Corotrop (Milrinone)
Inotropic agent and vasodilator for severe heart failure
Quick facts about Corotrop (milrinone)
Key Takeaways About Corotrop
- Hospital-only medication: Corotrop is given exclusively as an intravenous infusion in hospital settings with continuous cardiac monitoring
- Short-term treatment: Intended only for short-term use in severe heart failure that has not responded to other medications; not for long-term therapy
- Dual mechanism: Milrinone both strengthens heart contractions (positive inotropic effect) and dilates blood vessels, reducing the workload on the heart
- Arrhythmia risk: Can promote cardiac arrhythmias, especially in patients with low potassium levels or high digoxin levels; continuous ECG monitoring is essential
- Pediatric use approved: Can be used in children for up to 35 hours for severe heart failure or post-cardiac surgery heart failure under close monitoring
What Is Corotrop and What Is It Used For?
Corotrop is a prescription intravenous medication containing milrinone, a phosphodiesterase-3 (PDE3) inhibitor that increases cardiac output and dilates blood vessels. It is used for the short-term treatment of severe heart failure in adults and children when conventional therapy has failed.
Corotrop belongs to a class of medications known as phosphodiesterase-3 (PDE3) inhibitors. The active ingredient, milrinone, works through a unique dual mechanism: it enhances the force of the heart's contractions (positive inotropic effect) while simultaneously relaxing blood vessel walls (vasodilation). This combination results in improved cardiac output — the amount of blood the heart pumps per minute — and reduced resistance in the blood vessels, making it easier for the heart to pump blood throughout the body.
Unlike some other inotropic agents such as dobutamine that work primarily through beta-adrenergic receptor stimulation, milrinone acts independently of these receptors. By inhibiting the PDE3 enzyme in cardiac and vascular smooth muscle cells, milrinone increases intracellular levels of cyclic adenosine monophosphate (cAMP). This leads to enhanced calcium availability in cardiac muscle cells and smooth muscle relaxation in blood vessels, producing both inotropic and vasodilatory effects.
Approved indications in adults
In adult patients, Corotrop is indicated for the short-term treatment of severe congestive heart failure (acute decompensated heart failure) that has not responded adequately to conventional maintenance therapy such as digoxin, diuretics, and vasodilators. It is most commonly used in intensive care units and cardiac care units for patients experiencing:
- Severe left ventricular failure: When the left ventricle of the heart cannot pump sufficient blood to meet the body's needs, despite optimal medical therapy
- Low cardiac output syndrome: Following cardiac surgery or during acute cardiac decompensation, where the heart's pumping function is critically reduced
- Acute exacerbation of chronic heart failure: When a patient with existing heart failure experiences a sudden and severe worsening of symptoms
Approved indications in children
In pediatric patients, Corotrop may be used for short-term treatment (up to 35 hours) in two specific clinical scenarios:
- Severe heart failure: When the child's heart cannot pump sufficient blood to meet the body's needs and other medications have not provided adequate improvement
- Acute heart failure following cardiac surgery: When the heart temporarily has difficulty pumping blood adequately after a surgical procedure on the heart
Corotrop requires continuous monitoring of cardiac function, blood pressure, and ECG throughout the duration of treatment. It should only be administered in facilities equipped for advanced hemodynamic monitoring by healthcare professionals experienced in the management of acute heart failure.
What Should You Know Before Taking Corotrop?
Corotrop must not be used in patients with allergy to milrinone or its excipients, or in patients with severe obstruction of the aortic or pulmonary valves. Special caution is required for patients with arrhythmias, kidney disease, low blood pressure, or reduced platelet counts.
Before initiating treatment with Corotrop, it is essential that your healthcare team is fully aware of your complete medical history, current medications, and any known allergies. Milrinone is a potent cardiovascular agent, and its use requires careful assessment of both the potential benefits and risks for each individual patient. The following sections detail the key contraindications, warnings, and precautions that must be considered before and during therapy.
