Consumer medicine information

Primacor Injection

Milrinone

BRAND INFORMATION

Brand name

Primacor

Active ingredient

Milrinone

Schedule

SUMMARY CMI

Primacor Injection

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Primacor?

Primacor contains the active ingredient Milrinone Lactate. Primacor is used for the short term treatment of severe congestive heart failure.

For more information, see Section 1. Why am I using Primacor? in the full CMI.

2. What should I know before I use Primacor?

Do not use if you have ever had an allergic reaction to Primacor or any of the ingredients listed at the end of the CMI.

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Primacor? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Primacor and affect how it works.

A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Primacor?

Primacor is usually given to you in hospital. It is given to you as a series of injections.

More instructions can be found in Section 4. How do I use Primacor? in the full CMI.

5. What should I know while using Primacor?

Things you should do	Remind any doctor, dentist or pharmacist you visit that you are using Primacor.
Things you should not do	You should not use Primacor if you are allergic to milrinone, similar medicines, or any of the ingredients listed at the end of this leaflet.
Driving or using machines	Be careful before you drive or use any machines or tools until you know how Primacor affects you.
Drinking alcohol	NA
Looking after your medicine	If you need to store Primacor make sure it is in a cool dry place where the temperature does not exceed 30°C. Do not refrigerate.

For more information, see Section 5. What should I know while using Primacor? in the full CMI.

6. Are there any side effects?

Effects you may feel during the Primacor injection include an irregular heartbeat, low blood pressure, light headedness, dizziness, chest pain, headaches, skin rashes. For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

FULL CMI

Primacor Injection

Active ingredient: Milrinone Lactate

Consumer Medicine Information (CMI)

This leaflet provides important information about using Primacor. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Primacor.

Where to find information in this leaflet:

1. Why am I using Primacor?
2. What should I know before I use Primacor?
3. What if I am taking other medicines?
4. How do I use Primacor?
5. What should I know while using Primacor?
6. Are there any side effects?
7. Product details

1. Why am I using Primacor?

Primacor contains the active ingredient milrinone lactate.

Primacor is used for the short term treatment of severe congestive heart failure. This is a condition where the heart fails to pump enough blood around the body. The symptoms of this condition include weakness, breathlessness, fluid build-up in the tissues and a blue discolouration of the skin.

Primacor also helps to maintain the output of blood from the heart in patients following heart surgery.

Primacor helps improve the efficiency with which your heart pumps blood around your body.

Primacor works by increasing the force by which your heart muscles work and opening up your blood vessels to allow blood to flow more freely.

2. What should I know before I use Primacor?

Warnings

Do not use Primacor if:

you are allergic to milrinone lactate, or any of the ingredients listed at the end of this leaflet.
Always check the ingredients to make sure you can use this medicine.
you have certain severe problems (obstructive aortic or pulmonary valvular disease).
you are pregnant or breastfeeding, unless you and your doctor have discussed the risks and benefits involved.

Check with your doctor if you:

have any other medical conditions
take any medicines for any other condition
suffer from kidney disease
already suffer from another heart condition
are allergic to other drugs used to treat congestive heart failure.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant.

Talk to your doctor if you are breastfeeding or intend to breastfeed.

Primacor should not be given if you are pregnant or breastfeeding, unless you and your doctor have discussed the risks and benefits involved.

It is not known whether Primacor can harm your baby or whether it is found in breast milk.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Primacor.

4. How do I use Primacor?

How much to take / use

Primacor is usually given to you in hospital. It is given to you as a series of injections as follows:

Adults:

Initial Dose

One injection given slowly over a 10 minute period.

Second Dose

The Primacor will be diluted with intravenous fluids and injected slowly into a vein. This "infusion" may last up to 48 hours. The dose used will depend upon the severity of your condition.

Primacor is not recommended for use in children.

When to take / use Primacor

Primacor is usually given to you in hospital. It is given to you as a series of injections.

If you use too much Primacor

If you think that you have used too much Primacor, you may need urgent medical attention.

Too high a dose of Primacor may cause low blood pressure. If this occurs, the dose of Primacor may be reduced or the infusion temporarily stopped.

