Systemic absorption of inhaled epinephrine

To determine the systemic absorption of epinephrine when it is given by inhalation, six normal volunteers were given 15 puffs, followed by 30 puffs, of epinephrine from a pressurized aerosol (160 µg epinephrine/puff). The peak mean (±SE) plasma epinephrine levels were 1.50 (±0.61) and 4.22 (±1.93) nmol/L 1 minute after each dose, respectively. The effect on physiologic finger tremor correlated with the plasma epinephrine level and returned to baseline 20 minutes after taking the higher dose. There was a small fall in mean plasma potassium levels of 0.45 mmol/L and a small rise in plasma glucose levels of 0.81 mmol/L. On a separate occasion an injection of 0.3 ml of 1/1000 (300 µg) epinephrine was given subcutaneously to the same individuals. This caused a peak plasma epinephrine level of 2.43 (± 0.47) nmol/L at 10 minutes, and this was still raised at 2.05 (± 0.41) nmol/L after 40 minutes. The maximum fall in the mean plasma potassium level was 0.43 mmol/L after the injection. Clinical Pharmacology and Therapeutics (1986) 40 , 673–678; doi: 10.1038/clpt.1986.243