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COLICYM 2 MIU Powder for nebuliser solution – Summary of Product Characteristics (SmPC) for healthcare professionals

Last updated: · Text from the MHRA, as of · About this document

Medicine status: Prescription only (POM) Details

The Summary of Product Characteristics (SmPC) is written for healthcare professionals. Patients will find plain advice in the patient information leaflet: how to take, side effects, other medicines, pregnancy and breast-feeding.

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Summary of Product Characteristics (SmPC) - Colicym 2 MIU powder for nebuliser solution

1 NAME OF THE MEDICINAL PRODUCT

COLICYM 2 MIU Powder for nebuliser solution

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Each vial contains 2 million IU colistimethate sodium.

This medicinal product contains 0.46 mmol (or 10.52 mg) sodium per vial.

For the full list of excipients, see section 6.1.

3 PHARMACEUTICAL FORM

Powder for nebuliser solution.

White to off-white powder.

4 CLINICAL PARTICULARS

4.1 Therapeutic indications

COLICYM by inhalation is indicated for the management of adult and paediatric chronic pulmonary infections due to Pseudomonas aeruginosa in patients with cystic fibrosis (see section 5.1).

Consideration should be given to official guidance on the appropriate use of antibacterial agents.

4.2 Posology and method of administration

It is recommended that colistimethate sodium (CMS) should be administered under the supervision of physicians with appropriate experience in its use.

Posology

The dosage can be adjusted depending on the severity of the condition and clinical response.

Recommended dose range:

Administration via inhalation

Adults, adolescents and children ≥ 2 years

1-2 MIU two to three times per day (max 6 MIU/day)

Children < 2 years

0.5-1 MIU twice daily (max 2 MIU/ day)

Relevant clinical guidance on treatment regimens, including duration of treatment, periodicity and co-administration of other antibacterial agents should be adhered to.

Elderly

Dose adjustment is not considered necessary.

Renal impairment

Dose adjustment is not considered necessary, however caution is advised in patients with renal impairment (see sections 4.4 and 5.2).

Hepatic impairment

Dose adjustment is not considered necessary.

Method of administration

For inhalation use.

Suitable nebulisers are the reusable jet nebulisers including the PARI LC PLUS or the PARI LC SPRINT, which are used with a suitable compressor (PARI JuniorBOY SX and PARI TurboBOY SX accordingly), or the membrane nebuliser namely eFlow rapid.

Both types of compressor are on/off switch and user friendly.

COLICYM 2 MIU is intended for administration by nebulisation using a suitable nebuliser as mentioned above.

Drug delivery characteristics from in vitro studies with the different nebuliser systems are detailed in the table below:

Nebuliser System
ParameterPARI LC SprintPARI LC pluseFlow rapid
Total Drug Delivered from Nebuliser mouthpiece (Million IU)1.2561.3191.207
Drug delivery rate (Million0.1190.1240.183

IU/minute)

Fine Particle Fraction (% <5 μm)65.353.750.0
Droplet Size Distribution.Mass Median Aerodynamic Diameter (MMAD) (μm)3.74.44.8
Geometric Standard Deviation (GSD)2.42.11.8
Measured using COLICYM 2 MIU reconstituted with 4 mL of 0.9% sodium chloride solution

Colistimethate sodium is very soluble in the reconstitution medium. The recommended technique for dissolving the medicinal product is the addition of 4 mL isotonic sodium chloride solution (0.9% w/w) or water for injection, to the vial containing COLICYM 2 MIU by gentle shaking.

Due to potential foaming, vigorous shaking should be avoided. The resulting solution for nebulisation should be clear and carefully transferred into the medication reservoir of the nebuliser.

The solution is for single use only and any remaining solution should be discarded.

The nebuliser must be kept according to the instructions of the corresponding nebuliser during operation.

The patient should sit in an upright position and breathing normally during inhalation. Inhalation should be performed without any interruption to normal breathing.

The nebuliser must be cleaned and disinfected after use as described in the 'instruction of use' of the corresponding nebuliser.

