The information required for the distribution process comprises that needed to select and quantify drugs, and enough technical data to ensure proper conservation of those drugs.
Those involved in distribution should know what drugs are authorized in the country, what drugs are authorized in the different categories of the health services, and what drugs are listed as vital and essential in the VEN classification. In turn, the health services must know what drugs are available in the pharmacies. This information is not always sufficiently widely disseminated. Lack of information can cause stock shortages or impressions of shortages if drugs that have not been distributed are prescribed or if drugs that have been distributed are not prescribed.
Calculating the quantities of drugs needed requires information at several levels. Skilled management of stock in a pharmacy depends on knowing the current balance and flows of stock issued in the past. It is therefore necessary to have the relevant information at the peripheral level. Data from the periphery cannot simply be regrouped at the central level. Many data will be missing and other considerations, such as modifications in treatment schedules or changes in pharmaceutical policy, need to be taken into consideration. Thus the central level must have its own information system that permits quantification. If there are depots at an intermediate level, that level must also have an information system.