Table 2.
Summary of caffeine citrate doses and concentration by site
| Site 1 (N=100) |
Site 2 (N=108) |
Site 3 (N=107) |
Site 4 (N=95) |
Total (N=410) |
|
|---|---|---|---|---|---|
| Postnatal age at start of caffeine (days) | 1 (0–1) | 0 (0–0) | 0 (0–1) | 0 (0–1) | 0 (0–1) |
| Loading dose day 1 (mg/kg/day) | 20 (19–22) | 17 (13–25) | 20 (20–25) | 20 (20–20) | 20 (19–23) |
| Daily maintenance dose (mg/kg/day)a | 9 (8–10) | 7 (5–10) | 5 (5–6) | 9 (8–10) | 8 (5–10) |
| Maximum daily dose (mg/kg/day) | 20 (12–24) | 11 (8–19) | 13 (10–15) | 19 (17–20) | 16 (10–20) |
| Cumulative dose (mg/kg) | 666 (584–852) | 380 (295–517) | 263 (201–333) | 538 (412–718) | 455 (292–640) |
| Duration of treatment (days) | 77 (62–97) | 55 (45–65) | 52 (35–64) | 63 (51–80) | 60 (46–75) |
| Site 1 (N=24) |
Site 2 (N=3) |
Site 3 (N=101) |
Site 4 (N=46) |
Total (N=174) |
|
| Average plasma concentration (mg/L)b | 26 (22–30) | 24 (22–26) | 16 (14–18) | 24 (18–29) | 18 (15–24) |
| Maximum plasma concentration (mg/L) | 29 (26–33) | 24 (22–26) | 24 (21–27) | 27 (18–35) | 25 (21–29) |
| Postnatal age at first collection (days) | 21 (15–38) | 40 (38–43) | 4 (3–6) | 22 (17–31) | 7 (4–20) |
Data presented as median (IQR) in cohort; individual variables represent summary statistics per participant.
Multiple doses administered in a calendar day were combined as the daily dose.
a
For each participant, maintenance dose was defined as the average of all caffeine doses after loading dose day 1.
b
For each participant, average plasma concentration was defined as the average of all available plasma concentrations.