Mean (SD) demographic, clinical, and biological characteristics at baseline for patients in this study, and pharmacokinetic parameters of total and free MTX
| Parameters | CLCR, ml/min | |||
|---|---|---|---|---|
| Group 1 <45 | Group 2 45–60 | Group 3 61–80 | Group 4 >80 | |
| Total no of patients | 7 F | 15 F | 8 M, 17 F | 8 M, 22 F |
| Age (y) | 76.4 (6.0) | 67.1 (5.8) | 65.5 (8.4) | 52.8 (10.9) |
| Weight (kg) | 53.3 (8.5) | 54.6 (6.5) | 65.6 (11.8) | 71.1 (14.9) |
| Duration of disease (months) | 144 (99) | 210 (189) | 172 (107) | 143 (92) |
| Duration of MTX treatment (months) | 39.3 (40.4) | 52.3 (35.7) | 54.6 (20.6) | 52.0 (24.7) |
| Number of swollen joints | 5.43 (3.05) | 7.87 (5.13) | 4.8 (6.0) | 10.4 (18.3) |
| Ritchie’s articular index | 22.4 (39.8) | 10.5 (10.5) | 8.1 (11.6) | 8.2 (7.4) |
| CRP (mg/l) | 19.1 (16.2) | 20.7 (20.5) | 17.4 (19.6) | 20.5 (28.3) |
| ESR (mm 1st h)** | 49.1 (23.5) | 34.1 (21.1) | 23.2 (17.7) | 22.9 (17.1) |
| CLCR (ml/min) | 39.8 (4.4) | 55.8 (3.7) | 68.1 (5.2) | 103.5 (20.3) |
| Extend of unbound fraction (%) | 54.1 (7.5) | 59.8 (7.9) | 58.5 (6.05) | 57.4 (7.3) |
| Free MTX | ||||
| MTX concentration (t=2h) (μM2-151) | 0.34 (0.088) | 0.28 (0.077) | 0.25 (0.059) | 0.24 (0.08) |
| MTX concentration (t=8h) (μM2-151) | 0.11 (0.058) | 0.074 (0.027) | 0.075 (0.026) | 0.064 (0.023) |
| T1/2elimination (h) | 22.7 (9.1) | 13.7 (3.2) | 12.0 (3.3) | 11.5 (3.2) |
| CLfu (ml/min) | 118.5 (35.1) | 162.8 (45.3) | 171.1 (34.0) | 206.0 (44.5) |
| Total MTX | ||||
| MTX concentration (t=2h) (μM2-151)** | 0.66 (0.18) | 0.51 (0.13) | 0.49 (0.11) | 0.45 (0.12) |
| MTX concentration (t=8h) (μM2-151)*** | 0.21 (0.12) | 0.13 (0.052) | 0.12 (0.039) | 0.11 (0.04) |
| T1/2 elimination (h)*** | 22.7 (9.8) | 13.1 (2.9) | 11.9 (2.6) | 10.8 (3.3) |
| CLtotal(ml/min)*** | 63.7 (20.3) | 92.1 (23.8) | 95.7 (17.1) | 115.1 (19.9) |
| Vd (l/kg) | 2.16 (0.58) | 1.92 (0.49) | 1.61 (0.63) | 1.56 (0.57) |
↵2-151 Normalised to a 10 mg dose; one way ANOVA. **p<0.01,***p<0.001.