Contraindications
Corotrop must not be used in the following situations:
- Hypersensitivity: If you are allergic to milrinone or any of the other ingredients in this medicine, including glucose, lactic acid, sodium hydroxide, and water for injections
- Severe valvular obstruction: If you have severe narrowing (stenosis) of the aortic or pulmonary heart valves (obstructive aortic or pulmonary valve disease). In these conditions, increasing the force of cardiac contraction could be harmful, as the obstruction prevents the increased cardiac output from being effectively ejected
Warnings and Precautions
Speak with your doctor or pharmacist before receiving Corotrop if any of the following conditions apply to you:
Cardiac arrhythmias: If you have or are expected to be diagnosed with certain types of heart rhythm disturbances — such as atrial flutter, atrial fibrillation, or ventricular arrhythmias — Corotrop may promote these arrhythmias. The risk of arrhythmias is further increased when blood potassium levels are low (hypokalemia) and/or when levels of the cardiac medication digitalis (digoxin) are elevated. Your doctor will determine whether additional treatment, dose adjustment, or continuous ECG monitoring is necessary.
Low cardiac filling pressure: If your heart is suspected to have low filling pressure (preload), for example due to previous treatment with diuretics (water pills), your doctor will assess and correct your filling pressure before starting milrinone therapy. Administering milrinone to patients with inadequate preload could lead to a dangerous drop in blood pressure.
Kidney disease: If you have impaired kidney function, your doctor will perform appropriate tests before and during treatment. Milrinone is primarily cleared from the body by the kidneys, so dose adjustments may be necessary in patients with renal impairment to prevent drug accumulation and toxicity.
Low blood pressure (hypotension): If you already have low blood pressure, careful monitoring is essential because milrinone's vasodilatory effects can further reduce blood pressure. Your doctor will take this into account when determining the appropriate dose and monitoring frequency.
Blood count abnormalities: If you have a reduced number of platelets (thrombocytopenia), red blood cells, or low hemoglobin levels, Corotrop may only be used under careful monitoring of your blood counts, as treatment can cause further decreases in these values.
Throughout the duration of Corotrop treatment, continuous monitoring of heart rate, blood pressure, ECG, fluid balance, and electrolyte levels (especially potassium) is mandatory. Any signs of arrhythmia, significant hypotension, or other adverse cardiovascular effects require immediate medical intervention.
Special considerations for children
In addition to the warnings listed above for adults, the following considerations apply specifically to pediatric patients:
- Before starting the injection, the doctor will verify that the child's heart rhythm and blood pressure are stable, and will order blood tests
- The injection will not be started if the child's heart rhythm or blood pressure is unstable
- Special caution is required in premature infants or infants with low birth weight
- Children with patent ductus arteriosus (a connection between two large blood vessels that should have closed after birth) require careful assessment, as milrinone may worsen this condition. Patent ductus arteriosus can cause excess fluid in the lungs, bleeding, intestinal damage, and can be life-threatening
Pregnancy and Breastfeeding
There are no clinical data on the use of milrinone in pregnant women. Animal studies have not shown direct or indirect harmful effects on pregnancy, prenatal development, delivery, or postnatal development. However, the absence of human data means that Corotrop should be used during pregnancy only when the potential benefit clearly outweighs the potential risk to the fetus.
It is unknown whether milrinone is excreted in human breast milk. As a precautionary measure, breastfeeding must be discontinued if treatment with Corotrop is required. If you are pregnant, breastfeeding, suspect you may be pregnant, or are planning to have a baby, discuss this with your doctor before receiving this medication.
Elderly patients
There are no specific dosage recommendations for elderly patients. Controlled pharmacokinetic studies have not shown any age-related effects on the distribution or elimination of milrinone. However, as older patients are more likely to have impaired kidney function and other comorbidities, careful monitoring and dose adjustment based on clinical response remain important.
Corotrop contains less than 1 mmol (23 mg) of sodium per ml, meaning it is essentially sodium-free. This is relevant for patients on a sodium-restricted diet.
How Does Corotrop Interact with Other Drugs?
Milrinone can have additive inotropic effects with other heart-strengthening drugs such as dobutamine. The risk of arrhythmias increases when combined with digoxin (especially at high levels) or when potassium-lowering medications cause hypokalemia. Always inform your doctor about all medications you are taking.
Drug interactions are an important consideration when using Corotrop, particularly because patients receiving this medication for severe heart failure are typically on multiple other cardiovascular drugs. Milrinone's mechanism of action — inhibition of phosphodiesterase-3 — is distinct from that of beta-adrenergic agonists and cardiac glycosides, which means it can produce additive effects when combined with these agents. Your healthcare team will carefully assess all your current medications to optimize therapy and minimize risks.
