Table 1 Comparison of growth and pharmacodynamic killing kinetics for planktonic (extracellular liquid culture) and intracellular (macrophage) M. tuberculosis.

From: Pharmacokinetic-Pharmacodynamic modelling of intracellular Mycobacterium tuberculosis growth and kill rates is predictive of clinical treatment duration

Treatment

Parameter

Macrophage (intracellular Mtb)

Liquid* (extracellular Mtb)

Control

Kg max (h−1) (D.Time)

0.033 (21.0 h)

0.0769–0.045 (9.0 h)

Rifampicin

Emax (h−1)

0.055

0.178

EC50 (ng/mL)

18.4

5.60

Ethambutol

Emax (h−1)

0.053

0.142

EC50 (ng/mL)

79.5

264

Isoniazid

Emax (h−1)

0.041

0.710, 0.055

EC50 (ng/mL)

32.1

790

Pyrazinamide

Emax (h−1)

0.043

NA

EC50 (ng/mL)

45.5

NA

  1. Kg max represents the maximal growth rate, E max represents the maximal possible kill rate and EC50 the concentration required to achieve 50% of the E max rate of kill. Parameters were derived from data generated from multiple independent experiments (n ≥ 3) performed in triplicate. NA, Not applicable. *For comparison, extracellular PD parameters based on in house and published values24, 25.
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