Argipressin

In this multicenter randomized trial (VASST) of 778 patients with septic shock, low-dose vasopressin (0.01-0.03 U/min) added to open-label catecholamines did not reduce 28-day mortality compared with norepinephrine (35.4% vs 39.3%, P=0.26) or 90-day mortality. A prespecified stratified analysis suggested vasopressin may be beneficial in the less-severe shock stratum (mortality 26.5% vs 35.7%, P=0.05), though the test for heterogeneity between strata was not significant. Serious adverse event rates were similar between groups.

This large study compared vasopressin with the standard drug norepinephrine in patients whose blood pressure had collapsed from severe infection (septic shock). Adding low-dose vasopressin was just as safe as norepinephrine but did not improve overall survival at 28 days. Patients with less severe shock appeared to possibly do better on vasopressin, but this was only a hint and not a definitive result.

This 2x2 factorial, double-blind RCT (VANISH) randomized 409 patients with septic shock to early vasopressin vs norepinephrine (and to hydrocortisone vs placebo) as first-line vasopressor. There was no significant difference in the primary outcome of kidney failure-free days between vasopressin and norepinephrine groups, though the confidence interval included a potentially important benefit. Fewer patients in the vasopressin group required renal replacement therapy (25.4% vs 35.3%; difference -9.9%), but 28-day mortality did not differ.

This trial tested whether starting vasopressin first (instead of the usual norepinephrine) protects the kidneys in patients with septic shock. Using vasopressin did not clearly increase the number of days patients were free of kidney failure, and survival was similar. However, fewer vasopressin-treated patients needed dialysis, hinting at a possible kidney benefit that needs further study.

In this multicenter double-blind RCT of 1,186 adults with out-of-hospital cardiac arrest, two injections of vasopressin (40 IU) were compared with epinephrine (1 mg) for resuscitation. There were no overall differences between vasopressin and epinephrine in rates of hospital admission or survival to discharge across the whole cohort or in the ventricular fibrillation and pulseless electrical activity subgroups. In the asystole subgroup, vasopressin was associated with higher rates of hospital admission (29.0% vs 20.3%, P=0.02) and survival to discharge (4.7% vs 1.5%, P=0.04), and in refractory arrest additional epinephrine after vasopressin improved outcomes.

This study compared vasopressin with the standard drug epinephrine (adrenaline) in people whose hearts had stopped outside the hospital. Overall, the two drugs worked about equally well for restarting the heart and survival. Vasopressin appeared to help more in patients with 'asystole' (a flatline rhythm), but for most patients neither drug was clearly better than the other.