You should immediately:

phone the Poisons Information Centre
(by calling 13 11 26) in Australia, or
phone the National Poisons Centre on 0800 POISON (0800 764766) in New Zealand, or
contact your doctor, or
go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

5. What should I know while using Primacor?

Things you should do

Call your doctor straight away if you:

do not feel well while Primacor is being given to you.

Remind any doctor, dentist or pharmacist you visit that you are using Primacor.

Things you should not do

You should not use Primacor if you are allergic to milrinone, similar medicines, or any of the ingredients listed at the end of this leaflet.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Primacor affects you.

Looking after your medicine

Primacor will usually be stored and administered at the hospital.

If you need to store Primacor make sure it is in a cool dry place where the temperature does not exceed 30°C.
Do not refrigerate.
Follow the instructions in the carton on how to take care of your medicine properly.

Keep it where young children cannot reach it.

This is not all the information available on Primacor. If you have any more questions or are not sure about anything ask your doctor, pharmacist or nurse.

6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Primacor helps most people with severe congestive heart failure, but it may have unwanted effects in some people.

All medicines have side effects. Sometimes they are serious, most of the time they are not.

Less serious side effects

Less serious side effects

What to do

Effects you may feel during the Primacor injection include:

an irregular heartbeat
low blood pressure
light headedness, dizziness
chest pain
headaches
skin rashes

Allergy related:

rash
asthma attack
hay fever.

Speak to your doctor if you have any of these less serious side effects and they worry you.

Other side effects not listed above may also occur in some people.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems in Australia and nzphvc.otago.ac.nz/reporting in New Zealand. By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Primacor contains

Active ingredient (main ingredient)	Milrinone Lactate 1 mg/mL
Other ingredients (inactive ingredients)	Glucose Water for Injections Lactic acid Sodium hydroxide
Potential allergens	Not Applicable

Do not take this medicine if you are allergic to any of these ingredients.

What Primacor looks like

Primacor is a clear colourless to pale yellow solution.

A box contains 10 ampoules.

Primacor 10mg/10mL injection: AUST R 10372

Who distributes Primacor

Primacor is supplied in Australia by:

sanofi-aventis australia pty ltd
12-24 Talavera Road
Macquarie Park, NSW 2113
Freecall No: 1800 818 806

Primacor is supplied in New Zealand by:

sanofi-aventis new zealand limited
James & Wells Tower
56 Cawley Street
Ellerslie, Auckland
Freecall No: 0800 283 684

This leaflet was last revised in May 2021.

primacor-ccdsv7-cmiv3-28may21

Published by MIMS July 2021

BRAND INFORMATION

Brand name

Primacor

Active ingredient

Milrinone

Schedule

1 Name of Medicine

Milrinone lactate.

2 Qualitative and Quantitative Composition

Sterile, single dose ampoules.

Single-dose ampoules of 10 mL contain in each mL milrinone lactate equivalent to 1 mg milrinone, and 47 mg glucose monohydrate, in water for injections. The pH is adjusted to between 3.2 and 4.0 with lactic acid or sodium hydroxide. The total concentration of lactic acid can vary between 0.95 mg/mL and 1.29 mg/mL. These ampoules require preparation of dilutions prior to administration to patients intravenously.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Sterile aqueous solution of the lactate salt of milrinone for injection or infusion intravenously.
Colourless to pale yellow in solution.

4 Clinical Particulars

4.1 Therapeutic Indications

Primacor Injection is indicated for the short-term (48 hours) intravenous therapy of severe congestive heart failure patients in intensive care and coronary care units not responding to other therapy (e.g. digoxin, diuretics, vasodilators including ACE inhibitors). The majority of experience with intravenous Primacor has been in patients receiving digoxin and diuretics.
Primacor is also indicated for low output states following cardiac surgery, including weaning from cardiopulmonary bypass pump.

4.2 Dose and Method of Administration

Primacor Injection should be administered with a loading dose followed by a continuous infusion (maintenance dose) according to the following guidelines:

Loading dose.

50 microgram/kg. Administer slowly over 10 minutes.

Maintenance dose.

See Table 1.

Note.

