Storage and Distribution of Essential Drugs and Vaccines
In the past, essential drugs, vaccines, and contraceptives were for the most part distributed using separate logistics systems. For vaccines and contraceptives, such systems were organized vertically to some extent, and because they were concerned with a far more limited range of products, the task was somewhat simpler.
A push has been made to integrate the distribution systems for drugs, vaccines, and contraceptives, although in most places separate systems are still operating, at least at the national level and often down to provincial levels. Vian and Bates (2003) noted a number of changes to the distribution systems in the past few years. In many countries, health sector reform programs included efforts to reform central medical stores to allow more autonomy and to introduce commercial incentives and improved management methods. In some cases, this reform has led to higher staff productivity, better performance, and more enforcement of payment policies. However, disruption in supply often occurs during central medical store transition phases. Increased integration of commodities, including contraceptives and vaccines, has also been noted. In some cases, it has decreased the amount and reliability of data collected on logistics, creating problems for needs estimation and for tracking of consumption (Vian and Bates 2003).
Another trend is the increasing use of private transporters and contracting out for transportation management; contracting transport can generate cost savings and improve services. Finally, a trend toward computerized systems exists, particularly involving the use of donor-financed software for improved management of logistics as well as a number of comprehensive assessment tools and indicator sets for evaluating drug supply systems. But the proliferation of software systems, with little coordination and not enough support and maintenance of complex and fragile computer systems, can be counterproductive, especially if paper-based systems that are difficult to reintroduce upon failure of the computer system are abandoned (Vian and Bates 2003).
Storage and Stocks Management
Drugs require secure storage in controlled climatic conditions and a reliable method of stock rotation. The FEFO rule (first expiry, first out) helps ensure that older stock is used up first. Security is another major consideration: access to the storehouse must be carefully controlled so that theft and embezzlement are minimized, and the persons who control access must themselves be trustworthy. Proper storage conditions, including minimizing exposure to heat, light, and humidity, are important for some drugs, but most drugs have proved remarkably resistant to poor conditions. Notable exceptions are tetracycline products, which become toxic when exposed to heat, and oxytocin and ergometrine, which lose their potency when exposed to light and heat; all should thus be stored in the refrigerator. The same applies to insulin and, of course, most vaccines. Correct FEFO stock rotation will ensure that exposure to harsh conditions is minimized and that potency is preserved as much as possible. Ensuring good air circulation and preventing direct water contact are most important.
Management of Donated Drugs
Management of donated drugs is a major problem in some areas, particularly if an emergency has precipitated an influx of drug donations. The best strategy is to accept only invited donations of drugs that the facility has specifically asked for (WHO 1999a). Any drug that is neither vital nor essential, that is not labeled clearly with its generic name, that is expired, that is in a package that contains only a few days' dosage, or that is not on the national essential drugs list or on the facility's formulary should be discarded—and the pharmacist should feel no guilt and fear no sanctions about disposing of such materials. They take up space, require tracking like other drugs, and present a risk of being accidentally dispensed to a patient and causing the patient harm—a factor that must also be taken into account. Proper disposal can be a problem. These drugs constitute potential toxic waste, and they should be treated as such and disposed of so that they cannot be retrieved and sold (WHO 1999b).
Vaccines are delicate products that are destroyed if handled incorrectly. Vaccine management involves the use and distribution of vaccines, from the manufacturers to the end users. Aspects of vaccine management include inventory and forecasting, stock control, in-country distribution, storage and handling, equipment replacement plans, procedures for the use of the vaccine, monitoring of vaccine storage, transport management, and operational management.
Forecasting of vaccine needs is the first building block of an adequate management system. In 2002, 22 of 82 countries surveyed by UNICEF indicated that they had experienced a vaccine stockout. In addition to lack of resources, the main reasons cited included poor or late forecasting.
In recent years, attention has focused on avoiding heat exposure. The introduction of costly vaccines that are sensitive to freezing has drawn attention to the need to protect vaccines from excessive exposure to cold as well as heat. WHO guidelines for the international transport of vaccines now include specific recommendations for each category of vaccine, including freeze sensitivity. National cold stores are the next critical level of the vaccine management system. A failure there—where vaccines are received, stored, and distributed in bulk—can result in extensive losses. The WHO-UNICEF Effective Cold Store Management Initiative encourages countries to procure equipment and adopt management and training practices that fully protect vaccines in national and intermediate vaccine stores.
At the country level, emphasis is being put on the use of new tools, such as the vaccine vial monitor. This heat-sensitive label is a time-temperature indicator used to ensure that the vaccines have not been damaged by excessive exposure to heat, to identify weaknesses in the cold chain, and to take vaccines beyond the cold chain to children who have no access to fixed health facilities.
Together with the increased use of vaccine vial monitors, the gradual adoption of the multidose vial policy contributes to the reduction of wastage. This policy of using opened multidose vials of vaccine in subsequent immunization sessions applies to all multidose vials of liquid vaccine containing thimerosal (WHO 2000). The policy was formulated in 1996 but its adoption remains limited.