Effects of Intramuscular Vasopressin on Pharmacokinetics and Pharmacodynamics in Healthy Neonatal Piglets: A Dose-Response Study.

BACKGROUND

Neonatal resuscitation guidelines recommend the use of the vasopressor epinephrine during neonatal cardiopulmonary resuscitation (CPR); however, vasopressin may be a potential alternative. Successful neonatal CPR requires rapid vasopressor administration, but the current guideline-recommended routes can take several minutes to establish and require substantial skill and/or training. The intramuscular (IM) route provides rapid drug administration and does not require special skills, training, or equipment.

OBJECTIVE

We aimed to compare two doses of IM vasopressin to intravenous (IV) vasopressin in a healthy neonatal piglet model to examine the hemodynamic and pharmacokinetic effects.

METHODS

Fifteen neonatal piglets (n = 5/group; 1-3 days of age) were anesthetized, intubated via a tracheostomy, and randomized to 4 IU/kg IM vasopressin, 8 IU/kg IM vasopressin, or 0.4 IU/kg IV vasopressin. Various hemodynamic and cardiac function parameters were continuously recorded throughout the experiment. Blood was collected prior to drug administration and throughout the experiment for pharmacokinetic and pharmacodynamic analysis.

RESULTS

The 4 IU/kg IM vasopressin dose was ineffective in producing systemic changes in hemodynamics or cardiac function as it was poorly absorbed. The 8 IU/kg IM vasopressin dose had comparable results to IV vasopressin and was rapidly distributed to systemic circulation.

CONCLUSIONS

The higher IM vasopressin dose of 8 IU/kg is effective in increasing systolic and diastolic blood pressure.