

The WHO Expert Committee on the Use of Essential Drugs met in Geneva from 1 to 5 December 1997. The meeting was opened on behalf of the Director-General by Mr D. Aitken, Assistant Director-General, who emphasized that the concept of essential drugs was fundamental both to WHO’S revised drug strategy (1), as endorsed by the World Health Assembly in resolution WHA39.27 in 1986 (2), and to the development of national drug policies. Regular updating of WHO’S Model List of Essential Drugs sustained the momentum of the revised drug strategy and was a basic element of the validated information required by most of WHO’S Member States for optimal rationalization of drug procurement and supply. Mr Aitken also emphasized the importance of the emergence of resistance to antimicrobials that, in many cases, is dangerously eroding their effectiveness. This is leading to a situation whereby it will be increasingly difficult to combat serious infections.

The Committee decided to prepare its report as a self-contained document and to incorporate into it those parts of the previous report (3) that required no modification or merely bringing up to date. The tenth Model List of Essential Drugs will be found in section 15 of this report, and explanations of the changes in section 16.

In a report (4) to the Twenty-eighth World Health Assembly in 1975, the Director-General reviewed the main drug problems facing the developing countries and outlined possible new drug policies. The Director-General also referred to the experience gained in some countries where schemes of basic or essential drugs had been implemented. Such schemes were intended to extend the accessibility and rational use of the most necessary drugs to populations whose basic health needs could not be met by the existing supply system. The Director-General pointed out that the selection of these essential drugs would depend on the health needs and on the structure and development of the health services of each country. Lists of essential drugs should be drawn up locally, and periodically updated, with the advice of experts in public health, medicine, pharmacology, pharmacy and drug management. He also considered that adequate information on the properties, indications and use of the drugs listed should be provided. By resolution WHA28.66 (5), the Health Assembly requested the Director-General to implement the proposals contained in his report and, in particular, to advise Member States on the selection and procurement, at reasonable cost, of essential drugs of established quality corresponding to their national health needs.

Following wide consultation, an initial Model List of Essential Drugs was included in the first report of the Expert Committee on the Selection of Essential Drugs (6). This has subsequently been revised and updated in eight further reports (3, 7-13).

In undertaking a further review of the list at its present meeting, the Expert Committee was guided throughout by the following statement contained in the previous reports:

Because of the great differences between countries, the preparation of a drug list of uniform, general applicability is not feasible or possible. Therefore, each country has the direct responsibility of evaluating and adopting a list of essential drugs, according to its own policy in the field of health.

The list of essential drugs based on the guidelines put forward in this report is a model which can furnish a basis for countries to identify their own priorities and to make their own selection.

The Committee reviewed the evolution of the Model List of Essential Drugs during the past 20 years and confirmed the definition of essential drugs as those that satisfy the health care needs of the majority of the population; they should therefore be available at all times in adequate amounts and in the appropriate dosage forms. Model lists have proved to be invaluable in reducing costs and meeting the health needs of populations through more rational use of drugs and wider access to drugs of acceptable quality. The Committee considered model lists as informational and educational tools for health professionals and consumers. Since concern about health care costs is now a priority even in developed countries, model lists are of greater importance than ever for the development of treatment guidelines, national formularies, information for patients and the general public, and other measures to improve drug use. The Committee emphasized that model lists should be seen in the context of comprehensive national drug formularies which address not only drug use but also strategies for drug procurement and supply, drug financing, drug donations, research priorities for drug use and drugs needed for specific diseases.