Summary of Product Characteristics (SmPC) - Phenylephrine 10 mg/ml injection
1 NAME OF THE MEDICINAL PRODUCT
Phenylephrine 10 mg/ml Injection
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each 1 ml ampoule contains 10 mg of the active ingredient phenylephrine hydrochloride.
For the full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
A clear, colourless or slightly brown liquid, free from extraneous visible particles.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Phenylephrine Injection is indicated in adults and children for the treatment of hypotensive states e.g. circulatory failure, during spinal anaesthesia or drug induced hypotension.
4.2 Posology and method of administration
Posology
Adults
Phenylephrine Injection may be administered subcutaneously or intramuscularly in a dosage of 2 to 5 mg with further doses of 1 to 10 mg if necessary according to response, or in a dose of 100 to 500 micrograms by slow intravenous injection as a 0.1% solution, repeated as necessary after at least 15 minutes.
Alternatively, 10 mg in 500 ml of glucose 5% injection or sodium chloride 0.9% injection may be infused intravenously, initially at a rate of up to 180 micrograms per minute, reduced according to response to 30-60 micrograms per minute.
Elderly
There is no need for dosage reduction in the elderly.
Paediatric population
100 mcg/kg body weight subcutaneously or intramuscularly.
Method of administration
For subcutaneous, intramuscular, slow intravenous injection or intravenous infusion.
4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
Patients taking monoamine oxidase inhibitors, or within 14 days of ceasing such treatment.
Severe hypertension and hyperthyroidism.
Avoid in patients with prostatic enlargement.
4.4 Special warnings and precautions for use
Great care should be exercised in administering Phenylephrine Injection to patients with pre-existing cardiovascular disease such as ischaemic heart disease, arrhythmias, occlusive vascular disease including arteriosclerosis, hypertension or aneurysms. Anginal pain may be precipitated in patients with angina pectoris.
Care is also required when given to patients with diabetes mellitus.
Phenylephrine is not recommended in subjects with a shallow anterior chamber or a history of acute narrow angle glaucoma. Use of Phenylephrine 10 mg/ml Injection in patients with shallow anterior chamber, a history of acute narrow angle glaucoma and/or insufficient pupil dilation can increase the risk of both iridocele and floppy iris syndrome.
Keep all medicines out of the reach of children.
This medicine contains less than 1 mmol sodium (23 mg) per ml, that is to say essentially ‘sodium-free’.
4.5 Interaction with other medicinal products and other forms of interaction
Phenylephrine may interact with cyclopropane and halothane and other halogenated inhalational anaesthetics, to induce ventricular fibrillation. An increased risk of arrhythmias may also occur if phenylephrine injection is given to patients receiving cardiac glycosides, quinidine or tricyclic antidepressants.
Phenylephrine is a hypertensive agent and may consequently reverse the action of many antihypertensive drugs. Interactions of phenylephrine with alpha and beta receptor blocking drugs may be complex.
Drugs which have an effect on α
1 adrenoceptors could potentiate (such as clonidine) or inhibit (such as doxazosin) the vasopressive action of phenylephrine.
Caution should be applied when administering atomoxetine concurrently, as there is potential for synergistic pharmacological effects.
Severe hypertension may occur following the use of phenylephrine and atropine or other antimuscarinics.
The pressor effects of phenylephrine may be slightly reduced by lithium carbonate. The effects of phenylephrine may be potentiated by the use of monoamine oxidase inhibitors or reversible inhibitors of monoamine oxidase.
4.6 Fertility, pregnancy and lactation
Pregnancy
The safety of phenylephrine during pregnancy has not been established. Due to the vasoconstrictive properties of phenylephrine, the product should be used with caution in patients with a history of pre-eclampsia. Administration of phenylephrine in late pregnancy or labour may cause foetal hypoxia and bradycardia.
Breast-feeding
The safety of phenylephrine during lactation has not been established. Excretion of phenylephrine in breast milk appears to be minimal.
