Efficacy, safety, and pharmacokinetics of MR13A11A, a generic of remifentanil, for pain management of Japanese patients in the intensive care unit: a double-blinded, fentanyl-controlled, randomized, non-inferiority phase 3 study

BACKGROUND

The aims of this study were to evaluate the efficacy, safety, and pharmacokinetics (PK) of continuous intravenous administration of remifentanil in mechanically ventilated patients in the intensive care unit (ICU).

METHODS

This was a multicenter, randomized, double-blinded, fentanyl-controlled, non-inferiority phase 3 study. Patients aged ≥ 20 years requiring 6 h to 10 days mechanical ventilation in an ICU and requiring pain relief were randomly assigned in a 1:1 ratio to receive either remifentanil (n = 98) or fentanyl (n = 98). Dose was titrated from an infusion rate of 1 mL/h (remifentanil: 0.025 µg/kg/min, fentanyl: 0.1 µg/kg/h) until the target level of analgesia (behavioral pain scale [BPS] ≤ 5 or numerical rating score [NRS] ≤ 3) was achieved by escalating the dose in 1 mL/h increasing. Administration was then adjusted to maintain the target level of analgesia until weaning from the ventilator. The primary endpoint was the proportion of patients who did not require rescue fentanyl. Safety was assessed according to standard procedures. PK of remifentanil in the arterial blood was assessed in 24 patients.

RESULTS

The proportion of patients achieving the primary endpoint in the remifentanil and fentanyl groups was 100% (92/92) and 97.8% (88/90), respectively. The difference between the groups was 2.2% (95% confidence interval, - 0.8-5.3) and non-inferiority of remifentanil to fentanyl was verified (p < 0.0001). The incidences of any adverse events in the remifentanil and fentanyl groups was 34 of 92 patients (37.0%) and 34 of 90 patients (37.8%), respectively. Adverse drug reactions was 12 in 92 patients (13.0%) and 15 in 90 patients (16.7%), respectively. In the PK analysis, blood remifentanil concentration decreased within 10 min to almost 50% of the end of administration, suggesting rapid offset of action following discontinuation of remifentanil.

CONCLUSIONS

Remifentanil can be used safely for pain management in mechanically ventilated Japanese patients in the ICU.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCT2080224954. Registered 20 November 2019, https://jrct.niph.go.jp/latest-detail/jRCT2080224954 .

The role of nuclear factor-kappa B in the regulation of endothelin-1 production by nitric oxide

Nitric oxide (NO) has been reported to have an inhibitory effect on endothelin-1 production, but the detailed mechanisms are poorly understood. Our previous studies showed that a transcription factor nuclear factor-kappaB (NF-kappaB) plays an important role in endothelin-1 production. In the present study, we investigated the possible involvement of NF-kappaB in the inhibitory regulation of endothelin-1 production by NO. 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (carboxy-PTIO), which is a well-known NO scavenger, remarkably increased both endothelin-1 production and NF-kappaB activation in cultured vascular endothelial cells. On the other hand, a spontaneous NO donor (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexanamide (FK409) significantly attenuated the basal and tumor necrosis factor-alpha-induced endothelin-1 production and NF-kappaB activation in endothelial cells. In addition, we found that FK409 suppressed NF-kappaB activation by the induction and stabilization of the inhibitory protein alpha, IkappaBalpha. Taken together, our results suggest that NO modulates the endothelial endothelin-1 production, possibly through the regulation of NF-kappaB activation.

Nitric oxide inhibits endothelin-1 production through the suppression of nuclear factor kappa B

We have reported previously that the nitric oxide (NO) donor FK409 [(+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexanamide] improved renal dysfunction as well as renal lesions in rats with ischaemia/reperfusion injury. We also found that FK409 substantially reduced endothelin-1 (ET-1) production in cultured vascular endothelial cells (ECs). Nuclear factor kappa B (NF-kappa B) is known to play a key role in the development of ischaemic disorders through regulation of the expression of a variety of genes. In the present study, we examined the effects of FK409 on ET-1 production in cultured pig aortic ECs, and the possible involvement of NF-kappa B in the inhibitory effect of NO on ET-1 production. FK409 significantly attenuated basal and tumour necrosis factor-alpha (TNF-alpha)-induced preproET-1 mRNA expression in ECs. In addition, FK409 diminished basal and TNF-alpha-stimulated NF-kappa B activation in ECs. Pretreatment with N-benzyloxycarbonyl-Ile-Glu(O-t-Bu)-Ala-leucinal or BAY 11-7082, both of which are suppressors of NF-kappa B activation, effectively attenuated basal and TNF-alpha-induced ET-1 mRNA expression. These findings suggest that the suppression of NF-kappa B activation is at least partly involved in the FK409-induced inhibition of ET-1 production in ECs. We propose that NF-kappa B activation plays an important role in ET-1 production.

A nuclear factor-kappaB inhibitor BAY 11-7082 suppresses endothelin-1 production in cultured vascular endothelial cells

BAY 11-7082, an inhibitor of nuclear factor-kappaB (NF-kappaB), which prevents a step of the phosphorylation of inhibitory protein IkappaB bound to NF-kappaB, suppressed basal and tumor necrosis factor (TNF)-alpha-induced prepro endothelin (ET)-1 mRNA expression and NF-kappaB activation in cultured vascular endothelial cells. BAY 11-7082 significantly decreased basal and TNF-alpha-induced ET-1 release from endothelial cells. These results indicate that the inhibition of NF-kappaB activation contributes to the suppressive effect of BAY 11-7082 on ET-1 gene expression and ET-1 release, thereby suggesting that NF-kappaB plays an important role in the regulation of ET-1 production.