Figure 6.

Simulated plasma colchicine concentrations (μg/l) versus time (h) for three levels (30%, 50%, and 70%) of clearance impairment. For each level of impairment, a newly proposed dosage regimen is utilised. (A) 30% impairment: 0.25 mg thrice daily, (B) 50% impairment: 0.25 mg twice daily, (C) 70% impairment: 0.25 mg twice daily for the first two days and then 0.25 mg once daily. Upper line: 3 μg/l, plasma concentration that elicits toxic effects. Lower line: 0.5 μg/l, minimum effective plasma concentration. The inter-individual variability values, considered for all pharmacokinetic parameters, were those reported in the study of Thomas et al. (1989). Dashed lines indicate the average peak and trough concentration values at steady state.