The consensus view that drugs in a CT should have matching half-lives [,]. (A) The constituent drugs have very different half-lives (as in the current generation of ACT) leaving the ‘blue’ drug to persist as a vulnerable monotherapy for an extended period of time post-treatment after the ‘red’ drug concentration has decayed to sub-therapeutic concentrations. (B) The constituent drugs have roughly similar half-lives meaning they should, in principle (but see main text), provide mutual protection post treatment. [Figure 1 was constructed using simple PK/PD models and their corresponding equations[26, 29]. Parameter values for the two drugs were as follows: Dose is 11 mg/kg; volume of distribution is150 L/kg. Elimination rates per day were 0.03 for ‘blue’ and 0.07 for ‘red’ (equivalent to half-lives of 23.1 and 9.9 days, respectively) in (A) changing to 0.032 for ‘red’ in (B) (equivalent to half-life of 21.7 days)].