University:
West Coast University
Course:
PHAR 840 | Immunologic Conditions and Special Populations
Academic year:

2024
Views:

428

Pages:

48
Author:

Asal A.

Critical Care: Medication Selection, Dosing, Monitoring, and OKMA Safety 3 WEST COAST UNIVERSITY DEPARTMENT OF PHARMACY SPRING 2025 VLADIMIR YURUKOV, PHARMD, BCPS, APH Objectives Review functions of the sympathetic nervous system Discuss indications, dosing, adverse effects, and administration of the following classes of medications: › Vasopressors › Inotropes Antihypertensives Antiarrhythmics Sedation Insulin Please note that shortages may impact availability of medications and concentrations discussed Inotropes Indication - cardiogenic shock Used in both chronic and acute heart failure and occasionally in septic shock Patients may be on home infusions of dobutamine or milrinone Patients should be switched to hospital supply when admitted › Known to increase mortality in heart failure Used as palliative treatment or bridge to transplant/left ventricular assist device Increase myocardial contractility and heart rate to increase cardiac output Dobutamine Actions Positive inotrope and chronotrope Mild vasodilator due to effects on B2c Usual dosage 2.5-15 mcg/kg/min Do not titrate unless specified in order Timing Onset: 2-5 minutes Duration: 5-10 minutes Adverse effects Arrhythmias, tachycardia How supplied Premade concentrations: 500 mg/250 ml and 1000 mg/250 ml 500 mg/250 mL: central line preferred 1000 mg/250 ml central line required Milrinone Actions Positive inotrope (less effect on heart rate) Vasodilator (peripheral and pulmonary): May be used for pulmonary hypertension Usual dosage 0.063-0.75 mcg/kg/min Do not titrate unless specified in order Timing Onset: 10-15 minutes Duration: 3-4 hours Adverse effects Arrhythmias, hypotension Mav accumulate in renal dysfunction How supplied Standard concentration: 20 mg/100 mL May be given via central line or peripheral line Digoxin Indications Atrial fibrillation, heart failure Actions Weak positive inotrope Negative.chronotrope Usual dosage Weight-based loading dose Maintenance dose: 0.125-0.25mg daily or every other day: Dose adjusted based on renal function Timing Onset: minimum of 60 minutes Adverse effects Early foxicity-loss of appetite fatigue, nauseo, vomiting, yellow green color vision distortion Late foxcity-armyttimias bradycardia How supplied PO or Slow IV Push (over 5 minutes) Self Test True or False? Dobutamine 1000 mg/250 mL can be given peripherally. False Patients may continue their home supply of inotropes when admitted. False Milrinone should be used with caution in renal failure. The risk of digoxin toxicity is increased in hypokalemia. Vasopressors Norepinephrine Actions Weak inotrope Positive chronotrope Increases MAP and SVR Usual dosage 0.01-3 mcg/kg/min Central line administration strongly preferred! Titrate in 0.01-0.05 mcg/kg/min increments (order specific) May be used peripherally in emergent situations and requires central access within 4 hours How supplied Standard concentrations: 8 mg/250 ml and 16 mg/250 mL Epinephrine Actions Positive chronotrope and inotrope Increases MAP and SVR Usual dosage 0.01-0.5 mcg/kg/min Titratable orders: titrate in increments of 0.05 mcg/kg/min Some arders may specify not to titrate Central line administration preferred How supplied Standard concentrations: 5 mg/250 ml and 10 mg/250 mL Note Often not a first line vasopressor due to risk of increased lactate levels. Sympathetic Receptors Alpha 1 receptors (a1) Located in heart and blood vessels ↑ Contractility ↑ Vasoconstriction Dopaminergic Located in vascular smooth muscle Renal, coronary, cerebral, splanchnic ↑ Vasodilation Beta 1 receptors (β1) Located in heart ↑ Heart rate ↑ Contractility ↑ Rate of conduction Beta 2 receptors (B2) Located in bronchial and GI smooth muscle and blood vessels ↑ Vasodilation Bronchodilation Relaxation of Gl smooth muscle Phenylephrine Actions Increases MAP and SVR with little effect on HR Useful when tachycardia limits use of other pressors Usual dosage 0.5-9 mcg/kg/min Titrate in increments of 0.25 mcg/kg/min or 0.5 mcg/kg/min (order specific) Central line strongly preferred May use large peripheral for up to 4 hours How supplied Standard concentrations: 25 mg/250 mL, 50 mg/250 mL Vasopressin Actions Increases SVR and MAP Often used as 2nd line pressor to decrease norepinephrine requirements Usual dosage Normal dosage: 0.04 units/min Should not be titrated when used for septic shock Higher doses cause constriction of coronary arteries Central line only! How supplied Standard concentrations: 20 units/100 mL, 100 units/100 mL Dopamine Actions Positive chronotrope and inotrope at higher doses Usual dosage 5-30 mcg/kg/min Titrate in 1 mcg/kg/min to 2 mcg/kg/min increments (order specific) Central line preferred 400 mg/250 ml. concentration available in crash carts and can be given via peripheral access until central access obtained How supplied Standard concentrations: 400 mg/250 mL and 800 mg/250 mL