Meds exam 3

Question 1

Amiodarone: Classification, action, indications

Answer 1

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

Question 2

Amiodarone: Dose

Answer 2

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

Question 3

Amiodarone: Nursing considerations

Answer 3

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

Question 4

Lasix: Class, action, indications

Answer 4

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

Question 5

Lasix: Dose

Answer 5

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

Question 6

Lasix: Considerations

Answer 6

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)

Question 7

MgSO4: Class, action, indications

Answer 7

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

Question 8

MgSO4: Dose and nursing considerations

Answer 8

1-2g in 100cc over 1 hr

Side effects: Bradycardia, hypotension
If Mg is corrected first, other electrolytes are more easily corrected

Question 9

Mannitol: Class, action, indications

Answer 9

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

Question 10

Mannitol: Dose

Answer 10

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

Question 11

Mannitol: Considerations

Answer 11

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

Question 12

KCL: Class, action, indications, dose

Answer 12

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

Question 13

KCL: Nursing considerations

Answer 13

ECG monitoring required

Caution in pts with renal impairment

Question 14

What causes hypokalemia?

Answer 14

Transcellular shifts:
Beta 2 agonists, insulin

Losses:
Diuretics, NG suction, vomiting, diarrhea, corticosteroids increase K+ excretion

Question 15

What are signs of hypokalemia?

Answer 15

PACs, PVCs, arrhythmias, flat or inverted T waves, lengthened QT

Question 16

Sodium bicarb: Class, action

Answer 16

Alkalizing agent, base

Binds with H+ forms carbonic acid which is excreted by the lungs
Na + HCO3- –> HCO3 + H+ –> H2CO3 –> H2O + CO2

Shifts K intracellularly

Question 17

Sodium bicarb: Indications

Answer 17

Severe metabolic acidosis (pH about 7.0)
Metabolic acidosis secondary to prolonged cardiac arrest. NOT given for resp acidosis

Drug overdose, severe diarrhea, lactic acidosis, renal disease, uncontrolled diabetes
Adjunct treatment for hyperkalemia with insulin
Sepsis guidelines use only if pH < 7.15

Question 18

Sodium bicarb: Dose and nursing considerations

Answer 18

Undiluted:
Preloaded syringe of 1amp of 8.4% (50mls) over 5 mins IV push

Diluted for continuous infusion:
3 amps in 850cc D5W, titrate to serum bicarb level. Usually 50mls/hr but may put pt in fluid overload.

DO NOT MIX WITH ANY OTHER DRUG will form precipitates.
Possible fluid overload, assess ABGs and Na