Colistimethate sodium undergoes hydrolysis to the active substance colistin in aqueous solution. For special precautions for disposal and handling of reconstituted solutions, see section 6.6.

If other treatments are being taken, they should be taken in the order recommended by the physician.

Dose conversion

In the EU, the dose of colistimethate sodium (CMS) must be prescribed and administered only as IU. The product label states the number of IU per vial.

Confusion and medication errors have occurred because of the different expressions of dose in terms of potency. The dose is expressed in the US, and other parts of the world, as milligrams of colistin base activity (mg CBA).

The following conversion table is prepared for information and the values must be considered nominal and approximate only.

CMS conversion table
Potency≈ mass of CMS (mg) *
IU≈ mg CBA
12 5000.41
150 000512
1 000 0003480
4 500 000150360
9 000 000300720

* Nominal potency of the drug substance = 12,500 IU/mg

4.3 Contraindications

Hypersensitivity to colistimethate sodium, colistin or to polymyxin B.

4.4 Special warnings and precautions for use

Bronchospasm

Nebulisation of colistimethate sodium may induce coughing or bronchospasm. It is advisable to administer the first dose under medical supervision. Pre-dosing with a bronchodilator is recommended and should be routine, especially if this is part of the patient’s current therapeutic regimen. FEV1 should be evaluated pre and post dosing. If there is evidence of colistimethate sodium induced bronchial hyperreactivity in a patient not receiving pre-treatment bronchodilators the test should be repeated on a separate occasion using a bronchodilator. Evidence of bronchial hyperreactivity in the presence of a bronchodilator may indicate an allergic response and Promixin should be discontinued. Bronchospasm that occurs should be treated as medically indicated. Bronchial hyperreactivity in response to colistimethate sodium may develop with continued use over time and it is recommended that pre and post treatment FEV1s are evaluated at regular clinic visits.

Renal impairment

Colistimethate sodium is renally excreted and is nephrotoxic if high serum concentrations are

achieved. Whilst this is unlikely during inhalation therapy, serum concentration estimations are

recommended especially in patients with renal impairment.

Nephrotoxicity/Neurotoxicity

Nephrotoxicity or neurotoxicity may occur if the recommended parenteral dose is exceeded. The

risk is reduced due to the low bioavailability during inhalation, but ColiFin should be used with

caution in patients with renal impairment. Appearance of neurotoxic reactions as well as the renal

function should be monitored.

In premature and newborn infants special care should be employed as renal function is only

insufficiently developed in this population.

Colistimethate sodium is known to reduce the presynaptic release of acetyl-choline at the neuro-muscular junction and should be used in patients with myasthenia gravis with the greatest caution and only if clearly needed.

Porphyria

Use with extreme caution in patients with porphyria.

Microbial Resistance

Colistimethate sodium acquired resistance in mucoid Pseudomonas aeruginosa during clinical use

has been reported. Susceptibility testing should be performed on patients who are treated on a

long term basis, at regular clinic visits, and whenever a patient experiences an exacerbation (see Section 5.1).

4.5 Interaction with other medicinal products and other forms of interaction

Caution should be taken with concomitant use with other formulations of colistimethate sodium as there is little experience and there is a possibility of summative toxicity.

No in vivo interaction studies have been performed. The mechanism of conversion of colistimethate sodium to the active substance, colistin, is not characterised. The mechanism of colistin clearance, including renal handling, is equally unknown. Colistimethate sodium or colistin did not induce the activity of any P 450 (CYP) enzyme tested (CYP1A2, 2B6, 2C8, 2C9, 2C19 and 3A4/5) in in vitro studies in human hepatocytes.

The potential for drug-drug interactions should be borne in mind when colistimethate is co-administered with drugs known to inhibit or induce drug metabolising enzymes or drugs known to be substrates for renal carrier mechanisms.

Due to the effects of colistin on the release of acetylcholine, non-depolarising muscle relaxants should be used with caution in patients receiving colistimethate sodium as their effects could be prolonged (see section 4.4).

Co-treatment with colistimethate sodium and macrolides such as azithromycin and clarithromycin, or fluoroquinolones such as norfloxacin and ciprofloxacin should be undertaken with caution in patients with myasthenia gravis (see section 4.4).

