Posology
Milrinone therapy should begin as an initial weight dependent dose reaching saturation and subsequently followed by a continuous, efficacy based maintenance dose according to the guidelines below.
Initial dose
The initial dose is 50 micrograms (0.05 mg) of milrinone/kg. It is administered slowly over a period of 10 minutes. This is usually followed by a continuous maintenance infusion. (Table 1)
Maintenance dose
The maintenance dose is generally 0.5 micrograms of milrinone /kg /minute. However, it may be between 0.375 micrograms of milrinone/kg/minute and 0.75 micrograms of milrinone/kg/minute. (Table 2)
The level of maintenance dose should be selected based on the hemodynamic effect and clinical efficacy.
The daily dose should not exceed 1.13 mg milrinone/kg.
Table 1. Initial dose (Concentration 1 mg / ml)
Body weight of the patient (kg) compared to the amount of initial dose of milrinone
| BW (kg) | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | 110 |
| Ml | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 | 4.0 | 4.5 | 5.5 | 6.0 |
Table 2. Maintenance dose (for continuous use)
| | Dosage (microgram / kg BW/ min) | Daily dose (24 hours)* mg / kg BW |
| minimum dose | 0.375 | 0.59 |
| standard dose | 0.50 | 0.77 |
| maximum dose | 0.75 | 1.13 |
* The "daily dose (24 hours)" (in mg/kg BW) is calculated from the respective dosage (minimum, standard, maximum dose) plus initial dose (0.05 mg/kg BW)
To administer the maintenance dose, prepare an infusion solution containing 200 micrograms of milrinone/ml. It is prepared by adding 40 ml of a carrier solution to 10 ml undiluted milrinone solution for injection. The diluents/carrier solutions can be 0.9% Sodium Chloride Infusion and 5% Glucose Infusion.
Depending on the required maintenance dose (in micrograms/kg/minute), the following infusion rates (in milliliters/kg/hour) are obtained for the prepared infusion solution at a concentration of 200 microgram/ml (see Table 3).
Table 3: Conversion of the maintenance dose into the corresponding infusion rate
| Maintenance Dose (microgram/kg/minute) | Maintenance Dose (microgram/kg/hour) | Infusion rate* (milliliter/kg/hour) |
| 0.375 | 22.5 | 0.11 |
| 0.400 | 24.0 | 0.12 |
| 0.500 | 30.0 | 0.15 |
| 0.600 | 36.0 | 0.18 |
| 0.700 | 42.0 | 0.21 |
| 0.750 | 45.0 | 0.22 |
* calculated for an infusion solution containing 200 micrograms of milrinone per milliliter.
Infants and Children
The published studies revealed that the following doses were used in infants and children:
- Intravenous initial dose: 50 to 75 microgram/kg over 30 to 60 minutes.
- Continuous intravenous infusion: administration of dose has to be carried out, with due consideration given to the hemodynamic response and possible onset of side effects; the infusion rate is 0.25 to 0.75 microgram/kg/ min over a period of up to 35 hours.
In clinical studies in infants and children under 6 years with low-cardiac output syndrome after surgical correction of congenital heart disease, the administration of an initial dose of 75 microgram/kg over 60 minutes and subsequent maintenance infusion of 0.75 microgram/kg/min over 35 hours reduced the risk of a low-cardiac output syndrome.
The results of the pharmacokinetic studies (see section 5.2) must be taken into account.
Children with renal impairment:
Since no data is available, the use of milrinone in children with impaired renal function is not recommended (see section 4.4 for more information).
Patent Ductus arteriosus:
When considering the use or risk of milrinone in preemies or neonates, infants with patent Ductal arteriosus, the therapeutic benefit should be weighed against the potential risks (see sections 4.4, 4.8, 5.2 and 5.3).
Elderly patients
Based on current knowledge, it is to be expected that in case of normal renal function no special dosage recommendations are necessary for this patient group.
Patients with renal impairment:
In patients with renal impairment, excretion of milrinone is limited. Therefore, a dose adjustment is required. The following recommendation is based on data from patients with renal impairment without cardiac insufficiency, in whom a significant prolongation of terminal half-life of milrinone was observed.
The initial dose is unchanged. The maintenance dose should be reduced depending on the extent of functional impairment (see Table 4).
Table 4: Conversion of the reduced maintenance dose in renal impairment patients to the corresponding infusion rate
| Creatinine clearance (ml/min/1.73 m2), | Maintenance dose (microgram/kg /minute) | Maintenance dose (microgram/kg/hour) | Infusion rate* (milliliter/kg/hour). |
| 5 | 0.20 | 12.0 | 0.06 |
| 10 | 0.23 | 13.8 | 0.07 |
| 20 | 0.28 | 16.8 | 0.08 |
| 30 | 0.33 | 19.8 | 0.10 |
| 40 | 0.38 | 22.8 | 0.11 |
| 50 | 0.43 | 25.8 | 0.13 |
* calculated for an infusion solution containing 200 micrograms of milrinone per milliliter
Method of administration
Milrinone is administered by slow intravenous injection or intravenous infusion.
Milrinone must not be mixed with carrier solutions other than those mentioned above (see also section 6.2). Depending on the fluid requirements of the patient, solutions of different concentrations can be used.
If no immediate usage is possible, the diluted solution should not be used after 24 hours (see also section 6.3).
For injection, the largest possible vein should be punctured to avoid local irritation. An extravascular injection must be avoided. The duration of treatment should not exceed 48 hours due to a lack of evidence of safety and efficay in long-term treatment of congestive heart failure. In children, the treatment duration is up to 35 hours.
So far, results have been available on the treatment of heart failure with milrinone only with concomitant administration of a diuretic.