Co-Trimoxazole 16mg/80mg per ml Solution for Infusion

Patient Leaflet Updated 18-Sep-2026 | Wockhardt UK Ltd

Co-trimoxazole 16mg/80mg per ml Solution for Infusion

Package leaflet: Information for the patient

Co-trimoxazole 16mg/80mg per ml Solution for Infusion

trimethoprim and sulfamethoxazole

Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.
  • Keep this leaflet. You may need to read it again
  • If you have any further questions, ask your doctor or pharmacist
  • This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours
  • If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

What is in this leaflet

1. What Co-trimoxazole is and what it is used for
2. What you need to know before you are given Co-trimoxazole
3. How Co-trimoxazole is given
4. Possible side effects
5. How to store Co-trimoxazole
6. Contents of the pack and other information

1. What Co-trimoxazole is and what it is used for

Co-trimoxazole 16mg/80mg per ml Solution for Infusion (called ‘Co-trimoxazole’ in this leaflet) is a combination of two different antibiotics called sulfamethoxazole and trimethoprim, which is used to treat infections caused by certain bacteria. Like all antibiotics, Co-trimoxazole only works against some types of bacteria. This means that it is only suitable for treating some types of infections.

Co-trimoxazole can be used to treat or prevent:

  • lung infections (pneumonia or PJP) caused by a bacteria called Pneumocystis jirovecii
  • infections caused by a bacteria called Toxoplasma (toxoplasmosis).

Co-trimoxazole can be used to treat:

  • urinary bladder or urinary tract infections (water infections)
  • an infection called nocardiosis which can affect the lungs, skin and brain.

Co-trimoxazole will usually only be given to you if you are unable to take medicines by mouth.

Consideration should be given to the official guidance in the appropriate use of antibacterial agents. Co-trimoxazole is indicated in children (≥6 weeks) and adults.

2. What you need to know before you are given Co-trimoxazole
Co-trimoxazole is contraindicated in the following situations:
  • if you are allergic to sulfamethoxazole, trimethoprim or Co-trimoxazole or any of the other ingredients of this medicine (listed in section 6). If you are allergic to sulphonamide medicines. Examples include sulphonylureas (such as gliclazide and glibenclamide) or thiazide diuretics (such as bendroflumethiazide–a water tablet)
  • if you have severe liver or severe kidney problems
  • if you have ever had a problem with your blood causing bruises or bleeding (thrombocytopenia)
  • if you have been told that you have a rare blood problem called porphyria, which can affect your skin or nervous system
  • Co-trimoxazole should not be given to infants during the first 6 weeks of life
  • if you are pregnant (first 3 months) or might be pregnant.

If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking Co-trimoxazole.

Warnings and precautions

Talk to your doctor or pharmacist before being given Co-trimoxazole:

  • if you have ever developed a severe skin rash or skin peeling, blistering and/or mouth sores after taking Co-trimoxazole
  • if you have severe allergies or asthma
  • potentially life-threatening skin rashes (Stevens-Johnson syndrome, toxic epidermal necrolysis and drug reaction with eosinophilia and systemic symptoms) have been reported with the use of Co-trimoxazole appearing initially as reddish target-like spots or circular patches often with central blisters on the trunk
  • at the start of treatment, the occurrence of a generalised skin redness with pustules, accompanied by fever, should raise the suspicion of a serious reaction called generalised acute exanthematous pustulosis (AGEP) (see section 4)
  • additional signs to look for include ulcers in the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes)
  • these potentially life-threatening skin rashes are often accompanied by flu-like symptoms. The rash may progress to widespread blistering or peeling of the skin
  • the highest risk for occurrence of serious skin reactions is within the first weeks of treatment
  • if you have developed Stevens-Johnson syndrome, toxic epidermal necrolysis or drug reaction with eosinophilia and systemic symptoms with the use of Co-trimoxazole you must not be re-started on Co-trimoxazole at any time
  • if you develop a rash or these skin symptoms, seek immediate advice from a doctor and tell him that you are taking this medicine (see section 4)
  • haemophagocytic lymphohistiocytosis
    There have been very rare reports about excessive immune reactions due to a dysregulated activation of white blood cells resulting in inflammations (haemophagocytic lymphohistiocytosis), which can be life-threatening if not diagnosed and treated early. If you experience multiple symptoms such as fever, swollen glands, feeling weak, lightheaded, shortness of breath, bruising, or skin rash simultaneously or with a slight delay, contact your doctor immediately
  • if you develop an unexpected worsening of cough and shortness of breath, inform your doctor immediately
  • if you have been told that you are at risk for a rare blood disorder called porphyria
  • if you don’t have enough folic acid (a vitamin) in your body - which can make your skin pale and make you feel tired, weak and breathless. This is known as anaemia
  • if you have a disease called glucose-6-phosphate dehydrogenase deficiency, which can cause jaundice or spontaneous destruction of red blood cells
  • if you have a problem with your metabolism called phenylketonuria and are not on a special diet to help your condition
  • if you are elderly
  • if you are underweight or malnourished
  • if you have been told by your doctor that you have a lot of potassium in your blood.

