Determination of fluctuation intravenous bolus administration

Fluctuation (O) is simply a measure of the magnitude of variation in, or the differences between, the peak and trough plasma concentrations at steady state or, by some definitions, the peak and average plasma concentrations at steady state. 

Fluctuation, therefore, is simply a measure of the ratio of the steady-state peak or maximum plasma concentration to the steady-state minimum or trough plasma concentration of a drug or the ratio of the peak or maximum steady-state concentration to the average plasma concentration at steady state for the chosen dosage regimen. 

The observed or calculated fluctuation for a dosage regimen of a drug also depends solely on the chosen dosing interval and, like drug accumulation, it is also expressed by using the concept of a numerical value. 

A high fluctuation value indicates that the ratio of the steady-state peak or maximum concentration to the trough or minimum concentration is large. Conversely, a low fluctuation value suggests that the ratio of these concentrations is small. Ideally, it is preferable to have a smaller ratio (i.e. smaller value) of maximum to minimum concentration at steady state, as illustrated in Fig. 11.10. 

By comparison of maximum concentration with minimum concentration at steady state 

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