Concomitant use of colistimethate sodium with other medicinal products of neurotoxic and/or nephrotoxic potential should be avoided. These include the aminoglycoside antibiotics such as gentamicin, amikacin, netilmicin and tobramycin. There may be an increased risk of nephrotoxicity if given concomitantly with cephalosporin antibiotics.

4.6 Fertility, pregnancy and lactation

Pregnancy

There are no adequate data from the use of colistimethate sodium in pregnant women. Single dose studies in human pregnancy show that colistimethate sodium crosses the placental barrier and there may be a risk of foetal toxicity if repeated doses are given to pregnant patients. Animal studies are insufficient with respect to the effect of colistimethate sodium on reproduction and development (see section 5.3, Preclinical safety data). Colistimethate sodium should be used in pregnancy only if the benefit to the mother outweighs the potential risk to the foetus.

Breastfeeding

Colistimethate sodium is secreted in breast milk. Colistimethate sodium should be administered to breastfeeding women only when clearly needed.

4.7 Effects on ability to drive and use machines

During parenteral treatment with colistimethate sodium neurotoxicity may occur with the possibility of dizziness, confusion or visual disturbance. Patients should be warned not to drive or operate machinery if these effects occur.

4.8 Undesirable effects

The commonest undesirable effects following nebulisation of colistimethate sodium are coughing and bronchospasm (indicated by chest tightness which may be detected by a decrease in FEV1) in approximately 10% of patients. (See also Section 4.4) Adverse reactions are tabulated below by system organ class and frequency. 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) and very rare (<1/10,000), not known (cannot be estimated from the available data).

Body SystemFrequencyReported adverse reaction
Immune system disordersNot knownHypersensitivity reactions such as skin rash

Respiratory, thoracic and mediastinal

disorders

Very common

Cough, chest tightness, bronchoconstriction or bronchospasm,

Pharyngolaryngeal discomfort, dyspnoea, forced expiratory volume decreased

General disorders and administration

site conditions

Not knownSore throat and sore mouth
Psychiatric disordersNot knownConfusional state Psychotic disorder
Nervous system disordersNot known

Dizziness

Paraesthesia

Dysarthria

Autonomic nervous system imbalance

Visual disturbance

Vertigo

Renal and urinary disordersNot knownRenal failure

Sore throat or mouth has been reported and may be due to Candida albicans infection or hypersensitivity. Skin rash may also indicate hypersensitivity, if this occurs treatment should be withdrawn.

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 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

Overdose can result in neuromuscular blockade that can lead to muscular weakness, apnoea and possible respiratory arrest. Overdose can also cause acute renal failure characterised by decreased urine output and increased serum concentrations of BUN and creatinine.

There is no specific antidote, manage by supportive treatment. Measures to increase the rate of elimination of colistin e.g. mannitol diuresis, prolonged haemodialysis or peritoneal dialysis may be tried, but effectiveness is unknown.

5 PHARMACOLOGICAL PROPERTIES

5.1 Pharmacodynamic properties

Pharmacotherapeutic group: antibacterials for systemic use, other antibacterials, polymyxins

ATC Code: J01XB01

Mechanism of action

Colistimethate sodium is the prodrug of colistin. Colistin is a cyclic polypeptide antibacterial agent belonging to the polymyxin group. Polymyxins work by damaging the cell membrane and the resulting physiological effects are lethal to the bacterium. Polymyxins are active against aerobic Gram-negative bacteria that have a hydrophobic outer membrane.

Resistance

Resistant bacteria are characterised by modification of the phosphate groups of lipopolysaccharide, which become substituted with ethanolamine or aminoarabinose. Naturally resistant Gram-negative bacteria, such as Proteus mirabilis and Burkholderia cepacia, show complete substitution of their lipid phosphate by ethanolamine or aminoarabinose.

Cross resistance between colistin (polymyxin E) and polymyxin B is expected. Since the mechanism of action of the polymyxins is different from that of other antibacterial agents, resistance to colistin and polymyxin by the above mechanism alone would not be expected to result in resistance to other drug classes.

