In its efforts to promote safe and cost-effective use of medicines, WHO has recently released the first edition of the WHO Model Formulary. The Formulary is the first global publication to give comprehensive information on all 325 medicines contained in the WHO Model List of Essential Medicines. It presents information on the recommended use, dosage, adverse effects, contraindications and warnings of these medicines. Correct use of this tool will improve patient safety and limit superfluous medical spending.

A look at some statistics shows why the need for such a formulary is so great. Bad prescribing habits are very common in all countries of the world and overuse, under-use and misuse of medicines remain widespread. For example, 30-60% of patients in primary health care centres receive antibiotics (perhaps twice what is clinically needed); 25-75% of antibiotic prescriptions in teaching hospitals are inappropriate; half of the 15 billion injections given world wide each year are not sterile; and many of these are not even needed. Only one in two countries actively regulate drug promotion, and less than 50% of people with chronic illnesses, such as diabetes and hypertension, adhere to prescribed treatment. Ineffective and unsafe treatment leads to exacerbation or prolongation of illness and harm to the patient. In addition, inappropriate treatment increases the costs to the patient, the insurance system or the government.

Evidence-based selection

Rational drug use depends heavily on selecting essential medicines that reflect the best combination of efficacy, safety and comparative cost-effectiveness. Their selection should be evidence-based and free from commercial influence. In 2002, WHO introduced new procedures aimed at establishing a model selection process for updating its Model List of Essential Medicines. This new process now includes tying selection directly to treatment guidelines, preparing systematic reviews of the clinical evidence for proposed choices, and making this evidence publicly available in advance of decision-making meetings. This means that there is an opportunity for all stake-holders (including industry and patient advocacy groups) to comment on proposed changes in the List, before taking the final decisions in a closed meeting of independent experts, and publicly documenting the reasons for each decision.

Effective use of medicines also depends on the actions of health care providers, formal and informal distribution channels, the pharmaceutical industry and the public. Over the last decade, through the efforts of the International Network for Rational Use of Drugs (INRUD), and a host of operational research initiatives, much has been learned about improving the use of medicines. For example, it has been shown that interventions such as unfocused drug information, treatment guidelines without active follow-up, and non-interactive communication efforts have no measurable impact. On the other hand, standard treatment guidelines supported by effective training programmes have been shown to reduce mortality from acute respiratory infections in children. Targeted training of licensed drug sellers can increase dispensing of effective treatment and reduce dispensing of unsafe ones for diarrhoea and acute respiratory infections; and interactive group discussions involving prescribers and mothers can dramatically reduce the overuse of injections. The challenge for health policy-makers is to learn from these lessons and act accordingly.

It is estimated that only two-thirds of developing country populations have some form of access to essential medicines. For those countries, pharmaceuticals can represent as much as 40% of the health budget. Because of the considerable impact on the quality of care and the cost of treatment, the selection of essential medicines, and their appropriate use, constitute the most effective approach to improving equitable access to health care. This principle also applies to industrialised countries, where details of medical insurance coverage are always important concerns for the public, and central to policy debates. For example, in Europe and North America annual medicine expenditure increases of 10-18% in 1999-2001 are raising concerns among public reimbursement schemes and health insurers. Prepayment and insurance schemes have all found that application of the essential medicines concept is critical to the financial viability of such programmes - no insurance system can afford to reimburse all medicines available on the market.

The WHO Model List of Essential Medicines, recently updated to include 12 essential antiretroviral medicines for the treatment of HIV/AIDS, focuses pharmaceutical efforts on priority conditions and quality medicines that are the most cost-effective, safe and affordable possible. For instance, the vast majority of medicines contained in the Model List are well-known and well-established pharmaceuticals which are off patent and available from many sources.

Adapting to national needs

The new Formulary is primarily intended as a model for national governments and institutions, to be used as a basis for creating their own national formularies. It is particularly relevant for developing countries, where commercial and promotional materials are often the only available source of drug information for health workers, prescribers and patients. The WHO Formulary may also be useful for individual prescribers - and for this reason it is available at reduced cost for developing countries.

The Model List of Essential Medicines and the Model Formulary constitute the backbone of the new WHO Essential Medicines Library (www.who.int/medicines), which is being developed. Visitors to this site will find the reasons drugs were included on the Model List, the underlying evidence, price information and normative information, such as International Nonproprietary Names (INN), International Pharmacopoeia monographs, and the Anatomic, Therapeutic and Chemical (ATC) and Defined Daily Dosage (DDD) classifications. To make access to information as wide as possible, the WHO Model Formulary is available both in PDF format and as a searchable database. A CD-ROM version is in preparation.

National and institutional committees can also decide to use the WHO Model Formulary as a starting point for their own formularies. Rather than starting from scratch they can use the existing WHO text and adapt this to their local conditions. They can do this by eliminating medicines which do not figure on their national list, entering other medicines from their national list, and adding specific information on national products, brand names, product specifications and prices. It should be stressed, however, that the availability of this WHO text should not be used to cut short on the development process of a national or institutional formulary. An essential condition for the acceptability and use of a formulary is a development and review process which involves wide consultation among future users. Formulary committees interested in this approach should contact their national or regional WHO offices for advice.