Fertility
No data available
4.7 Effects on ability to drive and use machines
No adverse effects known.
4.8 Undesirable effects
A tabulated list of undesirable effects is outlined below:
The undesirable effects are listed according to organ systems and following frequency:
Not known (cannot be estimated from the available data)
| System organ class | Undesirable effects |
| Immune system disorders | Hypersensitivity |
| Metabolism and nutrition disorders | Metabolic disorders |
| Psychiatric disorders | Nervousness, insomnia |
| Nervous system disorders | Headache, cerebral haemorrhage, paraesthesia |
| Eye disorders | Mydriasis, angle-closure glaucoma |
| Cardiac disorders | Pulmonary oedema, bradycardia, tachycardia, arrhythmia, angina pectoris, palpitations, cardiac arrest |
| Vascular disorders | Hypotension, dizziness, syncope, flushing |
| Respiratory, thoracic and mediastinal disorders | Dyspnoea |
| Gastrointestinal disorders | Vomiting, salivary hypersecretion |
| Renal and urinary disorders | Dysuria, urinary retention |
| General disorders and administration site conditions | Extravasation, infusion site necrosis, hyperhidrosis |
| Investigations | Increased blood pressure, abnormal blood glucose |
Phenylephrine is without significant stimulating effects on the central nervous system at usual doses.
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 Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
4.9 Overdose
Symptoms
Symptoms of overdosage include headache, vomiting, hypertension and reflex bradycardia and other cardiac arrhythmias. In severe cases confusion, hallucinations and seizures may occur.
Management
Treatment should consist of symptomatic and supportive measures. The hypertensive effects may be treated with an alpha adrenoreceptor blocking drug, such as phentolamine, 5 to 60 mg i.v. over 10-30 minutes, repeated as necessary.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Pharmacotherapeutic group: adrenergic and dopaminergic agent, ATC code: C01CA
Phenylephrine hydrochloride is a sympathomimetic agent with mainly direct effects on adrenergic receptors. It has predominantly alpha-adrenergic activity and is without significant stimulating effects on the central nervous system at usual doses.
Mechanism of action
After injection it produces peripheral vasoconstriction and increased arterial pressure; it also causes reflex bradycardia.
5.2 Pharmacokinetic properties
When injected subcutaneously or intramuscularly, phenylephrine takes 10 to 15 minutes to act. Subcutaneous and intramuscular injections are effective for up to about one and up to about two hours respectively. Intravenous injections are effective for up to about 20 minutes.
Biotransformation
Phenylephrine is metabolised in the liver by monoamine oxidase.
Elimination
The metabolites, their route and rate of excretion have not been identified.
5.3 Preclinical safety data
Phenylephrine has been used to induce cardiac myocyte hypertrophy in cultures of rat neonatal mycocytes at doses of 100 µM and 10 µM. To the best of our knowledge there have been no human studies associating therapeutic phenylephrine use with the development of cardiac myocyte hypertrophy
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Sodium Hydroxide solution 1N
Hydrochloric Acid 36% 1N
Water for injections
6.2 Incompatibilities
Phenylephrine Injection has been stated to be incompatible with alkalies, ferric salts, phenytoin sodium and oxidising agents.
6.3 Shelf life
2 years.
6.4 Special precautions for storage
Store at 2-25°C. Protect from light
6.5 Nature and contents of container
1 ml neutral glass ampoule with red imprint break ring.
Pack size: 6 x 1ml and 10 x 1ml ampoules
Not all pack sizes may be marketed.
6.6 Special precautions for disposal
No special requirements.
7 MARKETING AUTHORISATION HOLDER
Amdipharm UK Limited
Dashwood House,
69 Old Broad Street,
London, EC2M 1QS,
United Kingdom
8 MARKETING AUTHORISATION NUMBER(S)
PL 20072/0226
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE
AUTHORISATION
Date of first authorisation: 17 November 1999
Date of latest renewal: 18 November 2005
10 DATE OF REVISION OF THE TEXT
03/01/2024