Dopamine 40 mg/ml Sterile Concentrate

Dopamine is indicated in adults for the correction of haemodynamic imbalance present in:

Posology

Adults

Where appropriate, the circulating blood volume must be restored with a suitable plasma expander or whole blood, prior to administration of dopamine hydrochloride.

Begin infusion of dopamine hydrochloride solution at doses of 2.5 microgram/kg/min in patients who are likely to respond to modest increments of heart force and renal perfusion.

In more severe cases, administration may be initiated at a rate of 5 microgram/kg/min and increased gradually in 5- to 10 microgram/kg/min increments up to 20 to 50 microgram/kg/min as needed. If doses in excess of 50 microgram/kg/min are required, it is advisable to check urine output frequently.

Should urinary flow begin to decrease in the absence of hypotension, reduction of dopamine dosage should be considered. It has been found that more than 50% of patients have been satisfactorily maintained on doses less than 20 microgram/kg/min.

In patients who do not respond to these doses, additional increments of dopamine may be given in an effort to achieve adequate blood pressure, urine flow and perfusion generally.

Treatment of all patients requires constant evaluation of therapy in terms of blood volume, augmentation of cardiac contractility, and distribution of peripheral perfusion and urinary output.

Dosage of dopamine should be adjusted according to the patient's response, with particular attention to diminution of established urine flow rate, increasing tachycardia or development of new dysrhythmias as indications for decreasing or temporarily suspending the dosage.

Paediatric population

The safety and efficacy of dopamine in paediatric patients has not been established.

Elderly population

No variation in dosage is suggested for elderly patients. However, close monitoring is suggested for blood pressure, urine flow and peripheral tissue perfusion.

Method of administration

To be administered by intravenous infusion only after dilution with the appropriate diluents. For instructions on dilution of the medicinal product before administration, see section 6.6.

A suitable metering device is required in the infusion system to control the rate of flow, and this should be adjusted to the optimum patient response and monitored constantly in the light of the individual patient's response.

Dopamine is contraindicated in:

- hypersensitivity to the active substance(s) or to any of the excipients listed in section 6.1.

- patients with phaeochromocytoma or hyperthyroidism.

- the presence of uncorrected atrial or ventricular tachyarrhythmias or ventricular fibrillation.

- use with cyclopropane and halogenated hydrocarbon anaesthetics (see section 4.5).

Dopamine should not be used in the presence of uncorrected tachyarrhythmias or ventricular fibrillation. Nor should it be used in patients with phaeochromocytoma or hyperthroidism. Cyclopropane and halogenated hydrocarbon anaesthetics must be avoided.

Monoamine oxidase (MAO) inhibitors

Patients who have been treated with MAO inhibitors prior to dopamine should be given reduced doses; the starting dose should be one tenth (¹/₁₀th) of the usual dose.

Potassium-free solutions

Excess administration of potassium-free solutions may result in significant hypokalaemia.

The intravenous administration of these solutions can cause fluid and/or solute overloading resulting in dilution of serum electrolyte concentrations, overhydration, congested states or pulmonary oedema.

Hypovolaemia

Hypovolaemia should be corrected where necessary prior to dopamine infusion. Low doses should be used in shock due to acute myocardial infarction.

Decreased pulse pressure

If a disproportionate rise in diastolic pressure (i.e. a marked decrease in pulse pressure) is observed, the infusion rate should be decreased and the patients observed carefully for further evidence of predominant vasoconstriction activity, unless such an effect is desired.

Occlusive vascular disease

Patients with a history of peripheral vascular disease should be closely monitored for any changes in colour or temperature of the skin of the extremities. If change of skin colour or temperature occurs and is thought to be the result of compromised circulation to the extremities, the benefits of continued dopamine infusion should be weighed against the risk of possible necrosis. These changes may be reversed by decreasing the rate or discontinuing the infusion. IV administration of phentolamine mesylate 5-10 mg may reverse the ischaemia.

Extravasation

Dopamine hydrochloride in 5% dextrose injection should be infused into a large vein whenever possible to prevent the possibility of infiltration of perivascular tissue adjacent to the infusion site. Extravasation may cause necrosis and sloughing of the surrounding tissue. Ischaemia can be reversed by infiltration of the affected area with 10-15 ml of saline containing 5 to 10 mg phentolamine mesylate. A syringe with a fine hypodermic needle should be used to liberally infiltrate the ischaemic area as soon as extravasation is noted.

