Adrenaline
| Net effect | +ve inotrope (inodilator) , +ve chronotrope maintains cerebral and coronary blood flow |
|---|---|
| Metabolism | COMT and MAO to VMA |
| Elimination | Renal |
| Time course of action | Rapid onset - Onset of action 1-2 minutes - Half-life 5 minutes - Duration of action 2-10 minutes |
| Mechanism | alpha-1 receptor agonist + beta agonist - more beta effects at low dose (+ve inotropy/chronotropy, skeletal muscle vasodilation) - more alpha effects at high dose (peripheral vasoconstriction) |
| Adverse effects | pro-arrhythmogenic → see below |
↑ Na/K ATPase activity →
- hypokalaemia with rebound hyperkalaemia once adrenaline is stopped
- ↑ lactate
arrythmogenic effects
- ↓ K
- ↑ activity of ectopic pacemakers
- QT prolongation at high doses
- ↑ early afterdepolarisation and later afterdepolarisation
Caution in...
- HOCM and any ventricular outflow obstruction:
- ↑ contractility = ↑ obstruction and ↓ cardiac output
See also Inotropes
dilutions - a great source of drug errors
- 1:1000 for IM - Anaphylaxis (bolus 0.5ml max)
- 1:10000 for IV in cardiac arrest context = 0.1mg/ml
- ALS bolus dose = 10ml = 1mg
- Anaesthetic bolus dose - dilute 1:10 (1ml of 1:10000 + 9ml 0.9% NaCl), 1ml at a time
- 80 mcg/ml in ICU infusions
- 0.01-0.3mcg/kg/min