METARAMINOL 10MG/ML SOLUTION FOR INJECTION OR INFUSION
Active substance(s): METARAMINOL TARTRATE
NAME OF THE MEDICINAL PRODUCT
Metaraminol 10mg/mL Solution for Injection or Infusion.
QUALITATIVE AND QUANTITATIVE COMPOSITION
Each 1 mL of solution contains 10mg of metaraminol (as tartrate).
Excipients of known effect:
Each 1 mL of solution contains 98.3 micromol (2.26 mg) sodium.
For the full list of excipients, see section 6.1.
Solution for injection or infusion.
Glass ampoule containing a clear colourless solution with pH of 3.2 to 4.5 and
osmolarity of 305mOsm/litre.
For the treatment of acute hypotension due to loss of vasoconstrictor tone as may
occur during spinal anaesthesia and as an adjunct to accepted remedial procedures.
Posology and method of administration
Method of Administration
For intravenous use.
Direct intravenous injection in grave emergencies: 0.5 - 5 mg (0.05 - 0.5 mL),
followed by an infusion of 15 - 100 mg (1.5 - 10 mL) in 500 mL of infusion
Particular care should be taken to use the correct dose when injecting
Intravenous Infusion: 15 - 100 mg (1.5 - 10.0 mL) in 500 mL Sodium Chloride
Injection or Dextrose 5% Injection, adjusting the rate of infusion to maintain
the blood pressure at the desired level. Higher concentrations of Metaraminol
have been used when appropriate to the circumstances.
Children: Metaraminol should not be used in children under 12 years of age.
Use in the elderly: The dosage may not require modification for elderly
patients; however, geriatric patients may be more sensitive to
sympathomimetic agents, therefore particular caution should be taken in this
Metaraminol Injection should not be used concurrently with cyclopropane or
halothane anaesthesia, unless clinical circumstances demand it.
Metaraminol Injection is contra-indicated in patients who are hypersensitive to the
active ingredient or any of the excipients listed in section 6.1.
There is insufficient data to recommend use in children under 12 years of age.
Special warnings and precautions for use
Caution should be exercised to avoid excessive blood-pressure changes since
response to treatment with metaraminol is very variable and the ensuing control of the
blood pressure may prove difficult.
Rapidly induced hypertensive responses have been reported to cause acute pulmonary
oedema, cardiac arrhythmias and arrest. Metaraminol should be used with caution in
patients with cirrhosis; electrolyte levels should be adequately restored if a diuresis
ensues. A fatal ventricular arrhythmia was reported in a patient with Laennec’s
cirrhosis while receiving metaraminol tartrate. In several instances ventricular
extrasystoles that appeared during infusion of metaraminol promptly subsided when
the rate of flow was reduced.
With the prolonged action of metaraminol, a cumulative effect is possible. An
excessive vasopressor response may cause a prolonged elevation of blood pressure,
even after discontinuation of therapy. Metaraminol should be used with caution in
cases of heart disease, hypertension, thyroid disease or diabetes mellitus because of
the vasoconstrictor action.
Sympathomimetic amines may provoke a relapse in patients with a history of malaria.
When vasopressor amines are used for long periods, the resulting vasoconstriction
may prevent adequate expansion of circulating volume and may cause perpetuation of
the shock state. There is evidence that plasma volume may be reduced in all types of
shock, and that the measurement of central venous pressure is useful in assessing the
adequacy of the circulating blood volume. Blood, or plasma-volume expanders,
should therefore be employed when the principal reason for hypotension of shock is
decreased circulating volume.
In choosing the site for injection, it is important to avoid those areas generally
recognised as being unsuitable for the use of any pressor agent and to discontinue the
infusion immediately if infiltration or thrombosis occurs. Although the urgent nature
of the patient’s condition may force the choice of an unsuitable injection site, the
preferred areas of injection should be used when possible. The larger veins of the
antecubital fossa or thigh are preferred to the veins in the ankle or dorsum of the
hand, particularly in patients with peripheral vascular disease, diabetes mellitus,
Buerger’s disease or conditions with coexistent hypercoagulability.
The preservative sodium metabisulfite in Metaraminol may cause hypersensitivity. In
particular it is associated with circulatory or respiratory collapse, and depression of
the CNS in certain susceptible individuals, particularly in those with asthma.
Accidental spillage of Metaraminol Injection on the skin can cause dermatitic
reactions linked to the presence of the agent’s preservatives.
Interaction with other medicinal products and other forms of interaction
Metaraminol should be used with caution in patients receiving digitalis, since the
combination of digitalis and sympathomimetic amines is capable of causing ectopic
Monoamine oxidase inhibitors have been reported to potentiate the action of
sympathomimetic amines. The pressor effect of metaraminol is decreased but not
reversed by alpha-adrenergic blocking agents.