Diabetes

Dextrose solutions should be used with caution in patients with known subclinical or overt diabetes mellitus.

Renal and hepatic impairment

As the effect of dopamine on impaired renal and hepatic function is not known, close monitoring is advised.

Hypotension

Dopamine infusion should be withdrawn gradually, to avoid unnecessary hypotension.

Laboratory test interferences

Infusion of dopamine suppresses pituitary secretion of thyroid stimulating hormone, and prolactin.

Dopamine should not be added to alkaline diluents (see section 6.2).

Paediatric use

The safety and efficacy of dopamine in paediatric patients has not been established.

Excipient information

This medicine contains sodium metabisulfite (E 223) which may rarely cause severe hypersensitivity reactions and bronchospasm.

This medicine contains less than 1 mmol sodium (23 mg) per ampoule, that is to say essentially 'sodium-free'.

Anaesthetics

The myocardium is sensitised by the effect of dopamine, cyclopropane or halogenated hydrocarbon anaesthetics, and these must be avoided (see section 4.3). This interaction applies both to pressor activity and cardiac beta adrenergic stimulation.

Alpha and Beta Blockers

The cardiac effects of dopamine are antagonised by β -adrenergic blocking agents such as propranolol and metoprolol, and the peripheral vasoconstriction caused by high doses of dopamine is antagonised by α adrenergic blocking agents. Dopamine-induced renal and mesenteric vasodilation is not antagonised by either α or β -adrenergic blocking agents, but, in animals, is antagonised by haloperidol or other butrophenones, phenothiazines, and opiates.

Monoamine Oxidase (MAO) Inhibitors

MAO inhibitors potentiate the effect of dopamine and its duration of action. Patients who have been treated with MAO inhibitors prior to administration of dopamine will therefore require a substantially reduced dosage. (The starting dose should be reduced to at least ¹/₁₀th of the usual dose.

Phenytoin

Administration of IV phenytoin to patients receiving dopamine has resulted in hypotension and bradycardia; some clinicians recommend that phenytoin be used with extreme caution, if at all, in patients receiving dopamine.

Diuretic agents

Dopamine may increase the effect of diuretic agents.

Ergot alkaloids

The ergot alkaloids should be avoided because of the possibility of excessive vasoconstriction.

Tricyclic antidepressants and guanethidine

Tricyclic antidepressants and guanethidine may potentiate the pressor response to dopamine.

Pregnancy

Animal studies have shown no evidence of teratogenic effects with dopamine. However, the effect of dopamine on the human foetus is unknown. Therefore the drug should be used in pregnant women only when the expected benefits outweigh the potential risk to the foetus.

Breast-feeding

It is not known if dopamine is excreted in breast milk, nor is the effect on the infant known.

The effect of dopamine hydrochloride on the ability to drive or use machines has not been systematically evaluated.

Adverse reactions to dopamine are related to its pharmacological action.

Frequencies are defined as: very common (>1/10), common (>1/100 to <1/10), uncommon (>1/1,000 to <1/100), rare (>1/10,000 to <1/1,000), very rare (<1/10,000) , not known (cannot be estimated from the available data).

¹ Serious or Life-threatening Reactions: Gangrene of the feet has occurred following doses of 10-14 microgram/kg/min and higher in a few patients with pre-existing vascular disease.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation 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 via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App store.

Excessive elevation of blood pressure and vasoconstriction can occur due to the alpha adrenergic actions of dopamine, especially in patients with a history of occlusive vascular disease. If desired, this condition can be rapidly reversed by dose reduction or discontinuing the infusion, since dopamine has a half-life of less than 2 minutes in the body.

Should these measures fail, an infusion of an alpha-adrenergic blocking agent, e.g., phentolamine mesylate should be considered.

Dopamine at the infusion site can cause local vasoconstriction hence the desirability of infusing into a large vein. The resulting ischaemia can be reversed by infiltration of the affected area with 10-15 ml of saline containing 5 mg to 10 mg phentolamine mesylate. A syringe with a fine hypodermic needle should be used to liberally infiltrate the ischaemic area as soon as extravasation is noted.

