WHO Model list of essential medicines.

https://en.wikipedia.org/wiki/WHO_Model_List_of_Essential_Medicines (accessed 12-2016).

The first list, published in 1977, included 204 pharmaceutical drugs.^[1] The WHO updates the list every two years. The WHO later added a separate WHO Model List of Essential Medicines for Children up to 12 years of age.

As of 2016, at least 156 countries have created national lists of essential medicines based on the WHO's model list.^[2] The national lists contain between 334 and 580 medications.^[3]