Use of 2-, 3- and 4-drug FDCs does not replace proper case management and directly observed treatment (DOT), which ensure adherence to treatment and ultimately the cure of a patient.

In some countries, the use of 4-drug FDC tablets might not (yet) be allowed by the DRAs for various reasons, e.g. they may not yet be registered or licensed for marketing.

Besides the potential advantages described above (section 1.3), FDC tablets will contribute tremendously to DOTS expansion in several ways:

• there will be no more monotherapy with one medicine or an insufficient number of different loose drugs, reducing the chance of development of resistant strains of TB;

• the 4-drug FDC regimen decreases the risk of treatment failure and relapse;

• patients will have fewer tablets to swallow, which will help improve compliance;

• having fewer tablets to handle, supervision of drug intake will be quicker, so greatly reducing the workload and potential prescription errors of health workers administering DOTS;

• drug ordering, storage and stock control will be simpler and time will be saved, while errors are less likely to occur (fewer items to handle with the same expiry date);

• from the programme management point of view, calculation of drug needs, procurement, distribution and stocking throughout the programme will become simpler and, in some instances, even cheaper (e.g. due to less volume and storage capacity needed); and

• it will be easier to adjust dosages by body weight (see Tables 4 and 5).