PK/PD relationship

Polymyxins have been reported to have a concentration-dependent bactericidal effect on susceptible bacteria. fAUC/ MIC is considered to be correlated with clinical efficacy.

Susceptibility

The prevalence of acquired resistance may vary geographically and with time for selected species and local information on resistance is desirable, particularly when treating severe infections. As necessary, expert advice should be sought when the local prevalence of resistance is such that the utility of the agent in at least some types of infections is questionable.

5.2 Pharmacokinetic properties

Absorption

Absorption from the gastrointestinal tract does not occur to any appreciable extent in the normal individual.

When given by nebulisation, variable absorption has been reported that may depend on the aerosol particle size, nebulizer system and lung status. A study in healthy volunteers, who inhaled colistimethate sodium, demonstrated the Cmax of polymyxin E1 (the active moiety) varied between 40.0 and 69.9 ng/mL and the AUC varied between 350 and 668 ng/mL/h depending on the nebuliser and the fill volume and concentration, which varied the dose from 0.3 million IU to 2 million IU. The half-life was approximately 5.2 hours. The absolute bioavailability was calculated to vary between 5% and 18% depending on the nebuliser. The AUC following an intravenous dose of 0.5 million IU was 3,352 ng/mL/h and the Cmax was 1,232 ng/mL.

Distribution

After intravenous administration, the volume of distribution of colistin in healthy subjects is low and corresponds approximately to extracellular fluid (ECF). The volume of distribution is relevantly enlarged in critically ill subjects. Protein binding is moderate and decreases at higher concentrations. In the absence of meningeal inflammation, penetration into the cerebrospinal fluid (CSF) is minimal, but increases in the presence of meningeal inflammation.

Both CMS and colistin display linear PK in the clinically relevant dose range.

Elimination

There is no information on the elimination of colistimethate sodium following nebulisation.

After intravenous administration, it is estimated that approximately 30% of colistimethate sodium is converted to colistin in healthy subjects, its clearance is dependent on creatinine clearance and as renal function decreases, a greater portion of CMS is converted to colistin. In patients with very poor renal function (creatinine clearance <30 mL/min), the extent of conversion could be as high as 60 to 70%. CMS is eliminated predominantly by the kidneys via glomerular filtration. In healthy subjects, 60% to 70% of CMS is excreted unchanged in the urine within 24 hours. The elimination of the active colistin is incompletely characterised. Colistin undergoes extensive renal tubular reabsorption and may either be cleared non-renally or undergo renal metabolism with the potential for renal accumulation. Colistin clearance is decreased in renal impairment, possibly due to increased conversion of CMS. Half-life of colistin in healthy subjects and those with cystic fibrosis is reported to be around 3h and 4h, respectively, with a total clearance of around 3L/h. In critically ill patients, half-life has been reported to be prolonged to around 9-18h.

5.3 Preclinical safety data

Data on potential genotoxicity are limited and carcinogenicity data for colistimethate sodium are lacking. Colistimethate sodium has been shown to induce chromosomal aberrations in human lymphocytes, in vitro. This effect may be related to a reduction in mitotic index, which was also observed.

Reproductive toxicity studies in rats and mice do not indicate teratogenic properties. However, colistimethate sodium given intramuscularly during organogenesis to rabbits at 4.15 and 9.3 mg/kg resulted in talipes varus in 2.6 and 2.9% of fetuses respectively. These doses are 0.5 and 1.2 times the maximum daily human dose. In addition, increased resorption occurred at 9.3 mg/kg.

There are no other preclinical safety data of relevance to the prescriber which are additional to safety data derived from patient exposure and already included in other sections of the SPC.

6 PHARMACEUTICAL PARTICULARS

6.1 List of excipients

None.

6.2 Incompatibilities

Mixed nebuliser solutions involving colistimethate sodium should be avoided.

6.3 Shelf life

Before opening:

36 months.

Reconstituted solutions:

Hydrolysis of colistimethate is significantly increased when reconstituted below its critical micelle concentration of about 80,000 IU per mL.

Solutions below this concentration should be used immediately.

