Systemic absorption of epinephrine compared between the intranasal and intramuscular routes of administration in healthy adults.

The systemic absorption of IN epinephrine 5 mg was significantly different from the control IN saline and about 0.5-fold that of IM epinephrine 0.3 mg. Although epinephrine administration via the less invasive IN route is safe and feasible, further investigations are necessary to achieve an adequate and consistent systemic absorption comparable to that of the conventional IM injection.