Primacor

milrinone

(mill-ri-none) milrinone,

Primacor

(trade name)

Classification

Therapeutic: inotropics
Pregnancy Category: C

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 effects

Increased cardiac output (inotropic effect).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.Distribution: Unknown.Metabolism and Excretion: 80–90% excreted unchanged by the kidneys.Half-life: 2.3 hr (↑ in renal impairment).

Time/action profile (hemodynamic effects)

ROUTEONSETPEAKDURATION
IV5–15 minunknown3–6 hr

Contraindications/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); Obstetric / Lactation: Pregnancy or lactation.

Adverse Reactions/Side Effects

Central nervous system

  • headache
  • tremor

Cardiovascular

  • ventricular arrhythmias (life-threatening)
  • angina pectoris
  • chest pain
  • hypotension
  • supraventricular arrhythmias

Cardiovascular

  • skin rash

Gastrointestinal

  • ↑ liver enzymes

Fluid and Electrolyte

  • hypokalemia

Hematologic

  • thrombocytopenia

Interactions

Drug-Drug interaction

None significant.

Route/Dosage

Intravenous (Adults) Loading dose—50 mcg/kg followed by continuous infusion at 0.5 mcg/kg/min (range 0.375–0.75 mcg/kg/min).Intravenous (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)

Injection: 1 mg/mL Premixed infusion: 20 mg/100 mL, 40 mg/200 mL

Nursing implications

Nursing assessment

  • Monitor heart rate and BP continuously during administration. Slow or discontinue if BP drops excessively.
  • Monitor intake and 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 (increase in cardiac output and cardiac index, decrease in pulmonary capillary wedge pressure). Correct effects of previous aggressive diuretic therapy to allow for optimal filling pressure.
  • Monitor ECG continuously during infusion. Arrhythmias are common and may be life threatening. The risk of ventricular arrhythmias is increased in patients with a history of arrhythmias, electrolyte abnormalities, abnormal digoxin levels, or insertion of vascular catheters.
  • Lab Test Considerations: Monitor electrolytes and renal function frequently during administration. Correct hypokalemia prior to administration to decrease the risk of arrhythmias.
    • Monitor platelet count during therapy.
  • high alert: Overdose manifests as hypotension. Dose should be decreased or discontinued. Supportive measures may be necessary.

Potential Nursing Diagnoses

Decreased cardiac output (Indications)

Implementation

  • high alert: Accidental overdose of milrinone can cause patient harm or death. Have second practitioner independently check original order, dose calculations, and infusion pump settings.
  • Intravenous Administration
  • pH: 3.2–4.0.
  • Diluent: Loading dose may be administered undiluted. May also be diluted in 0.9% NaCl, 0.45% NaCl, or D5W for ease of administration.Concentration: 1 mg/mL.
  • Rate: Administer the loading dose over 10 min.
  • Continuous Infusion: Diluent: Milrinone drawn from vials must be diluted. Dilute 10 mg (10 mL) of milrinone in 40 mL of diluent or 20 mg (20 mL) of milrinone in 80 mL of diluent. Compatible diluents include 0.45% NaCl, 0.9% NaCl, and D5W. Premixed infusions are already diluted and ready to use. Admixed solutions are stable for 72 hr at room temperature. Stability of premixed infusions based on manufacturer's expiration date. Do not use solutions that are discolored or contain particulate matter.Concentration: 200 mcg/mL.
  • Rate: Based on patient's weight (see Route/Dosage section). Titrate according to hemodynamic and clinical response.
  • Y-Site Compatibility: acyclovir, alfentanil, allopurinol, amifostine, amikacin, aminophylline, amiodarone, amphotericin B liposome, ampicillin, anidulafungin, argatroban, atracurium, aztreonam, bivalirudin, bleomycin, bumetanide, buprenorphine, busulfan, butorphanol, calcium chloride, calcium gluconate, carboplatin, carmustine, caspofungin, cefazolin, cefepime, cefotaxime, cefotetan, cefoxitin, ceftaroline, ceftazidime, ceftriaxone, cefuroxime, chloramphenicol, chlorpromazine, ciprofloxacin, cisatracurium, cisplatin, clindamycin, cyclophosphamide, cyclosporine, cytarabine, dactinomycin, daptomycin, dexamethasone sodium phosphate, dexmeditomidine, digoxin, diltiazem, dobutamine, docetaxel, dopamine, doripenem, doxacurium, doxorubicin, doxycycline, droperidol, enalaprilat, ephedrine, epinephrine, epirubicin, eptifibatide, ertapenem, erythromycin, etoposide, etoposide phosphate, fenoldopam, fentanyl, fluconazole, fludarabine, fluorouracil, ganciclovir, gemcitabine, gentamicin, glycopyrrolate, granisetron, haloperidol, heparin, hetastarch, hydralazine, hydrocortisone, hydromorphone, idarubicin, ifosfamide, insulin, irinotecan, isoproterenol, ketamine, ketorolac, labetalol, levofloxacin, linezolid, lorazepam, magnesium sulfate, mannitol, mechlorethamine, melphalan, meperidine, meropenem, methohexital, methotrexate, methyldopate, methylprednisolone sodium succinate, metoclopramide, metoprolol, metronidazole, micafungin, midazolam, mitoxandrone, morphine, mycophenolate, nafcillin, nalbuphine, naloxone, nesiritide, nicardipine, nitroglycerin, nitroprusside, norepinephrine, octreotide, oxacillin, oxaliplatin, oxytocin, paclitaxel, palonosetron, pamidronate, pancuronium, pemetrexed, pentobarbital, phenobarbital, phenylephrine, piperacillin/tazobactam, potassium acetate, potassium chloride, potassium phosphates, prochlorperazine, promethazine, propofol, propranolol, quinupristin/dalfopristin, ranitidine, remifentanil, rocuronium, sodium acetate, sodium bicarbonate, sodium phosphates, streptozocin, succinylcholine, sufentanil, tacrolimus, telavancin, teniposide, theophylline, thiopental, thiotepa, ticarcillin/clavulanate, tigecycline, tirofiban, tobramycin, torsemide, vancomycin, vasopressin, vecuronium, verapamil, vincristine, vinorelbine, voriconazole, zidovudine, zoledronic acid
  • Y-Site Incompatibility: amphotericin B colloidal, amphotericin B lipid complex, dantrolene, diazepam, diphenhydramine, esmolol, furosemide, hydroxyzine, imipenem/cilastatin, lidocaine, ondansetron, pantoprazole, phenytoin, procainamide

Patient/Family Teaching

  • Inform patient and family of reasons for administration. Milrinone is not a cure but is a temporary measure to control the symptoms of HF.

Evaluation/Desired Outcomes

  • Decrease in the signs and symptoms of HF.
    • Improvement in hemodynamic parameters.

Primacor

A brand name for the PHOSPHODIESTERASE INHIBITOR drug MILRINONE.