MILRINONE LACTATE IN PLASTIC CONTAINER
Clinical safety rating: safe
No significant drug interactions Can cause ventricular arrhythmias and hypotension.
Selective phosphodiesterase III (PDE3) inhibitor with inotropic and vasodilator effects; inhibits cAMP degradation in cardiac and vascular smooth muscle, increasing intracellular cAMP and calcium influx, leading to positive inotropy and systemic/pulmonary vasodilation.
| Metabolism | Primarily hepatic metabolism (about 12% via glucuronidation); minimal renal metabolism (about 85% excreted unchanged in urine). |
| Excretion | Primarily renal (85%) as unchanged drug within 24 hours; minor biliary (approximately 15%) with enterohepatic recirculation. |
| Half-life | Terminal half-life approximately 2.4 hours (range 2–3 hours) in patients with normal renal function; may be prolonged to 3–4 hours in congestive heart failure; significantly extended (up to 8–10 hours) in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | Approximately 70% bound to plasma proteins (primarily albumin). |
| Volume of Distribution | 0.3–0.4 L/kg; indicates distribution primarily into extracellular fluid and limited tissue penetration. |
| Bioavailability | Intravenous: 100% (only route available; oral bioavailability is not clinically relevant due to extensive first-pass metabolism). |
| Onset of Action | Intravenous: 5–15 minutes for hemodynamic effects (increase in cardiac output, reduction in pulmonary capillary wedge pressure). |
| Duration of Action | Hemodynamic effects persist for 1–2 hours after discontinuation of a short-term infusion; prolonged effects may be seen with extended infusion due to accumulation. |
Intravenous: 50 mcg/kg bolus over 10 minutes, followed by continuous infusion of 0.375-0.75 mcg/kg/min (max 1.13 mg/kg/day).
| Dosage form | INJECTABLE |
| Renal impairment | GFR 30-50 mL/min: reduce continuous infusion to 0.2-0.3 mcg/kg/min; GFR <30 mL/min: reduce to 0.1-0.2 mcg/kg/min. Bolus unchanged. |
| Liver impairment | No dosage adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Insufficient data for severe (Child-Pugh C). |
| Pediatric use | Loading dose: 50-75 mcg/kg IV over 10-60 minutes; maintenance: 0.25-0.75 mcg/kg/min continuous IV infusion. Some neonates may require lower dosing. |
| Geriatric use | Start at lower end of dosing range (0.375 mcg/kg/min) due to potential age-related renal impairment; monitor renal function and cardiac output. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Can cause ventricular arrhythmias and hypotension.
| FDA category | Animal |
| Breastfeeding | It is not known whether milrinone is excreted in human breast milk. No studies have determined the milk-to-plasma (M/P) ratio. Caution should be exercised when administered to a nursing woman. Due to the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. M/P ratio: unknown. |
| Teratogenic Risk |
■ FDA Black Box Warning
Not approved for long-term (≥48 hours) use; increases mortality risk in long-term treatment of heart failure.
| Common Effects | Arrhythmias |
| Serious Effects |
["Hypersensitivity to milrinone or any component","Severe aortic or pulmonic valvular disease","Acute myocardial infarction (relative; may increase mortality)","Severe hypotension"]
| Precautions | ["May cause ventricular arrhythmias (e.g., ventricular tachycardia, fibrillation)","Hypotension due to vasodilation; monitor blood pressure","Renal impairment requires dose adjustment","Electrolyte disturbances (hypokalemia, hypomagnesemia) increase arrhythmia risk","Monitor platelet count; may cause thrombocytopenia"] |
Loading safety data…
| Milrinone crosses the placenta. No adequate and well-controlled studies in pregnant women. In animal studies, milrinone was not teratogenic in rats or rabbits at doses up to 20 mg/kg/day (approximately 2.5 times the maximum recommended human dose based on body surface area). However, in rabbits, a dose of 20 mg/kg/day resulted in increased post-implantation loss. Therefore, milrinone should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. No specific trimester-specific risk data are available; thus, risk is considered potential throughout pregnancy. |
| Fetal Monitoring | Monitor maternal vital signs (blood pressure, heart rate, ECG) continuously during infusion. Assess for signs of hypotension, tachycardia, and arrhythmias. Monitor fluid and electrolyte status, renal function (urine output, serum creatinine), and hepatic function. Monitor fetal heart rate and uterine activity if used in pregnancy. Observe for maternal signs of hypersensitivity or thrombocytopenia. |
| Fertility Effects | In animal studies, milrinone had no effect on fertility in male and female rats at oral doses up to 20 mg/kg/day (approximately 2.5 times the maximum recommended human dose). No specific human fertility data are available. Therefore, based on animal data, milrinone is not expected to impair fertility in humans, but clinical data are lacking. |