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Primacor Side Effects

Generic Name: milrinone

Note: This document contains side effect information about milrinone. Some of the dosage forms listed on this page may not apply to the brand name Primacor.

For the Consumer

Applies to milrinone: parenteral injection for iv infusion, parenteral injection for iv use

Side effects include:

Ventricular arrhythmias (e.g., ventricular ectopy, nonsustained ventricular tachycardia ), supraventricular arrhythmias, hypotension, headache.

For Healthcare Professionals

Applies to milrinone: intravenous solution


Cardiovascular side effects have included ventricular arrhythmias (12%), ventricular ectopic activity (8%), supraventricular arrhythmias (3.8%), sustained and nonsustained ventricular tachycardia (1% and 2.8%, respectively), ventricular fibrillation (0.2%), and atrial fibrillation. Hypotension (2.9%) and angina/chest pain (1.2%) have occurred. In addition, rare reports of torsades de pointes have been reported in postmarketing experience.[Ref]

Nervous system

Nervous system side effects have included headaches (2.9%) and tremor (0.4%). Dizziness is most often associated with hypotension.[Ref]


Hematologic side effects of reversible thrombocytopenia (0.4%), inhibition of platelet activity, and increased bleeding time have occurred. While these effects have been described in patients undergoing cardiac surgery who had received milrinone (the active ingredient contained in Primacor) for 12 to 24 hours, they have not been associated with acute administration of milrinone. The hematologic side effects of milrinone may be important in some patients who are awaiting cardiac catheterization, transplant, or other significant invasive procedures.[Ref]

Milrinone has been shown to inhibit human platelet thromboxane A2 synthesis and calcium uptake.[Ref]


General gastrointestinal complaints have been reported rarely.[Ref]


Hypersensitivity reactions including rare instances of bronchospasm and anaphylactic shock have been reported in postmarketing experience.[Ref]


Hepatic side effects including liver function test abnormalities have been reported in postmarketing experience.[Ref]


Other side effects including rash and skin reactions have been reported in postmarketing experience.[Ref]


Metabolic side effects have included rare reports of hypokalemia (0.6%).[Ref]


Respiratory side effects have been reported including isolated, spontaneous reports of bronchospasm.[Ref]


Dermatologic side effects including rash has been reported in postmarketing experience.


Local side effects including infusion site reaction has been reported in postmarketing experience.


1. Mehra MR, Ventura HO, Kapoor C, Stapleton DD, Zimmerman D, Smart FW "Safety and clinical utility of long-term intravenous Milrinone in advanced heart failure." Am J Cardiol 80 (1997): 61-4

2. "Product Information. Primacor (milrinone)." Sanofi Winthrop Pharmaceuticals, New York, NY.

3. Fleming GA, Murray KT, Yu C, et al. "Milrinone use is associated with postoperative atrial fibrillation after cardiac surgery." Circulation 118 (2008): 1619-25

4. MilfredLaforest SK, Shubert J, Mendoza B, Flores I, Eisen HJ, Pina IL "Tolerability of extended duration intravenous milrinone in patients hospitalized for advanced heart failure and the usefulness of uptitration of oral angiotensin-converting enzyme inhibitors." Am J Cardiol 84 (1999): 894-9

5. Packer M, Carver JR, Rodeheffer RJ, et al "Effect of oral milrinone of mortality in severe chronic heart failure." N Engl J Med 325 (1991): 1468-75

6. Jeremy JY, Gill J, Mikhailidis D "Effect of milrinone on thromboxane A2 synthesis, cAMP phosphodiesterase and 45Ca2+ uptake by human platelets." Eur J Pharmacol 245 (1993): 67-73

7. Kikura M, Lee MK, Safon RA, Bailey JM, Levy JH "The effects of milrinone on platelets in patients undergoing cardiac surgery." Anesth Analg 81 (1995): 44-8

8. Hasegawa R "Milrinone, a new agent for the treatment of congestive heart failure." Clin Pharm 5 (1986): 201-5

Some side effects of Primacor may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.