Meds exam 3 Flashcards
Amiodarone: Classification, action, indications
Antiarrhythmic
Predominantly Class III antiarrhythmic (blocks K+ channels, lengthens absolute refractory period)
But has Class I (blocks Na channels), II (beta blocker), and IV actions (blocks Ca++ channels and vasodilates)
Indicated for: Atrial arrhythmias (for rhythm control), VT, VF
Amiodarone: Dose
Loading infusion: 1000mg in 24hrs
Bolus: 150mg in 100cc D5W over 10 mins
followed by continuous infusion 1mg/min for 6 hrs
then maintenance infusion 0.5mg/min
USE IN-LINE filter, central line preferred
Amiodarone: Nursing considerations
May cause lengthening QT and Torsades
Monitor hypotension and bradycardia
Long term use can cause pulmonary toxicity, lover damage, thyroid damage.
Half life is long 15-142 days
Lasix: Class, action, indications
Loop diuretic
Inhibits Na-K-2Cl transporter in the ascending LOH, results in excretion of Na+, K+, Cl- AND H2O
Used for fluid overload, pulmonary edema, CHF, LV failure, renal failure
Lasix: Dose
Bolus 20-40mg IV
Higher doses needed for pts in renal failure
Continuous infusion: 100mg/100cc @ 1-4mg/hr
Onset 5 mins, peak 20-60minss, duration 2 hrs
Lasix: Considerations
Give slowly as increased push rate causes loss of hearing and tinnitus
Monitor hypotension, serum lytes especially K+
Chronic use of lasix causes metabolic alkalosis (hypochloremic alkalosis)
MgSO4: Class, action, indications
Electrolyte, anticonvulsant, laxative
Important in enzyme reactions, nerve conduction, cardiac electrophys, muscle contraction
Indicated for hypomagnesemia, treatment for torsades de pointes, “cardiac protection”, seizure, hypothermia protocols used for cooling
MgSO4: Dose and nursing considerations
1-2g in 100cc over 1 hr
Side effects: Bradycardia, hypotension
If Mg is corrected first, other electrolytes are more easily corrected
Mannitol: Class, action, indications
Osmotic diuretic, available as 10% or 20%
Hypertonic fluid resulting in shift of fluid from intracellular to extracellular and intravascular compartments. Requires intact blood-brain barrier.
Renally, prevents Na, Cl reabsorption in ascending loop due to hypertonic, increase osmotic pressure of glomerular filtrate increases U/O
indications: Acute elevations in ICP, cerebral herniation
Mannitol: Dose
For ICP: 0.25 - 1g/kg rapid infusion over 20-30mins, may be repeated q6-8hr
Onset 15 mins, duration 3-8 hrs
CENTRAL LINE preferred
Mannitol: Considerations
May cause:
Hypovolemia
Electrolyte imbalances (Na, K)
Pulmonary edema (fluid overload)
Maintain serum osmolality < 320 osmoles. Higher than that can cause DEMYELINATION SYNDROME
Excessive use break down BBB leading to increased ICP. Monitor renal function, large dose can cause renal failure
KCL: Class, action, indications, dose
Ion/electrolyte, used in cardiac electrical activity, nerve and muscle conduction, acid base balance
KCL used for hypokalemia (normal K+ is 3.5 - 5.5 meq/L)
For cardiac pts, K should be optimized to > 4
Dose: 20-40 mmol in 100cc over 1 hr via CENTRAL LINE
Sometimes OK to give 20mmol in 50cc over 1 hr via LARGE peripheral
Must use infusion pump and premixed bags
KCL: Nursing considerations
ECG monitoring required
Caution in pts with renal impairment
What causes hypokalemia?
Transcellular shifts:
Beta 2 agonists, insulin
Losses:
Diuretics, NG suction, vomiting, diarrhea, corticosteroids increase K+ excretion
What are signs of hypokalemia?
PACs, PVCs, arrhythmias, flat or inverted T waves, lengthened QT