Table 4.
Pharmacokinetic non-compartmental results of isoniazid in fast and slow acetylators
| Isoniazid | SLOW | FAST | % difference |
|---|---|---|---|
| Number of patients enrolleda | 28 | 64 | |
| Body Weight (median kg - range) | 10.0 (4.5–26.0) | 13.0 (4.4–44.0) | |
| Age (median months - range) | 36 (6–180) | 42 (2–180) | |
| Dosage (mean - % CV) | 4.82 (11.7) | 4.70 (13.3) | p-value: > 0.05b |
| CMAX (ug/mL) | 4.56 | 4.62 | −1.3 |
| TMAX (hr) | 1 | 2 | −50 |
| CL/F (L/hr) | 2.28 | 2.47 | −7.69 |
| CL/F/BW (L/hr/kg) | 0.23 | 0.19 | 21.1 |
| V/F (L) | 12.2 | 7.05 | 72.3 |
| V/F/BW (L/kg) | 1.21 | 0.54 | 124 |
| T1/2 (hr) | 3.69 | 1.98 | 86.4 |
| AUC0-∞ (hr × ug/mL) | 21.9 | 22.8 | −3.78 |
| AUC0-∞/dosage (hr × ug/mL/(mg/kg)) | 4.38 | 4.95 | −11.5 |
| T > MIC (hr) | 14.8 | 11.9 | 24.7 |
| T > MIC/24 h (%) | 61.7 | 49.4 | 24.8 |
| AUC0–24 h > MIC (hr × ug/mL) | 17.7 | 19.8 | −10.7 |
aAcetylator genotype was determined in 92 patients. bMann–Whitney T-test. Apart for dosage with mean and % CV, all values are reported as median (range) or as median estimates for pharmacokinetic parameters. C MAX maximum observed plasma concentration after oral administration, T MAX observed time to reach CMAX, CL/F oral elimination clearance, CL/F/BW elimination clearance corrected by the median body weight, V/F apparent volume of distribution, V/F/BW apparent volume of distribution corrected by the median body weight, T 1/2 terminal elimination half-life, AUC 0-∞ predicted area under the plasma concentration-time curve after the last dose from zero time to infinity, T > MIC time above the minimum inhibitory concentration, T > MIC/24 h percentage of the time above the minimum inhibitory concentration over the 24 h dose interval, AUC > MIC observed area under the plasma concentration-time curve above the minimum inhibitory concentration. % difference is calculated with the > 4 years group used as the reference