Systemic absorption of adrenaline after aerosol, eye-drop and subcutaneous administration to healthy volunteers

Abstract

Adrenaline is the drug of choice for management of the anaphylactic reaction. The objective of this study was to compare systemic absorption of adrenaline after administration by different routes to healthy volunteers. Ten puffs (1.5 mg as adrenaline base) with 10-15 s intervals between them followed 2 h later by 20 puffs (3 mg) of adrenaline from a pressurized aerosol (Medihaler-Epi, 3M Riker, 14.0 mg/ml adrenaline acid tartrate) were sprayed into the cheek pouch or inhaled through the mouth or the nostrils. Adrenaline was also administered to the eyes by giving 2 drops (1 mg) of Isopto-Epinal (Alcon, 10 mg X ml-1). Finally, 0.5 ml (0.5 mg) of adrenaline was given subcutaneously in the upper arm of the same individuals. The systemic absorption was determined by measuring plasma adrenaline levels and effects on blood pressure, heart rate and finger tremor before and 5, 15, 30, 60, 90, and 120 min after adrenaline administration. Adrenaline given as eye-drops did not have any significant effect on these parameters. Subcutaneously administered adrenaline caused within 5 min a significant increase of plasma adrenaline level (from 1.0 +/- 0.2 to peak of 6.5 +/- 1.2 nM) which gradually decreased during 2 h. This mode of adrenaline administration increased the systolic blood pressure by a maximum of 11 +/- 3.5 mmHg, heart rate by 9 +/- 2.2 beats X min-1, tremor ratio by 4 +/- 0.6 and reduced the diastolic blood pressure by 18 +/- 4.7 mmHg. The cardiovascular effects were approximately maximum 15 min after administration and lasted almost 90 min.(ABSTRACT TRUNCATED AT 250 WORDS)