Concomitant administration of Co-trimoxazole with certain medicines, potassium supplements and food rich in potassium may lead to severe hyperkalaemia (increased potassium blood level). The symptoms of severe hyperkalaemia might include muscle cramps, irregular heart rhythm, diarrhoea, nausea, dizziness or headache

  • if you have a kidney disease
  • if you have severe allergy or bronchial asthma
  • if you have a severe blood disorder, such as a low number of red blood cells (anaemia), a low number of white blood cells (leucopenia) or a low number of platelets, which may cause bleeding and bruising (thrombocytopenia).

Other medicines and Co-trimoxazole

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

This is because Co-trimoxazole can affect the way some medicines work. Also some other medicines can affect the way Co-trimoxazole works.

In particular, tell your doctor or pharmacist if you are taking any of the following medicines:

  • diuretics (water tablets), which help increase the amount of urine you produce
  • pyrimethamine, used to treat and prevent malaria, and to treat diarrhoea
  • ciclosporin, used after organ transplant surgeries
  • blood thinners such as warfarin
  • phenytoin, used to treat epilepsy (fits)
  • medicines used to treat diabetes, such as glibenclamide, glipizide or tolbutamide (sulphonylureas) and repaglinide
  • medicines to treat problems with the way your heart beats such as digoxin or procainamide
  • amantadine, used to treat Parkinson’s disease, multiple sclerosis, flu or shingles
  • medicines to treat HIV (Human Immunodeficiency Virus), called zidovudine or lamivudine
  • medicines that can increase the amount of potassium in your blood, such as diuretics (water tablets, which help increase the amount of urine you produce, such as spironolactone), steroids (like prednisolone) and digoxin digoxin or ACE inhibitors (may be used to treat high blood pressure or some heart problems)
  • azathioprine, may be used in patients following organ transplant or to treat immune system disorders or inflammatory bowel disease
  • methotrexate, a medicine used to treat certain cancers or certain diseases affecting your immune system
  • rifampicin, an antibiotic
  • folinic acid
  • contraceptive medicines
  • methenamine hippurate. This medicine may interact with co-trimoxazole and contribute to the formation of crystals in the urine (crystalluria), potentially leading to kidney problems.

Pregnancy and breast-feeding

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

This medicine should not be taken during first three months of pregnancy. Treatment with trimethoprim in the first three months of pregnancy may increase the risk of miscarriage. Children born to mothers treated with trimethoprim during the first trimester of pregnancy may have an increased risk of birth defects, in particular neural tube defects (where the spine and spinal cord do not form properly) and defects affecting the heart.

See following section for more information about ethanol content in the formulation.

Driving and using machines

Effects on the ability to drive and operate machinery in patients taking this medicine have not been studied.

Co-trimoxazole contains
  • sodium metabisulphite. This can cause allergic type reactions including skin rash; swelling of eyelids, face or lips or difficulty in breathing. This is rare, but you may be more at risk if you suffer from allergies or asthma
  • 11.14 vol% ethanol (alcohol). There can be up to 557mg per dose. This is equivalent to 13.22ml of beer, or 5.5ml of wine. It may be harmful if you are alcoholic. The ethanol content should also be taken in to account if you are pregnant or breast-feeding, a child or if you have liver problems or epilepsy
  • 1.7 mmoles (or 39.41mg) of sodium. To be taken into consideration by patients on a sodium controlled diet
  • 2340mg of propylene glycol in each 5ml. If your child is less than 5 years old, talk to your doctor or pharmacist before giving them this medicine, in particular if they use other medicines that contain propylene glycol or alcohol. If you are pregnant or breast-feeding, do not take this medicine unless recommended by your doctor. If you suffer from a liver or kidney disease, do not take this medicine unless recommended by your doctor. Your doctor may carry out extra checks while you are taking this medicine.

3. How Co-trimoxazole is given

You will never be expected to give yourself this medicine. It will always be given to you by a person who is trained to do so.

Co-trimoxazole will be given to you as a continuous infusion into your vein. This is where the drug is slowly given to you over a period of time.

Before the medicine is given to you it will be diluted.

Dilution should be carried out immediately before use.

The dose you will be given, and the frequency of the dose will depend on:

  • the type of infection you have
  • your weight
  • your age.

Posology

Standard dosage recommendations for acute infections

Treatment should be continued until you have been free from symptoms for 2 days. It is likely you will require treatment for at least 5 days. In case of severe infections, dosage may be increased by 50%.

Adults and children over 12 years:

STANDARD DOSAGE: 2 ampoules (10ml) every 12 hours

Children aged 12 years and under:

The standard dosage for children is equivalent to approximately 6mg trimethoprim and 30mg sulfamethoxazole per kg body weight per day, given in two equally divided doses.

Age Dosage

6 weeks to 5 months 1.25 ml every 12 hours

6 months to 5 years 2.5 ml every 12 hours

6 to 12 years 5.0 ml every 12 hours

If you have kidney problems your doctor may
  • prescribe a lower dose of Co-trimoxazole
  • take blood to test whether the medicine is working properly.

