General

High Alert Medication: This medication bears a heightened risk of causing significant patient harm when it is used in error.

Pronunciation:
mill-ri-none

Trade Name(s)

• Primacor

Ther. Class.

inotropics

Indications

Short-term treatment of HF unresponsive to conventional therapy with digoxin, diuretics, and vasodilators.

Action

• Increases myocardial contractility.
• Decreases preload and afterload by a direct dilating effect on vascular smooth muscle.

Therapeutic Effect(s):

Increased cardiac output (inotropic effect).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Moderately distributed to tissues.

Metabolism and Excretion: 80–90% excreted unchanged by the kidneys.

Half-life: 2.3 hr (↑ in renal impairment).

TIME/ACTION PROFILE (hemodynamic effects)

Contraindication/Precautions

Contraindicated in:

• Hypersensitivity;
• Severe aortic or pulmonic valvular heart disease;
• Hypertrophic subaortic stenosis (may ↑ outflow tract obstruction).

Use Cautiously in:

• History of arrhythmias, electrolyte abnormalities, abnormal digoxin levels, or insertion of vascular catheters (↑ risk of ventricular arrhythmias);
• Renal impairment (↓ infusion rate if CCr is <50 mL/min);
• OB:  Safety not established in pregnancy;
• Lactation:  Safety not established in breastfeeding.

Adverse Reactions/Side Effects

CV: angina pectoris, chest pain, hypotension, supraventricular arrhythmias, VENTRICULAR ARRHYTHMIAS

Derm: rash

GI: ↑ liver enzymes

Hemat: thrombocytopenia

Neuro: headache, tremor

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

None reported.

Route/Dosage

IV (Adults): Loading dose:  50 mcg/kg followed by  Continuous infusion  at 0.5 mcg/kg/min (range 0.375–0.75 mcg/kg/min).

IV (Infants and Children): Loading dose:  50 mcg/kg over 10 min followed by  Continuous infusion  at 0.5 mcg/kg/min (range 0.25–0.75 mcg/kg/min).

Availability (generic available)

Solution for injection: 1 mg/mL

Premixed infusion: 20 mg/100 mL, 40 mg/200 mL

Assessment

• Monitor intake, output, and daily weight. Assess patient for resolution of signs and symptoms of HF (peripheral edema, dyspnea, rales/crackles, weight gain) and improvement in hemodynamic parameters (↑ cardiac output and cardiac index, ↓ pulmonary capillary wedge pressure). Correct effects of previous aggressive diuretic therapy to allow for optimal filling pressure.
• Monitor BP and ECG continuously during infusion. Arrhythmias are common and may be life-threatening. The risk of ventricular arrhythmias is ↑ in patients with history of arrhythmias, electrolyte abnormalities, abnormal digoxin levels, or insertion of vascular catheters.  If hypotension or arrhythmias occurs,  slow or discontinue therapy depending on severity.

Lab Test Considerations:

Monitor electrolytes and renal function frequently during therapy. Correct hypokalemia prior to administration to ↓ risk of arrhythmias.

• Monitor platelet count during therapy.

High Alert: Overdose manifests as hypotension. Dose should be ↓ or discontinued until patient is stabilized. Provide circulatory support as indicated.

Implementation

• High Alert: Accidental overdose of milrinone can cause patient harm or death. Have 2nd practitioner independently check original order, dose calculations, and infusion pump settings.

Patient/Family Teaching

• Explain purpose and side effects of medication. Advise patient to read  Patient Information  before starting therapy.
• Advise patient to notify health care provider immediately if bronchospasm or other signs of anaphylaxis occur.
• Rep:  Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding.

Evaluation/Desired Outcomes

Decrease in the signs and symptoms of HF.

• Improvement in hemodynamic parameters.