Major interactions
The following drug interactions are clinically significant and require careful monitoring or dose adjustment:
| Drug / Drug Class | Interaction | Clinical Significance | Management |
|---|---|---|---|
| Dobutamine | Additive positive inotropic effects; enhanced cardiac contractility | Can be therapeutically beneficial but increases risk of tachyarrhythmias | Close hemodynamic monitoring; titrate doses carefully |
| Digoxin | Combined inotropic effects; elevated digoxin levels increase arrhythmia risk with milrinone | High digoxin levels combined with milrinone significantly increase ventricular arrhythmia risk | Monitor digoxin levels; continuous ECG monitoring; correct hypokalemia |
| Loop diuretics (furosemide) | Diuretic-induced hypokalemia increases risk of arrhythmias with milrinone | Low potassium levels potentiate milrinone-associated arrhythmias | Monitor and correct potassium levels before and during milrinone therapy |
| Other vasodilators | Additive vasodilatory effects leading to excessive blood pressure reduction | Severe hypotension may occur | Monitor blood pressure closely; adjust doses accordingly |
Minor interactions and considerations
When Corotrop is given concurrently with other cardiac inotropic agents (medications that increase the force of the heart's contractions, such as dobutamine), milrinone can enhance the positive inotropic effect of these medications, and vice versa. This additive effect can be used therapeutically under careful monitoring, but it also means that the combined effect on heart rate and rhythm must be closely watched.
Although formal interaction studies with milrinone are limited, clinicians should be aware that any medication that lowers blood potassium levels (including corticosteroids, certain antibiotics like amphotericin B, and insulin) can increase the arrhythmogenic potential of milrinone. Similarly, medications that lower blood pressure should be used cautiously in combination with milrinone due to its inherent vasodilatory properties.
Always inform your doctor or pharmacist about all medications you are currently taking, have recently taken, or plan to take, including over-the-counter medications, herbal supplements, and vitamins. This is essential for safe and effective use of Corotrop.
What Is the Correct Dosage of Corotrop?
Corotrop is administered intravenously in hospital. The typical adult regimen involves a loading dose of 50 mcg/kg over 10 minutes, followed by a continuous infusion of 0.375–0.75 mcg/kg/min. Dosage is individually adjusted by the physician based on hemodynamic response and kidney function.
Corotrop is a hospital-only medication that is administered as an intravenous injection or infusion. The dosage is always determined and adjusted individually by the treating physician based on the patient's clinical condition, hemodynamic response, and renal function. Patients receiving Corotrop must have continuous monitoring of cardiac function, blood pressure, ECG, fluid balance, and electrolyte levels throughout the duration of treatment.
Adults
Standard dosing regimen for adults
Loading dose: 50 micrograms per kilogram of body weight (50 mcg/kg), administered intravenously over approximately 10 minutes.
Maintenance infusion: 0.375 to 0.75 micrograms per kilogram per minute (0.375–0.75 mcg/kg/min), administered as a continuous intravenous infusion.
Dose titration: The infusion rate is adjusted within the above range based on the patient's hemodynamic and clinical response. Total daily dose should not exceed 1.13 mg/kg.
The loading dose is designed to rapidly achieve therapeutic blood levels of milrinone, while the maintenance infusion sustains these levels for the duration of treatment. Your physician will closely monitor your hemodynamic parameters — including cardiac output, pulmonary capillary wedge pressure, and systemic vascular resistance — to optimize the infusion rate.
Children
Pediatric dosing considerations
Dosing in children is weight-based and individually determined by the treating physician. Treatment duration is limited to a maximum of 35 hours. The physician will monitor cardiac rhythm, blood pressure, and blood parameters closely throughout treatment.
Platelet counts should be monitored regularly in pediatric patients, as thrombocytopenia occurs more frequently in children than in adults, with risk increasing with infusion duration.
Elderly
There are no specific dosage adjustments required solely on the basis of age. However, since many elderly patients have some degree of renal impairment, kidney function should be assessed before and during treatment, and the dose should be adjusted accordingly. Elderly patients may also be more susceptible to the hypotensive effects of milrinone and should be monitored closely.
Patients with kidney impairment
Because milrinone is primarily eliminated by the kidneys, patients with impaired renal function may require reduced infusion rates. Your doctor will use your kidney function tests (such as creatinine clearance) to determine the appropriate maintenance infusion rate. This is critical to prevent drug accumulation and associated adverse effects.
