alpha adrenergic agonists

introduction

generally refers to agonists of the alpha-1 adrenergic receptor
these agents cause vasoconstriction, tachycardia and generally increase cardiac output and blood pressure
thus they are commonly used as:
- inotropes
- vasopressors such as in Rx of anaphylaxis
- local vasoconstriction such as when used with local anaesthetic agents (eg. Co-Phenylcaine Forte Spray) or as vasoconstrictor nasal drops for the common cold
- nasal vasoconstrictors for rhinitis such as oral pseudoephedrine
- inhaled vasoconstriction such as adrenaline / epinephrine nebulisers for croup
excess doses may cause hypertension, acute pulmonary oedema (APO), acute coronary syndromes, cardiac arrhythmias, or gut and limb ischaemia with resultant lactic acidosis, particularly in susceptible patients such as those with hypertension, ischaemic heart disease (IHD) or peripheral vascular disease (PVD or PAD)
examples include:
- phenylephrine
- metaraminol (Aramine)
- adrenaline / epinephrine
- noradrenaline / norepinephrine
- ephedrine
- pseudoephedrine (Sudafed)
- midodrine