Every year, TB kills nearly two million people. With the poor access to adequate health services, including essential medicines, in many countries, the spread of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), and the emergence of multidrug-resistant tuberculosis (MDR-TB), greater efforts are urgently needed to combat the worsening impacts of TB. Estimates suggest that, in the absence of such efforts, every year between seven and eight million people will develop active TB. The economic costs of TB are tremendous and mostly affect the poor. The socioeconomic impact of the disease is greatest on adults in their most economically active years: three-quarters of the new cases of TB each year are among people aged between 15 and 54. The poor and marginalized in the developing world are the worst affected: 95% of all cases and 98% of deaths from TB occur in resource-poor countries.

Extending and maintaining regular access to effective TB treatment is clearly essential if patients are to be cured and drug resistance avoided. The expansion of DOTS strategy to control the TB epidemic has been identified as a high priority for WHO's Stop TB Initiative. DOTS consists of a five-component policy package (see Box 2, and section 2) which is acknowledged internationally as the most effective intervention for preventing and controlling TB.

Within the DOTS strategy, standardized short-course chemotherapy, promptly delivered, can have a major impact on TB morbidity and mortality. Since 1994 and especially since 1998, WHO and IUATLD have advocated replacing single-drug regimens for treatment of primary TB with fixed-dose combinations. Use of WHO recommended 3- and 4-drug FDC tablets has been promoted for the intensive phase of DOTS. The potential advantages of FDCs in treating TB include:

• simplicity of treatment with minimal prescription errors;

• increased patient acceptance and compliance with decreased likelihood of inadvertent medication errors;

• increased health worker compliance to standardized and correct treatment;

• improved drug management because ordering, procurement, distribution and dispensing/handling at different levels of the NTP are easier when there are fewer items with a single expiry date to deal with;

• lowered risk of misuse of single drugs and of emergence of drug-resistant TB due to reduced use of monotherapy.

This guide has been developed based on recommendations made at various meetings and consultations of experts in TB treatment, NTP managers, researchers, academics, drug regulatory authorities, and other concerned stakeholders.