Administer as a continuous intravenous infusion.
The infusion rate should be adjusted according to haemodynamic and clinical response. Patients should be closely monitored. Most patients show an improvement in haemodynamic 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 haemodynamic effect and should not exceed 1.13 mg/kg/day. Duration of therapy should depend upon patient responsiveness.
Infusion should be commenced as soon as practicable after preparation of the mixture in order to reduce microbiological hazards. Preparations not used within 24 hours should be discarded.
Intravenous infusions of Primacor injection should be administered as described in Table 2.

0.45% saline, 0.9% saline and 5% glucose may be used as diluents.

Note.

Intravenous drug products should be inspected visually and should not be used if particulate matter or discolouration is present.
Primacor should not be diluted in sodium bicarbonate intravenous solution. See Section 6.2 Incompatibilities.

Dosage adjustment in renally impaired patients.

Data obtained from patients with severe renal impairment (creatinine clearance = 0 to 30 mL/min) but without congestive heart failure have demonstrated that the presence of renal impairment significantly increases the terminal elimination half-life of milrinone. Reductions in the starting infusion rate may be necessary in patients with renal impairment. For patients with clinical evidence of renal impairment, the recommended infusion rate can be obtained from Table 3.

4.3 Contraindications

Primacor Injection should not be used in patients with severe obstructive aortic or pulmonary valvular disease, or hypertrophic subaortic stenosis. Primacor injection should not be used in lieu of surgical relief of the obstruction. Like other inotropic agents, Primacor may aggravate outflow tract obstruction in these conditions.
Hypersensitivity to milrinone, other bipyridines or any other ingredient in the formulation.

4.4 Special Warnings and Precautions for Use

Myocardial ischaemia or infarction may occur in patients following cardiac surgery. Should these events occur, care should be taken with the use of Primacor as information on the safety of Primacor under these circumstances is limited.
Use of inotropic agents such as milrinone during the acute phases of a myocardial infarction may lead to an undesirable increase in myocardial oxygen consumption (MVO₂). Milrinone has not increased MVO₂ in patients with chronic heart failure, however, until further clinical experience with this class of drugs is gained, Primacor is not recommended during the acute phase of postmyocardial infarction.
Supraventricular and ventricular arrhythmias have been observed in the high risk population treated. In some patients, Primacor has been shown to increase ventricular ectopy, including nonsustained ventricular tachycardia. The potential for arrhythmia, present in congestive heart failure itself, may be increased by many drugs or combinations of drugs. Patients receiving Primacor injection should be closely monitored (including heart rate, clinical state, electrocardiogram, fluid balance, electrolytes and renal function) during infusion.
Primacor produces a slight shortening in A-V node conduction time, indicating a potential for an increased ventricular response rate in patients with atrial flutter/ fibrillation which is not being controlled with digitalis therapy. In these patients, prior digitalisation or treatment with other agents to prolong A-V node conduction time should be considered.
Primacor injection may induce hypotension as a consequence of its vasodilatory action. Caution should therefore be exercised in patients with hypotension prior to treatment or in those showing excessive decreases in blood pressure during therapy with Primacor injection. In such cases, the infusion should be stopped until the hypotensive effect has been resolved, then resumed at a lower rate if resumption is considered necessary.
If prior vigorous diuretic therapy is suspected to have caused significant decreases in cardiac filling pressure, Primacor injection should be cautiously administered with monitoring of blood pressure, heart rate and clinical symptomatology.
There is no experience in controlled trials with infusions of milrinone for periods exceeding 48 hours. Cases of infusion site reaction have been reported with intravenous milrinone therapy (see Section 4.8 Adverse Effects (Undesirable Effects)). Consequently, careful monitoring of the infusion site should be maintained so as to avoid possible extravasation.

Use in hepatic impairment.

No data available.

Use in renal impairment.

In patients with severe renal impairment the dose should be adjusted (see Section 4.2 Dose and Method of Administration).

Use in the elderly.

There are no special dosage recommendations for the elderly patient.
Ninety percent of all patients administered Primacor Injection in clinical studies were within the age range of 45-70 years, with a mean age of 61 years. Patients in all age groups demonstrated clinically and statistically significant responses. No age-related effects on the incidence of adverse reactions have been observed.
Controlled pharmacokinetic studies have not disclosed any age-related effects on the distribution and elimination of Primacor.

