Table 2. Number and percentage of participants who experienced apnea that required stimulation (i.e. persistent apnea).
| Part A: Healthy Volunteers | Part B: Opioid-tolerant Patients | |||||||
|---|---|---|---|---|---|---|---|---|
| Fentanyl Dose | Fentanyl Dose Number | Placebo for 0.2 ng/mL (N = 6) | Buprenorphine 0.2 ng/mL (N = 6) | Placebo for 0.5 ng/mL (N = 6) | Buprenorphine 0.5 ng/mL (N = 6) | Fentanyl Dose Number | Placebo (N = 8) | Buprenorphinea (N = 8) |
| 0.075 mg/70 kg | 1 | 0/6 (0) | 0/6 (0) | 0/6 (0) | 0/6 (0) | |||
| 0.15 mg/70 kg | 2 | 1/6 (17) | 0/4 (0) b | 0/6 (0) | 0/6 (0) | |||
| 0.25 mg/70 kg | 3 | 2/2 (100)b | 2/4 (50) | 3/4 (75)b | 1/6 (17) | 1 | 0/8 (0) | 0/8 (0) |
| 0.35 mg/70 kg | 4 | 0/0 | 0/0b | 0/0b | 0/1 (0)b | 2 | 2/8 (25) | 0/8 (0) |
| 0.50 mg/70 kg | 3 | 1/6 (17) | 0/8 (0) | |||||
| 0.70 mg/70 kg | 4 | 3/4 (75)b | 0/8 (0) | |||||
aThe three buprenorphine dose groups in opioid-tolerant patients (target plasma concentrations of 1, 2 and 5 ng/mL) were grouped for this analysis.
bSome participants did not receive some fentanyl doses due to adverse events, apnea events that did not require stimulation or abnormalities in other ventilatory parameters (i.e. unstable breathing, drop in ventilation or saturation and high end-tidal CO2).