Fertility, pregnancy and lactation
There are no well-controlled studies in pregnant women. Metaraminol should be used
during pregnancy only if the potential benefit to the mother justifies the potential risk
to the foetus.
It is not known whether metaraminol is secreted in human milk. Because many drugs
are secreted in human milk, caution should be exercised if metaraminol is given to a
There are no fertility data available.
Effects on ability to drive and use machines
The frequency of adverse events with metaraminol has not been firmly
established. Excessive therapeutic effect leading to hypertension, quickly
reversible by reducing the rate of infusion, and headaches are very common.
Adverse reactions listed below are classified according to frequency and
system organ class (SOC). The frequencies of adverse reactions are ranked
according to the following convention: 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).
System Organ Class
Nervous system disorders
Very common: Headache
Not known: Palpitations; sinus tachycardia;
bradycardia; ventricular tachycardia; other
cardiac arrhythmias (especially in patients with
myocardial infarction); fatal ventricular
arrhythmia reported in Laennec’s cirrhosis.
Very Common: Hypertension
Not known: Peripheral ischaemia;
Skin and Subcutaneous
Rare: Abscess formation; tissue necrosis;
Not known: Nausea.
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:
Metaraminol acts rapidly. The major therapeutic effects are complete within an hour
of parenteral administration. Overdosage may result in severe hypertension
accompanied by headache, constricting sensation in the chest, nausea, vomiting,
euphoria, diaphoresis, pulmonary oedema, tachycardia, bradycardia, sinus
arrhythmia, atrial or ventricular arrhythmias, myocardial infarction, cardiac arrest or
If the drug has been ingested, induce emesis or perform gastric lavage. If metaraminol
has been administered by subcutaneous or intramuscular injection, local ice packs
may be applied to delay absorption. Intravenous infusion should be stopped
immediately, but reinstated if hypotension occurs.
If needed, alpha-adrenergic blocking agents may also be useful for reducing
hypertension and may have a beneficial effect on cardiac arrhythmia, if present.
Parenteral diazepam may be given for convulsions.
Pharmacotherapeutic group: Adrenergic and dopaminergic agent. ATC code:
Metaraminol is a sympathomimetic agent with direct and indirect effects on
adrenergic receptors. It has both alpha and beta-adrenergic activity, the former being
Metaraminol increases the force of myocardial contractions as well as having a
peripheral vasoconstrictor action. It increases both systolic and diastolic blood
The vasoconstrictor action of metaraminol is not affected by depletion of the tissue
stores of noradrenaline. Metaraminol is highly effective in displacing and replacing
noradrenaline from the stores in adrenergic neurones and competitively inhibits
noradrenaline uptake. The metaraminol that is taken up by the adrenergic neurones
then acts as a false transmitter.
The overall effects of metaraminol are similar to those of noradrenaline but it is much
less potent and has a more prolonged action. It can cause pulmonary vasoconstriction,
and pulmonary blood pressure is elevated when cardiac output is reduced.
The pressor effect of a single dose of metaraminol lasts from about 20 minutes up to
one hour. Its onset is around one or two minutes after direct intravenous injection.
The vasopressor effects taper off when therapy is stopped.
Preclinical safety data
No relevant information.
List of excipients
Sodium metabisulfite (E223)
Water for injections
Metaraminol must not be mixed with the following medicinal products due to
their additive incompatibilities:
Stable between 2-8ºC for 24-48 hours in an intravenous infusion of Sodium Chloride
0.9% Solution or Glucose 5% Solution.
Special precautions for storage
Do not store above 25ºC.
After dilution, chemical and physical in-use stability has been demonstrated for 48
hours when the diluted product is stored between 2 to 8°C.
From a microbiological point of view, the product should be used immediately. If not
used immediately, in-use storage times and conditions are the responsibility of the
user and would normally not be longer than 48 hours at 2 to 8°C unless opening has
taken place in controlled and validated aseptic conditions.
Nature and contents of container
Glass ampoule containing 1mL of solution for injection or infusion.
Pack size of 10 ampoules in an outer carton.
Special precautions for disposal
Metaraminol Injection maybe diluted with Sodium Chloride 0.9% Injection or
Dextrose 5% Injection. Refer to Section 4.2 Posology and method of administration
for further details.
The product is compatible with:
PVC infusion bags
Any unused product or waste material should be disposed of in accordance with local
MARKETING AUTHORISATION HOLDER
Torbay and South Devon NHS Foundation Trust
Devon TQ4 7FG
MARKETING AUTHORISATION NUMBER(S)
DATE OF FIRST AUTHORISATION/RENEWAL OF THE
DATE OF REVISION OF THE TEXT
Source: Medicines and Healthcare Products Regulatory Agency
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