Paediatric use.

Safety and effectiveness in children have not been established.

Effects on laboratory tests.

Fluid and electrolyte changes, as well as serum creatinine levels and renal function should be carefully monitored during Primacor therapy. Improvement in cardiac output with resultant diuresis may necessitate a reduction in the dose of diuretic. Potassium loss due to excessive diuresis may predispose digitalised patients to arrhythmias. Therefore, hypokalaemia should be corrected by potassium supplementation in advance of or during Primacor use.

4.5 Interactions with Other Medicines and Other Forms of Interactions

No untoward clinical manifestations have been observed in patients in whom Primacor injection was used concurrently with the following drugs: digitalis glycosides, lidocaine (lignocaine), quinidine, hydralazine, prazosin, isosorbide dinitrate, glyceryl trinitrate, chlorthalidone, furosemide (frusemide), hydrochlorothiazide, spironolactone, captopril, heparin, warfarin, diazepam, insulin and potassium supplements.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

In reproductive performance studies in rats, Primacor had no effect on male or female fertility at oral doses up to 32 mg/kg/day.
(Category B3)
Oral administration of Primacor 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. Primacor did not appear to be teratogenic when administered intravenously to pregnant rats at doses up to 3 mg/kg/day or pregnant rabbits at doses up to 12 mg/kg/day, although an increased resorption rate was apparent at dose levels above 3 mg/kg/day (intravenous) in the latter species. There are no adequate and well controlled studies in pregnant women. Primacor should be used during pregnancy only if the potential benefit justifies the potential risk to the foetus.
Caution should be exercised when Primacor is administered to nursing women since it is not known whether it is excreted in human milk.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

Cardiovascular effects.

Ventricular arrhythmias were reported in 12.1% of patients receiving Primacor injection: ventricular ectopic activity 8.5%, nonsustained ventricular tachycardia 2.8%, sustained ventricular tachycardia 1% and ventricular fibrillation 0.2%. Holter recordings have demonstrated in some patients that injection of Primacor increases ventricular ectopy, including nonsustained ventricular tachycardia. Life threatening arrhythmias are infrequent and when present have been associated with certain underlying factors, such as pre-existing arrhythmias, metabolic abnormalities (e.g. hypokalaemia), abnormal digoxin levels and catheter insertion.
Very rarely (< 0.01%) cases of torsades de pointes have been reported.
Supraventricular arrhythmias were reported in 3.8% of the patients receiving Primacor injection. The incidence of both supraventricular and ventricular arrhythmias has not been related to the dose or plasma level of milrinone. There is no evidence for a patient subset which is at higher risk for ventricular arrhythmias.
Other cardiovascular adverse reactions include hypotension 2.9% and angina/ chest pain 1.2%.

CNS effects.

Headaches, mostly mild to moderate in severity, have been reported in 2.9% of patients receiving Primacor injection.

Skin.

Dermatological reactions such as rashes have been observed in < 0.01% of patients. Cases of infusion site reaction have been reported.

Liver.

Abnormal liver function tests have been observed in < 1% of patients.

Congenital, familial, and genetic disorders.

Patent ductus arteriosus has been reported.

Renal and urinary disorders.

Renal failure, secondary to a concomitant hypotension, has been reported.

Other effects.

Other adverse reactions reported, all with an incidence of less than 1% but not definitely related to the administration of Primacor injection, include hypokalaemia, tremor and thrombocytopenia. Very rarely (< 0.01%) bronchospasm and anaphylactic shock have occurred.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems (Australia) and https://nzphvc.otago.ac.nz/reporting/ (New Zealand).

4.9 Overdose

Doses of Primacor injection may induce hypotension because of its vasodilator effect. If this occurs, administration of Primacor should be reduced or temporarily discontinued until the patient's condition stabilises. No specific antidote is known, but general measures for circulatory support should be taken.
For information on the management of overdose, contact the Poison Information Centre on 131126 (Australia), or the National Poisons Centre on 0800 POISON (0800 764766) (New Zealand).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Pharmacotherapeutic group: Cardiac stimulants excluding cardiac glycosides, Phosphodiesterase inhibitors, ATC code: C01CE02.

