EPHEDRINE

Actions • Sympathetic amine

• Stimulates both alpha & beta receptors

• Is active orally

• Slower onset of action & longer duration of action than adrenaline; used when prolonged action required

• Cardiovascular & bronchodilatory effects

Indications • Bronchospasm-asthma

• Pressor

• Nasal decongestant

Contraindication

• Severe cardiac disease

• Arrhythmias

• Hypertension

• MAOI [ephedrine acts indirectly to release NAd from peripheral nerve endings

METHOXAMINE

Actions • alpha selective adrenergic that acts as a vasoconstrictor

• Pharmacologically similar to phenylephrine

Indications • Used during anaesthesia to maintain BP and in the treatment of paroxysmal supraventricular tachycardia

• ?Used in Australia as a decongestant only

Adverse effects

• Hypertension, bradycardia, cardiac depression

PHENYLEPHRINE

Actions • Relatively pure alpha-agonist

• Much longer duration of action than catecholamines

Indications • Pressor

• Decongestant

• Mydriatic

Adverse effects

• Hypertension, arrhythmias