EXAMPLES
Noradrenaline, ephedrine, phenylephrine
MECHANISM OF ACTION
- Stimulation of peripheral a-adrenoceptors within the vasculature, leading to vasoconstriction and increased systolic and diastolic blood pressure.
INDICATIONS
- Acute hypotension.
- Cardiac arrest.
CAUTIONS AND CONTRA-INDICATIONS
- Hypertension
SIDE-EFFECTS
- Hypertension.
- Headache.
- Arrhythmias.
- Bradycardia/tachycardia.
METABOLISM AND HALF-LIFE
- Metabolised in the liver and other tissues by MAO and COMT.
MONITORING
- Continuous cardiac monitoring in a high-dependency area is required.
- Monitoring of oxygen saturation, urine output and renal function is also necessary.
DRUG INTERACTIONS
- Severe, prolonged hypertension when given in combination with MAOIs.
IMPORTANT POINTS
- Ephedrine can be used to treat hypotension resulting from spinal/epidural anaesthesia.