Milrinone Lactate

INDICATIONS AND USAGE Milrinone lactate injection is indicated for the short-term intravenous treatment of patients with acute decompensated heart failure. Patients receiving milrinone should be observed closely with appropriate electrocardiographic equipment. The facility for immediate treatment of potential cardiac events, which may include life threatening ventricular arrhythmias, must be available. The majority of experience with intravenous milrinone has been in patients receiving digoxin and diuretics. There is no experience in controlled trials with infusions of milrinone for periods exceeding 48 hours.

DOSAGE AND ADMINISTRATION Milrinone Lactate in 5% Dextrose Injection should not be used for administering a loading dose. The information regarding loading doses for milrinone is for 1 mg/mL vial only. A loading dose of milrinone lactate injection (1 mg [base]/mL) should be administered followed by a continuous infusion (maintenance dose) according to the following guidelines: Loading Dose 50 mcg/kg: Administer slowly over 10 minutes. The table below shows the loading dose in milliliters (mL) of milrinone (1 mg/mL) by patient body weight (kg). Loading Dose (mL) Using 1 mg/mL Concentration Patient Body Weight (kg) kg 30 40 50 60 70 80 90 100 110 120 mL 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 The loading dose may be given undiluted, but diluting to a rounded total volume of 10 or 20 mL (see Maintenance Dose for diluents) may simplify the visualization of the injection rate. Maintenance Dose Infusion Rate Total Daily Dose (24 hours) Minimum 0.375 mcg/kg/min 0.59 mg/kg Administer as a continuous intravenous infusion Standard 0.50 mcg/kg/min 0.77 mg/kg Maximum 0.75 mcg/kg/min 1.13 mg/kg Milrinone drawn from vials should be diluted prior to maintenance dose administration. The diluents that may be used are 0.45% Sodium Chloride Injection, USP, 0.9% Sodium Chloride Injection, USP, or 5% Dextrose Injection, USP. The table below shows the volume of diluent in milliliters (mL) that must be used to achieve 200 mcg/mL concentration for infusion, and the resultant total volumes. Desired Infusion Concentration mcg/mL Milrinone 1 mg/mL (mL) Diluent (mL) Total Volume (mL) 200 10 40 50 200 20 80 100 The infusion rate should be adjusted according to hemodynamic and clinical response. Patients should be closely monitored. In controlled clinical studies, most patients showed an improvement in hemodynamic status as evidenced by increases in cardiac output and reductions in pulmonary capillary wedge pressure. Note : See " Dosage Adjustment in Renally Impaired Patients ." Dosage may be titrated to the maximum hemodynamic effect and should not exceed 1.13 mg/kg/day. Duration of therapy should depend upon patient responsiveness. The maintenance dose in mL/hr by patient body weight (kg) may be determined by reference to the following table. Note : Milrinone Lactate in 5% Dextrose Injection supplied in 100 mL and 200 mL Flexible Containers (200 mcg/mL in 5% Dextrose Injection) need not be diluted prior to use. Milrinone Infusion Rate(mL/hr) Using 200 mcg/mL Concentration Maintenance Dose (mcg/kg/min) Patient Body Weight (kg) 30 40 50 60 70 80 90 100 110 120 0.375 3.4 4.5 5.6 6.8 7.9 9 10.1 11.3 12.4 13.5 0.4 3.6 4.8 6 7.2 8.4 9.6 10.8 12 13.2 14.4 0.5 4.5 6 7.5 9 10.5 12 13.5 15 16.5 18 0.6 5.4 7.2 9 10.8 12.6 14.4 16.2 18 19.8 21.6 0.7 6.3 8.4 10.5 12.6 14.7 16.8 18.9 21 23.1 25.2 0.75 6.8 9 11.3 13.5 15.8 18 20.3 22.5 24.8 27 When administering milrinone lactate by continuous infusion, it is advisable to use a calibrated electronic infusion device. The Flexible Container has a concentration of milrinone equivalent to 200 mcg/mL in 5% Dextrose Injection and is more convenient to use than dilutions prepared from the vials. To use the Flexible Container, tear the overwrap at the notch and remove the Pre-Mix solution container. Squeeze the container firmly to check for leaks. Discard the container if leaks are found since the sterility of the product could be affected. Do not add supplementary medication. To prepare the container for administration of milrinone intravenously, use aseptic techniques. 1. The flow control clamp of the administration set is closed. 2. The cover of the outlet port at the bottom of the container is removed. 3. Noting the full directions on the administration set carton, the piercing pin of the set is inserted into the port with a twisting motion until it is firmly seated. 4. The container is suspended on the hanger. 5. The drip chamber is squeezed and released to establish the fill level. 6. The flow control clamp is opened to …

