VASOACTIVE DRUGS

Question 1

· Ephedrine

Answer 1

o Dose Range: 5-10 mg push IV (up to 50 mg); not used for continuous IV
o Concentration: 50mg diluted with 9 mL for 5 mg/mL conc
o Onset: Immediate
o ½ Life: 3 hours; duration of 60 minutes
o C/I: Avoid using in pt’s taking MAOIs
o Precautions: Tachyphylaxis at 50 mgs (you’ll add another pressor by this time), do not overtreat HoTN, doesn’t work well when neuronal catecholamine stores are depleted (sepsis) or absent (heart transplant)

Question 2

· Phenylephrine (#1 pressor given)

Answer 2

o Dose Range: 50-100 mcg push IV at a time; 20-50 mcg/min gtt
o Concentration: 100 mcg/mL premade stick; gtt 10mg/250mL = 40 mcg/mL
o Onset: 10-15 minutes
o ½ Life: 2.5 hours; duration of 15 minutes
C/I: Avoid in cardiogenic shock or HF
o Precautions: Watch for reflex bradycardia especially in younger pts (more vagal tone)!!

Question 3

· Epinephrine

Answer 3

o Dose Range: 5-10 mcg push IV; 1-20 mcg/min IV infusion (70kg pt)
o Concentration: 1mg/mL vial; dilute 1mg in 100mL= 10mcg/mL
o Onset: 1 minute onset; 5 minute duration
o ½ Life: 2 hours
o C/I: pts on MAOIs
o Precautions: HTN, nothing d/t emergent need
10 mcg epinephrine similar to 10 mg of ephedrine.

Question 4

Vasopressin

Answer 4

-Bolus dose: 1 unit IV bolus (works fast and large increase in BP)
-Maintenance dose: 0.01-0.04 units/min IV
o Concentration: 20 units in 10mL = 2u/mL
o Onset: rapid onset; 15 minutes pressor activity peak, 20 min DOA
o ½ Life: 30 minutes
o C/I: Use as resuscitory effort solely
o Precautions: If pt has HF and unable to take workload of fluid and vasoconstriction