Missed Dose
Since Corotrop is administered as a continuous infusion by healthcare professionals in a hospital setting, it is very unlikely that a dose would be missed. However, if you believe there has been any interruption in your infusion, inform your nurse or doctor immediately so they can resume the appropriate dosing.
Overdose
In the event of an overdose, the following effects may occur:
- Hypotension (dangerously low blood pressure): Due to the potent vasodilatory effects of milrinone
- Cardiac arrhythmias: Including potentially life-threatening ventricular arrhythmias
In the case of overdose, your doctor will immediately discontinue the infusion or reduce the infusion rate and initiate appropriate supportive treatment. There is no specific antidote for milrinone. Treatment is supportive and directed at managing the symptoms, including intravenous fluids for hypotension and antiarrhythmic medications if needed.
There is no known specific antidote for milrinone. Because of its relatively short half-life (approximately 2.3 hours in patients with normal kidney function), the effects of the drug will generally diminish after the infusion is stopped, but longer elimination times may be expected in patients with impaired renal function.
What Are the Side Effects of Corotrop?
Common side effects of Corotrop include headache, fainting, palpitations, cardiac arrhythmias, low blood pressure, and worsening heart failure. Less common effects include low platelet count, low potassium, tremor, atrial fibrillation, and chest pain. Rare but serious effects include anaphylactic shock and torsade de pointes.
Like all medicines, Corotrop can cause side effects, although not everyone will experience them. The side effects are categorized below by their frequency of occurrence. Because Corotrop is used in critically ill patients with severe cardiac conditions, it can sometimes be difficult to distinguish drug-related side effects from symptoms of the underlying disease. Your healthcare team will continuously monitor for adverse effects throughout treatment and adjust therapy as needed.
Common
- Headache
- Syncope (fainting)
- Palpitations (awareness of heartbeat)
- Cardiac arrhythmias (abnormal heart rhythms)
- Hypotension (low blood pressure)
- Worsening of heart failure
Uncommon
- Thrombocytopenia (decreased platelet count)
- Hypokalemia (low potassium levels)
- Tremor
- Atrial fibrillation
- Angina pectoris (severe chest pain with tightness and shortness of breath)
- Nausea and vomiting
- Abnormal liver function tests
Very Rare
- Anaphylactic shock (severe allergic reaction)
- Torsade de pointes (a particularly dangerous type of ventricular arrhythmia)
- Bronchospasm (spastic contraction of the airways)
- Skin rash
Not Known
- Decrease in red blood cells and/or hemoglobin concentration
- Intraventricular hemorrhage (bleeding in fluid-filled areas surrounding the brain)
- Renal failure (particularly in association with hypotension)
- Infusion site reactions
Life-threatening cardiac arrhythmias have occurred in patients with pre-existing irregular heart rhythms, electrolyte disturbances (particularly low potassium levels), and/or elevated digoxin levels. Continuous ECG monitoring and regular electrolyte checks are mandatory during milrinone therapy.
Additional side effects in children
In addition to the side effects reported in adults, the following have been observed in pediatric patients:
- Patent ductus arteriosus: A connection between two major blood vessels (the aorta and the pulmonary artery) that persists when it should have closed. This can cause excess fluid in the lungs, bleeding, bowel damage (necrotizing enterocolitis), and can be life-threatening
- Thrombocytopenia: Decreased platelet count appears to occur more frequently in children than in adults, and the risk increases with longer infusion duration
- Cardiac arrhythmias: Appear to occur less frequently in children than in adults
Reporting side effects
If you experience any side effects during or after treatment with Corotrop, it is important to report them to your healthcare provider. Reporting suspected adverse reactions helps authorities continuously monitor the benefit-risk balance of the medication. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national pharmacovigilance authority.
How Should You Store Corotrop?
Store Corotrop below 30°C, protected from freezing. Keep out of sight and reach of children. Do not use after the expiration date on the packaging. After dilution, the solution should be used within 12 hours.
Proper storage of Corotrop is essential to maintain its efficacy and safety. While storage is typically handled by hospital pharmacy staff, the following guidelines apply:
- Temperature: Store at or below 30°C (86°F). Do not refrigerate or freeze — protect from cold
- Shelf life: Do not use after the expiration date printed on the carton and ampoule (EXP). The expiration date refers to the last day of the stated month
- After dilution: Once diluted, the solution should be used within 12 hours. Any unused solution should be discarded
- Appearance: The solution is a clear, slightly yellow liquid. Do not use if the solution is discolored, cloudy, or contains particulate matter
- Keep out of reach: Keep this medication out of the sight and reach of children
- Disposal: Do not dispose of medication via wastewater or household waste. Ask your pharmacist about proper disposal of unused medicines to help protect the environment
Corotrop is supplied as a clear, slightly yellow solution in glass ampoules. Each ampoule contains 10 ml of solution (10 mg milrinone per ampoule). The product is available in packages of 10 ampoules (10 × 10 ml).