WARNINGS Whether given orally or by continuous or intermittent intravenous infusion, milrinone has not been shown to be safe or effective in the longer (greater than 48 hours) treatment of patients with heart failure. In a multicenter trial of 1088 patients with Class III and IV heart failure, long-term oral treatment with milrinone was associated with no improvement in symptoms and an increased risk of hospitalization and death. In this study, patients with Class IV symptoms appeared to be at particular risk of life-threatening cardiovascular reactions. There is no evidence that milrinone given by long-term continuous or intermittent infusion does not carry a similar risk. The use of milrinone both intravenously and orally has been associated with increased frequency of ventricular arrhythmias, including nonsustained ventricular tachycardia. Long-term oral use has been associated with an increased risk of sudden death. Hence, patients receiving milrinone should be observed closely with the use of continuous electrocardiographic monitoring to allow the prompt detection and management of ventricular arrhythmias.

CONTRAINDICATIONS Milrinone lactate injection is contraindicated in patients who are hypersensitive to it.

Drug Interactions No untoward clinical manifestations have been observed in limited experience with patients in whom milrinone was used concurrently with the following drugs: digitalis glycosides; lidocaine, quinidine; hydralazine, prazosin; isosorbide dinitrate, nitroglycerin; chlorthalidone, furosemide, hydrochlorothiazide, spironolactone; captopril; heparin, warfarin, diazepam, insulin; and potassium supplements.

Pregnancy Category C Oral administration of milrinone to pregnant rats and rabbits during organogenesis produced no evidence of teratogenicity at dose levels up to 40 mg/kg/day and 12 mg/kg/day, respectively. Milrinone did not appear to be teratogenic when administered intravenously to pregnant rats at doses up to 3 mg/kg/day (about 2.5 times the maximum recommended clinical intravenous dose) or pregnant rabbits at doses up to 12 mg/kg/day, although an increased resorption rate was apparent at both 8 mg/kg/day and 12 mg/kg/day (intravenous) in the latter species. There are no adequate and well-controlled studies in pregnant women. Milrinone should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers Caution should be exercised when milrinone lactate is administered to nursing women, since it is not known whether it is excreted in human milk.

ADVERSE REACTIONS Cardiovascular Effects In patients receiving milrinone in Phase II and III clinical trials, ventricular arrhythmias were reported in 12.1%: Ventricular ectopic activity, 8.5%; nonsustained ventricular tachycardia, 2.8%; sustained ventricular tachycardia, 1% and ventricular fibrillation, 0.2% (2 patients experienced more than one type of arrhythmia). Holter recordings demonstrated that in some patients injection of milrinone increased ventricular ectopy, including nonsustained ventricular tachycardia. Life-threatening arrhythmias were infrequent and when present have been associated with certain underlying factors such as preexisting arrhythmias, metabolic abnormalities (e.g., hypokalemia), abnormal digoxin levels and catheter insertion. Milrinone was not shown to be arrhythmogenic in an electrophysiology study. Supraventricular arrhythmias were reported in 3.8% of the patients receiving milrinone. The incidence of both supraventricular and ventricular arrhythmias has not been related to the dose or plasma milrinone concentration. Other cardiovascular adverse reactions include hypotension, 2.9% and angina/chest pain, 1.2%. In the post-marketing experience, there have been rare cases of “torsades de pointes” reported. CNS Effects Headaches, usually mild to moderate in severity, have been reported in 2.9% of patients receiving milrinone. Other Effects Other adverse reactions reported, but not definitely related to the administration of milrinone include hypokalemia, 0.6%; tremor, 0.4%; and thrombocytopenia, 0.4%. Isolated spontaneous reports of bronchospasm and anaphylactic shock have been received; and in the post-marketing experience, liver function test abnormalities and skin reactions such as rash have been reported. Post-Marketing Adverse Event Reports In addition to adverse events reported from clinical trials, the following events have been reported from worldwide post-marketing experience with milrinone: Isolated spontaneous reports of bronchospasm and anaphylactic shock. Liver function test abnormalities and skin reactions such as rash. Administration site conditions: Infusion site reaction. To report SUSPECTED ADVERSE REACTIONS, contact West-Ward Pharmaceutical Corp. at 1-877-233-2001 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .