Presentation

As either a 1 ml glass vial containing 30 mg or as a premixed 10 ml syringe containing 30 mg. The contents of the glass vial should be mixed in a 10 ml syringe with normal saline to produce a final concentration of 3 mg/ml.

3-6 mg bolus doses are titrated to effect. Beyond a total dose of 30 mg, the effects become less pronounced.

Ephedrine acts indirectly by causing the release of noradrenaline at the sympathetic nerve terminals, which then stimulates adrenoceptors non-specifically. Tachyphylaxis is seen as a result of depletion of noradrenaline stores. Ephedrine also has a weak direct action on adrenoceptors.

Its activation of both alpha- and beta-adrenoceptors causes an increase in cardiac output and an increase in systemic vascular resistance, both of which improve the BP. The effects only last a few minutes.

Modest hypotension associated with a normal or slow heart rate.