Essential Medicines & Rational Drug Use

The essential medicines concept & rationale

• WHO definition — essential medicines are those that satisfy the priority healthcare needs of the population, selected with due regard to public-health relevance, evidence on efficacy & safety, and comparative cost-effectiveness.
• The "5 A's" — they should be available at all times, in adequate amounts, in appropriate dosage forms, with assured quality & adequate information, and at a price the individual and community can afford (availability · affordability · appropriate dosage form · assured quality · adequate information).
• Underlying rationale — only a handful of the multitude of marketed medicines can meet the needs of the majority; many older, well-tested, cheaper drugs are equally (or more) efficacious and safe as newer expensive congeners — so governments, especially in developing countries, should concentrate resources on identifying these.
• Documented benefits of an EML — improved availability; cost saving; more rational use of drugs; basis for national formularies & a short list to guide community health workers in primary care; emphasises the need for drug R&D before EML inclusion.
• Terminology — the modern WHO term is essential medicines (2002 rename from essential drugs); the two are used interchangeably in older texts. Use "essential medicines / WHO EML / NLEM".