Mechanism of action.

Primacor is a positive inotrope and vasodilator, with little chronotropic activity, different in structure and mode of action from either the digitalis glycosides or catecholamines.
Primacor at relevant inotropic and vasorelaxant concentrations, is a selective inhibitor of peak III cAMP phosphodiesterase isozyme in cardiac and vascular muscle. This inhibitory action is consistent with cAMP mediated increases in intracellular ionised calcium and contractile force in cardiac muscle, as well as with cAMP dependent contractile protein phosphorylation and relaxation in vascular muscle. Additional experimental evidence also indicates that Primacor is not a β-adrenergic agonist, and unlike digitalis glycosides, it does not inhibit Na⁺/K⁺ ATPase activity.
Clinical studies in patients with congestive heart failure have shown that Primacor injection produces dose related and plasma level related increases in the maximum rate of increase of left ventricular pressure (dP/dt_max). Studies in normal subjects have shown that Primacor injection produces increases in the slope of the left ventricular pressure dimension relationship, indicating a direct inotropic effect of the drug.
Primacor injection also produces dose related and plasma concentration related increases in forearm blood flow in patients with congestive heart failure, indicating a direct arterial vasodilator activity of the drug.
Both the inotropic and vasodilatory effects have been observed over the therapeutic range of plasma milrinone concentrations of 100 nanogram/mL to 300 nanogram/mL.
In addition to increasing myocardial contractility, Primacor improves diastolic function as evidenced by improvements in left ventricular diastolic relaxation.

Pharmacodynamics.

In patients with depressed myocardial function, Primacor injection produces a prompt increase in cardiac output and decreases in pulmonary capillary wedge pressure and vascular resistance, without a significant increase in heart rate or myocardial oxygen consumption.
These haemodynamic improvements are both dose and plasma milrinone concentration related. Haemodynamic improvement during intravenous therapy with Primacor was accompanied by clinical symptomatic improvement, as measured by changes in New York Heart Association classification. The great majority of patients experience improvements in haemodynamic function within 5 to 15 minutes of the initiation of therapy.
In studies in congestive heart failure patients, Primacor when administered as a loading injection followed by a maintenance infusion produced significant mean initial increases in cardiac index as shown in Table 4.

Over the same range of loading injections and maintenance infusions, pulmonary capillary wedge pressure significantly decreased by 20%, 23% and 36%, respectively, while systemic vascular resistance significantly decreased by 17%, 21% and 37%. The heart rate was generally unchanged (increases of 2%, 3% and 10%, respectively). Mean arterial pressure fell by up to 5%, at the two lower dose regimens, but by 17% at the highest dose. Patients evaluated for 48 hours maintained improvements in haemodynamic function, with no evidence of diminished response (tachyphylaxis). A smaller number of patients have received infusions of Primacor for periods up to 72 hours without evidence of tachyphylaxis.
Primacor injection has a favourable inotropic effect in fully digitalised patients without causing signs of glycoside toxicity. Theoretically, in cases of atrial flutter/ fibrillation, it is possible that Primacor injection may increase ventricular response rate because of its slight enhancement of A-V node conduction. In these cases, digitalis should be considered prior to the institution of therapy of Primacor.
Improvement in left ventricular function and relief of congestive heart failure symptoms in patients with ischaemic heart disease have been observed. The improvement has occurred without inducing symptoms or ECG signs in myocardial ischaemia.
The steady-state milrinone plasma levels after approximately 6-12 hours of unchanging maintenance infusion of 0.50 microgram/kg/min are approximately 200 nanogram/mL. Near maximal favourable effects of Primacor on cardiac output and pulmonary capillary wedge pressure are seen at plasma milrinone concentrations in the 150 nanogram/mL to 250 nanogram/mL range.

Clinical trials.

In a double blind, placebo controlled study in patients being weaned off cardiopulmonary bypass, 100% of patients taking Primacor were successfully weaned off bypass compared to 33% of the placebo arm patients. All patients who initially failed blinded placebo treatment were successfully weaned from cardiopulmonary bypass support following administration with open label Primacor.
In acute states following cardiac surgery, it is unlikely that treatment need be maintained for more than 12 hours.

