Essential medicines, as defined by the World Health Organization are "those drugs 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 appropriate dosage forms, at a price the community can afford.
Essential medicines are those that satisfy the priority health care needs of the population. They are selected with due regard to public health relevance, 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 adequate information, and at a price the individual and the community can afford. 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.
Cost effectiveness is the subject of fierce debate between producers and purchasers of drugs.The number of medications has nearly doubled, from the original 208 in 1977 to more than 340.The range has increased over the years and now includes an antimigraine drug, antidotes, and antineoplastic drugs. The third list for children from 2011 contains 269 medications.