For solutions for nebulisation, the chemical and physical in-use stability of reconstituted solution in the original vial, with a concentration ≥ 80,000 IU/mL, has been demonstrated for:

  • 2 MIU for 24 hours at 2-8°C when dissolved in 4 mL of Sodium chloride 0.9% or Water for injection.

From a microbiological point of view, unless the method of opening/ reconstitution precludes the risk of microbial contamination, the product should be used immediately.

If not used immediately, in-use storage times and conditions are the responsibility of user.

6.4 Special precautions for storage

This medicinal product does not require any special storage conditions. For storage of solutions following reconstitution refer to section 6.3.

6.5 Nature and contents of container

Clear type I 10R glass vials closed with bromobutyl closures 20 mm and sealed with 20 mm aluminum pull-off or tear-off caps.

Colistimethate sodium are supplied as packs of 1, 10 or 30 vials.

Not all pack sizes may be marketed.

6.6 Special precautions for disposal

For inhalation by nebuliser:

Reconstitute the contents of the vial with either water for injections or with sodium chloride 9 mg/ml (0.9% solution).

Colistimethate sodium is very soluble in the reconstitution medium. The recommended technique for dissolving the medicinal product is the addition of 4 mL isotonic sodium chloride solution for the vial containing COLICYM 2 MIU. During reconstitution swirl gently to avoid frothing.

The output from the nebuliser may be vented to the open air or a filter may be fitted. Nebulisation should take place in a well ventilated room.

Solutions are for single use only and any remaining solution should be discarded.

7 MARKETING AUTHORISATION HOLDER

Noridem Enterprises Limited

Evagorou and Makariou,

Mitsi Building 3,

Office 115, 1065 Nicosia, Cyprus

8 MARKETING AUTHORISATION NUMBER(S)

PL 24598/0090

9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE

AUTHORISATION

04/07/2022

10 DATE OF REVISION OF THE TEXT

05/06/2023

About this document

Source: MHRA - Medicines and Healthcare products Regulatory Agency (products.mhra.gov.uk) · Marketing authorisation: PL 24598/0090

Last revision stated in the text: 5 June 2023 · MHRA data as of 13 October 2026

Found a mistake? Tell us on the contact page.

The information on this site does not replace the advice of a doctor or pharmacist.

Facts about Colicym 2 MIU powder for nebuliser solution

Prescription needed? Yes, prescription-only medicine (POM)
Active substance Colistin
Pharmaceutical form White to off-white powder.
Excipients None.
Is it available? Listed as available (NHS Dictionary of Medicines and Devices – not a record of current supplies)
Shelf life Before opening:
36 months.
Reconstituted solutions:
Hydrolysis of colistimethate is significantly increased when reconstituted below its critical micelle concentration of about 80,000 IU per mL.
Solutions below this concentration should be used immediately.
For solutions for nebulisation, the chemical and physical in-use stability of reconstituted solution in the original vial, with a concentration ≥ 80,000 IU/mL, has been demonstrated for:
2 MIU for 24 hours at 2-8°C when dissolved in 4 mL of Sodium chloride 0.9% or Water for injection.
From a microbiological point of view, unless the method of opening/ reconstitution precludes the risk of microbial contamination, the product should be used immediately.
If not used immediately, in-use storage times and conditions are the responsibility of user.
Storage This medicinal product does not require any special storage conditions. For storage of solutions following reconstitution refer to section 6.3.
Drug group (ATC) Antibacterials for systemic use, other antibacterials, polymyxins
  1. J Antiinfectives for systemic use
    1. J01 Antibacterials for systemic use
      1. J01X Other antibacterials
        1. J01XB Polymyxins
          1. J01XB01 colistin
Marketing authorisation PL 24598/0090 (first authorised 4 July 2022)
Marketing authorisation holder Noridem Enterprises Limited

Sources: the MHRA product information (products.mhra.gov.uk) and the NHS Dictionary of Medicines and Devices (dm+d), release 10.2.0 of 19 October 2026, NHS Business Services Authority. Contains public sector information licensed under the Open Government Licence v3.0.