Pharmacotherapeutic group: adrenergic and dopaminergic agents, ATC code: C01CA04

Mechanism of action

Dopamine stimulates adrenergic receptors of the sympathetic nervous system. The drug has principally a direct stimulatory effect on β ₁-adrenergic receptors, but also appears to have an indirect effect by releasing norepinephrine from its storage sites. Dopamine also appears to act on specific dopaminergic receptors in the renal, mesenteric, coronary, and intracerebral vascular beds to cause vasodilation. The drug has little or no effect on β ₂-adrenergic receptors.

Pharmacodynamic effects

In IV doses of 0.5-2 microgram/kg per minute, the drug acts predominantly on dopaminergic receptors; in IV doses of 2-10 microgram/kg per minute, the drug also stimulates β ₁-adrenergic receptors. In higher therapeutic doses, α -adrenergic receptors are stimulated and the net effect of the drug is the result of α -adrenergic, β ₁-adrenergic, and dopaminergic stimulation. The main effects of dopamine depend on the dose administered. In low doses, cardiac stimulation and renal vascular dilation occur and in larger doses vasoconstriction occurs. It is believed that α -adrenergic effects result from inhibition of the production of cyclic adenosine -31, 51-monophosphate (cAMP) by inhibition of the enzyme adenyl cyclase, whereas β -adrenergic effects result from stimulation of adenyl cyclase activity.

Absorption:

Orally administered dopamine is rapidly metabolised in the G.I. tract. Following IV administration, the onset of action of dopamine occurs within 5 minutes, and the drug has duration of action of less than 10 minutes.

Distribution:

The drug is widely distributed in the body but does not cross the blood-brain barrier to a substantial extent. It is not known if dopamine crosses the placenta.

Elimination:

Dopamine has a plasma half-life of about 2 minutes. Dopamine is metabolised in the liver, kidneys, and plasma by monoamine oxidase (MAO) and catechol-O-methyltransferase to the inactive compounds homovanillic acid (HVA) and 3, 4-dihydroxyphenylacetic acid. In patients receiving MAO inhibitors, the duration of action of dopamine may be as long as 1 hour. About 25% of a dose of dopamine is metabolised to norepinephrine within the adrenergic nerve terminals.

Dopamine is excreted in urine principally as HVA and its sulfate and glucuronide conjugates and as 3, 4-dihydroxyphenylacetic acid. A very small fraction of a dose is excreted unchanged. Following administration of radio labelled dopamine, approximately 80% of the radioactivity reportedly is excreted in urine within 24 hours.

There is no pre-clinical data of relevance to the prescriber which are additional to that already included in other sections of the SPC.

Sodium metabisulfite (E 223)

Water for injections

1_N Sodium Hydroxide (for pH adjustment)

1_N Hydrochloric Acid (for pH adjustment)

Dopamine Sterile Concentrate should not be added to any alkaline intravenous solutions, i.e. sodium bicarbonate. Any solution which exhibits physical or chemical incompatibility through a colour change or precipitate should not be administered.

It is suggested that admixtures containing gentamicin sulfate, cephalothin sodium, cephalothin sodium neutral or oxacillin sodium should be avoided unless all other viable alternatives have been exhausted.

Admixtures of ampicillin and dopamine in 5% glucose solution are alkaline and incompatible and result in decomposition of both drugs. They should not be admixed.

Admixtures of dopamine, amphotericin B in 5% glucose solution are incompatible as a precipitate forms immediately on mixing.

As packaged for sale: 3 years.

Following dilution in the recommended diluents (see section 6.6), chemical and physical in-use stability has been demonstrated for 48 hours at a temperature not above 25° C.

However, from a microbiological point of view, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to used are the responsibility of the user and would normally not be longer than 24 hours at 2-8° C unless dilution has taken place in controlled and validated aseptic conditions.

Do not store above 30° C. Keep container in the outer carton in order to protect from light.

For storage conditions after dilution of the medicinal product, see section 6.3.

Clear, type I, glass ampoules.

Not all pack sizes may be marketed.

For single use. Any unused medicinal product or waste material should be disposed of in accordance with local requirements.

Do not use if the solution is discoloured.

Preparation of Infusion Solutions

Dilution:

Aseptically transfer Dopamine Sterile Concentrate into the IV solution as shown in the following table:-

Dopamine hydrochloride can be diluted with:-

Sodium chloride (0.9%) intravenous infusion

Dextrose (5%), sodium chloride (0.45%) solution

Sodium lactate intravenous infusion, compound (Hartmann's Solution for Injection)