5.2 Pharmacokinetic Properties

Following intravenous loading injections of 12.5 to 125.0 microgram/kg to congestive heart failure patients, Primacor has a volume of distribution of 0.38 litre/kg, a mean terminal elimination half-life of 2.3 hours, and a clearance of 0.13 litre/kg/hr. Following intravenous infusions of 0.20 to 0.70 microgram/kg/min to congestive heart failure patients, Primacor has a volume of distribution of about 0.45 litre/kg, a mean terminal elimination half-life of 2.4 hours, and a clearance of 0.14 litre/kg/hr. These pharmacokinetic parameters were not dose dependent, and the area under the plasma concentration versus time curve following loading injections was significantly dose dependent.
Primacor has been shown (by equilibrium dialysis) to be approximately 70% bound to human plasma protein.
The primary route of excretion of Primacor in man is via the urine, with much smaller amounts recovered in the faeces. The major urinary excretion products in man are milrinone (83%) and its o-glucuronide metabolite (12%).
Elimination in normal subjects via the urine is rapid, with approximately 60% recovered within the first two hours following dosing and approximately 90% recovered within the first eight hours following dosing. The mean renal clearance of Primacor is approximately 0.3 litre/min while that of the metabolites is even greater, indicative of active secretion.

5.3 Preclinical Safety Data

Genotoxicity.

Whereas the Chinese Hamster Ovary Chromosome Aberration Assay was positive in the presence of a metabolic activation system, results from the Ames Test, the Mouse Lymphoma Assay, the Micronucleus Test and the in vivo Rat Bone Marrow Metaphase Analysis indicated an absence of mutagenic potential.

Carcinogenicity.

Twenty-four months of oral administration of Primacor to mice at doses up to 40 mg/kg/day was unassociated with evidence of carcinogenic potential. Neither was there evidence of carcinogenic potential when Primacor was orally administered to rats at doses up to 5 mg/kg/day for 24 months or at 25 mg/kg/day for up to 18 months in males and 20 months in females.

Animal toxicity.

Oral and intravenous administration of toxic dosages of Primacor to rats and dogs resulted in myocardial degeneration/fibrosis and endocardial haemorrhage, principally affecting the left ventricular papillary muscles. Coronary vascular lesions characterised by periarterial oedema and inflammation have been observed in dogs only. The myocardial/endocardial changes are similar to those produced by β-adrenergic receptor agonists such as isoprenaline, while the vascular changes are similar to those produced by minoxidil and hydralazine.

6 Pharmaceutical Particulars

6.1 List of Excipients

Glucose monohydrate, lactic acid or sodium hydroxide (for pH adjustment), and water for injections.

6.2 Incompatibilities

There is an immediate chemical interaction which is evidenced by the formation of a precipitate when furosemide (frusemide) is injected into an intravenous line of an infusion of Primacor. Therefore furosemide (frusemide) or bumetanide should not be administered in intravenous lines containing Primacor.
Primacor should not be diluted in sodium bicarbonate intravenous solution.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.
Diluted preparations not used within 24 hours should be discarded.

6.4 Special Precautions for Storage

Store below 30°C. Avoid freezing.

6.5 Nature and Contents of Container

Primacor injection is supplied in single dose (1 mg/mL) Injection ampoules (10 mL: 10s).

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Primacor Injection, brand of milrinone lactate, is a member of a new class of bipyridine inotropic/vasodilator agents with phosphodiesterase activity, distinct from digitalis glycosides or catecholamines. Primacor (milrinone lactate) is designated chemically as 1,6-dihydro-2-methyl-6-oxo-[3,4'- bipyridine]-5-carbonitrile lactate and has the structure below.
Milrinone is an off-white to tan crystalline compound with a molecular weight of 211.2 and an empirical formula of C₁₂H₉N₃O. It is stable and colourless to pale yellow in solution.

Chemical structure.

CAS number.

Milrinone: 78415-72-2.
Milrinone lactate: 100286-97-3.

7 Medicine Schedule (Poisons Standard)

Prescription Only Medicine.

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Milrinone

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