What Does Corotrop Contain?
Each ml of Corotrop solution contains 1 mg milrinone as the active ingredient. Inactive ingredients include glucose, lactic acid, sodium hydroxide, and water for injections. Each 10 ml ampoule contains a total of 10 mg milrinone.
Understanding the full composition of any medication is important for identifying potential allergens and ensuring compatibility with other treatments. The complete formulation of Corotrop is as follows:
Active ingredient
Each ml of Corotrop solution for injection contains 1 mg milrinone (equivalent to milrinone lactate). Each 10 ml ampoule therefore contains 10 mg milrinone.
Inactive ingredients (excipients)
- Glucose (dextrose): Used as a solubilizing agent and to maintain isotonicity
- Lactic acid: Used as a pH-adjusting agent
- Sodium hydroxide: Used for pH adjustment
- Water for injections: Serves as the solvent for the solution
The solution is essentially sodium-free, containing less than 1 mmol (23 mg) of sodium per ml. This is relevant for patients on sodium-restricted diets or those with conditions that require careful sodium management.
Frequently Asked Questions About Corotrop
Medical References and Sources
This article is based on the approved product information and current international medical guidelines. All claims are supported by scientific evidence from peer-reviewed sources.
- European Medicines Agency (EMA). Corotrop — Summary of Product Characteristics (SmPC). Regulatory-approved prescribing information for milrinone (Corotrop).
- McDonagh TA, Metra M, Adamo M, et al. (2023). "2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC)." European Heart Journal. 42(36):3599–3726. Updated 2023. European guidelines for heart failure management including inotropic therapy recommendations.
- Heidenreich PA, Bozkurt B, Aguilar D, et al. (2022). "2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure." Journal of the American College of Cardiology. 79(17):e263–e421. American guidelines for heart failure management, including acute decompensated heart failure.
- World Health Organization (WHO). "WHO Model List of Essential Medicines — 23rd List (2023)." WHO Essential Medicines WHO's comprehensive list of essential medicines for global health systems.
- British National Formulary (BNF). "Milrinone — Drug Information." National Institute for Health and Care Excellence (NICE). Comprehensive drug monograph for milrinone including dosing, interactions, and adverse effects.
- Packer M, Carver JR, Rodeheffer RJ, et al. (1991). "Effect of oral milrinone on mortality in severe chronic heart failure." New England Journal of Medicine. 325(21):1468–1475. Landmark PROMISE trial demonstrating risks of long-term milrinone use in heart failure.
- Cuffe MS, Califf RM, Adams KF Jr, et al. (2002). "Short-term intravenous milrinone for acute exacerbation of chronic heart failure: a randomized controlled trial (OPTIME-CHF)." JAMA. 287(12):1541–1547. Randomized trial evaluating short-term IV milrinone in acute heart failure exacerbation.
- Hoffman TM, Wernovsky G, Atz AM, et al. (2003). "Efficacy and safety of milrinone in preventing low cardiac output syndrome in infants and children after corrective surgery for congenital heart disease." Circulation. 107(7):996–1002. PRIMACORP trial evaluating milrinone in pediatric cardiac surgery patients.
Evidence grading: This article uses the GRADE framework (Grading of Recommendations Assessment, Development and Evaluation) for evidence-based medicine. Recommendations from ESC and AHA/ACC guidelines are classified using their respective evidence grading systems, with Level 1A representing the highest quality of evidence.
iMedic Medical Editorial Team
Specialists in cardiology, clinical pharmacology, and intensive care
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iMedic's medical content is produced by a team of licensed specialist physicians and medical experts with solid academic background and clinical experience. Our editorial team includes:
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Licensed physicians specializing in cardiology and heart failure management, with documented experience in acute cardiac care and inotropic therapy.
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Experts in drug pharmacology, pharmacokinetics, drug interactions, and evidence-based prescribing in critical care settings.
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Practicing physicians with extensive experience in managing critically ill patients with acute heart failure in intensive care units.
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