If you are given more Co-trimoxazole than you should

If you think you have been given more Co-trimoxazole, talk to your doctor or nurse straight away. If you have been given too much Co-trimoxazole you may:

  • feel or be sick
  • feel dizzy or confused.

4. Possible side effects

Like all medicines, Co-trimoxazole can cause side effects, although not everybody gets them. You may experience the following side effects with this medicine.

Stop taking Co-trimoxazole and tell your doctor immediately if you notice any of the following symptoms:

  • if you have an allergic reaction. Chances of an allergic reaction is very rare (fewer than 1 in 10,000 people are affected), signs of an allergic reaction include:
    • difficulty in breathing
    • fainting
    • swelling of face
    • swelling of mouth, tongue or throat which may be red and painful and/or cause difficulty in swallowing
    • chest pain
    • red patches on the skin.
  • reddish patches on the trunk, often with central blisters, skin peeling, ulcers of mouth, throat, nose, genitals and eyes. These serious skin rashes can be preceded by fever and flu like symptoms (Stevens-Johnson syndrome (SJS)/ toxic epidermal necrolysis (TEN)
  • widespread rash, high body temperature and enlarged lymph nodes (DRESS syndrome or drug hypersensitivity syndrome).

Call the emergency department immediately if you experience multiple symptoms such as fever, very low blood pressure or increased heart rate after taking this drug as it may be a sign of shock.

Very Common (more than 1 in 10 people)

  • high levels of potassium in your blood, which can cause abnormal heart beats (palpitations).

Common (less than 1 in 10 people)

  • a fungal infection called thrush or candidiasis which can affect your mouth or vagina
  • headache
  • feeling sick (nausea)
  • diarrhoea
  • skin rashes.

Uncommon (less than 1 in 100)

  • being sick (vomiting).

Very Rare (less than 1 in 10,000 people)

  • fever (high temperature) or frequent infections
  • sudden wheeziness or difficulty breathing
  • very rare cases of redness generalising to the whole body (generalised acute exanthematous pustulosis (AGEP)) (see section 2).
  • mouth ulcers, cold sores and ulcers or soreness of your tongue
  • skin lumps or hives (raised, red or white, itchy patches of skin)
  • blisters on your skin or inside your mouth, nose, vagina or bottom
  • inflammation of the eye which causes pain and redness
  • the appearance of a rash or sunburn when you have been outside (even on a cloudy day)
  • low levels of sodium in your blood
  • changes in blood tests
  • feeling weak, tired or listless, pale skin (anaemia)
  • heart problems
  • jaundice (the skin and the whites of your eyes turn yellow). This can occur at the same time as unexpected bleeding or bruising
  • pains in your stomach, which can occur with blood in your faeces (stools)
  • pains in your chest, muscles or joints and muscle weakness
  • arthritis
  • problems with your urine. Difficulty passing urine. Passing more or less urine than usual. Blood or cloudiness in your urine
  • kidney problems
  • sudden headache or stiffness of your neck, accompanied by fever (high temperature).
  • problems controlling your movements
  • fits (convulsions or seizures)
  • feeling unsteady or giddy
  • ringing or other unusual sounds in your ears
  • tingling or numbness in your hands and feet
  • seeing strange or unusual sights (hallucinations)
  • depression
  • muscle pain and/or muscle weakness in HIV patients
  • loss of appetite.

Unknown frequency (cannot be estimated from the available data)

  • psychotic disorder (a mental state in which you may lose touch with reality)
  • plum-coloured, raised painful sores on the limbs and sometimes on the face and neck with a fever (Sweets syndrome).

If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or nurse.

Reporting of side effects

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly 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. By reporting side effects, you can help provide more information on the safety of this medicine.

5. How to store Co-trimoxazole

Keep this medicine out of the sight and reach of children.

This medicinal product does not require any special temperature storage conditions. Keep the ampoules in the outer carton in order to protect from light

Do not have this medicine after the expiry date shown on the carton and label.

6. Contents of the pack and other information What Co-trimoxazole contains

Co-trimoxazole is made up of two different medicines called sulfamethoxazole and trimethoprim.

The other ingredients of Co-trimoxazole are: propylene glycol (E1520), trometamol, sodium hydroxide (E524), sodium metabisulphite (E223), ethanol, hydrochloric acid and water for injections.

What Co-trimoxazole looks like and contents of the pack

Co-trimoxazole is a colourless or slightly yellow solution available in 5ml type I clear glass ampoules.

Each 5ml ampoule contains 400mg sulfamethoxazole and 80mg trimethoprim. The ampoules are supplied in packs of 10.

Marketing Authorisation Holder:
Wockhardt UK Ltd
Ash Road North
Wrexham
LL13 9UF
UK

Manufacturer:
CP Pharmaceuticals Ltd
Ash Road North
Wrexham
LL13 9UF
UK

Other formats

To listen to or request a copy of this leaflet in Braille, large print or audio please call, free of charge: 0800 198 5000 (UK Only). Please be ready to give the following information:

Product name Reference number

Co-trimoxazole 16mg/80mg per ml Solution for Infusion 29831/0792

This is a service provided by the Royal National Institute of Blind People

This leaflet was last revised in 09/2026.

108983/3

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