EXAMPLES
Adrenaline, dopamine, dobutamine, isoprenaline
MECHANISM OF ACTION
- Actions vary depending on which receptors are stimulated.
- Adrenalineactsona-(peripheral vasculature)and-adrenoceptors(myocardium), producing positive inotropic and chronotropic effects.
- Low-dose dopamine and dobutamine stimulate b1-adrenoceptors in the myocardium, predominantly increasing contractility.
INDICATIONS
- Cardiogenic shock.
- Septic shock.
- Acute hypotension.
- Cardiac arrest (adrenaline)
CAUTIONS AND CONTRA-INDICATIONS
- Phaeochromocytoma (dopamine).
- Atrial and ventricular tachyarrhythmias (dobutamine)
SIDE-EFFECTS
- Nausea and vomiting.
- Hypotension/hypertension .
- Peripheral vasoconstriction.
- Tachycardia
METABOLISM AND HALF-LIFE
- Metabolised by the liver, kidney or plasma MAO and COMT; t½ 2min.
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.
- Adrenaline should not be used with other sympathomimetic agents due to the additive effect.
- Hypertensive crisis when given in combination with MAOIs.
- Hypertension and reflex bradycardia when given in combination with b blockers
IMPORTANT POINTS.
- In patients with septic or haemorrhagic shock, the volume must be replaced (though this may worsen cardiogenic shock), after which sympathomimetics may be required to improve cardiac output.
- Often used in the intensive care setting to maintain perfusion to vital organs. Adrenaline is used as part of the Resuscitation Council UK guidelines