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Antibiotics For Children: Storage And Expiry Dates


Appropriate storage of medicines, such as liquid antibiotics for children, is essential to ensure the medication’s effectiveness and stability. In this post, I will be portraying storage instructions and expiry dates of liquid antibiotics for children (solutions/syrups) available in the UK, commonly used to treat various infections in children or adults with swallowing difficulties. Store instruction and expiry dates can be always found on the dispensing label, product information leaflet, and on the product label which covers the antibiotic bottle.


Do All Antibiotics For Children Need To Be Kept In The Fridge?

Most liquid antibiotics available in the UK come in the form of powder/granules for reconstitution. The powder is usually mixed by a member of a pharmacy team with the water at the point of dispensing unless the GP or patient indicates otherwise. When mixed with water, some liquid antibiotics must be kept in the fridge, whereas others can be kept at room temperature. For specific storage recommendations please read on.

A small number of antibiotics, such as Trimethoprim suspension, come as ready-made solutions, which are kept at room temperature.

At What Temperature Should Antibiotics For Children Be Stored?

Antibiotics that need to be refrigerated should be kept at 2°C-8°C.

Do All Antibiotics For Children Have Expiry Dates?

Once made up, liquid antibiotics for children have an expiry date, usually 7 or 14 days, from the reconstitution (mixing of the powder/granules with water), shorter expiry times of 5 days are also possible. Patients are normally given a part supply of liquid antibiotics which has a shelf life of 7 days when the prescriber issues a 10 or 14 days treatment course. This is to ensure that:

  • a correct reconstitution takes place when the second bottle of antibiotic is needed and
  • the second bottle is reconstituted after the first one is used up, so both do not expire at the same time

Patients may ask a pharmacy team to supply antibiotics in their dry form. Mixing the antibiotic with water is straightforward, however, the correct amount of water needs to be used for reconstitution. Quantity of water (in millilitres) is always given on the product label,  present on the bottle. The amount of water that needs to be added to the dry powder varies between different forms of antibiotics for children. Children may be given an incorrect amount of an antibiotic if the wrong amount of water is used to mix it with the powder.

What Should You Do When An Antibiotic Is Left Out Of The Fridge Accidentally?

What should you do when an antibiotic is out of the fridge accidentally

None of the 'official' documents advise on what to do when antibiotics are accidentally left out of the fridge for a prolonged time. It would be unwise to make any assumptions supporting the use of antibiotics left accidentally outside the refrigerator. 

since stability and hence the effectiveness of antibiotics may be compromised. Patients who left liquid antibiotics outside the fridge should contact their GP in the first instance to get a replacement script for another bottle of medicine. Patients may try to call the pharmacy instead; however, the request for antibiotic replacement may be refused since there is no prescription to cover the cost of an additional supply of the antibiotic.

Antibiotics For Children: Storage Recommendations And Expiry Dates

Amoxicillin oral solution for children

Amoxicillin is one of the most commonly prescribed antibiotics. Liquid Amoxicillin for children comes as a powder for oral suspension, which is mixed when a patient brings a prescription to the pharmacy. Forms of liquid Amoxicillin for children:

  • Amoxicillin 125mg/5ml oral suspension with sugar and sugar-free version of oral suspension
  • Amoxicillin 250mg/5ml oral suspension with sugar and sugar-free version of oral suspension

Do you have to refrigerate amoxicillin?

After reconstitution (mixing with water), liquid Amoxicillin needs to be refrigerated (2°C-8°C).

Amoxicillin oral solution expiry times

Once made up, the Amoxicillin solution usually has 7 a days shelf life. However, some sugar-free versions of Amoxicillin solutions for children have a shelf life of 14 days. Please check for expiry dates on the bottle of the product when you buy Amoxicillin.

Co-amoxiclav liquid antibiotic for children

Co-amoxiclav storage and expiry dates

Co-amoxiclav oral solution is also known under the brand name Augmentin. Co-amoxiclav and Augmentin come in the following strengths:

  • Co-amoxiclav 125/31.25 mg/5 ml Powder for Oral Suspension
  • Co-amoxiclav 250 mg/62.5 mg/5 ml Powder for Oral Suspension

Do I need to refrigerate a co-amoxiclav antibiotic for children?

Once made up into oral suspension, co-amoxiclav needs to be stored in the fridge at 2°C – 8°C.

Co-amoxiclav oral suspension expiry

Once mixed with water, co-amoxiclav suspension expires in 7 days. Augmentin, a branded co-amoxiclav solution, has 7 days expiry time after the reconstitution.

Flucloxacillin oral solution for children

Children’s flucloxacillin comes in the following forms:

  • Flucloxacillin 125mg/5ml Oral solution
  • Flucloxacillin 125mg/5ml Sugar-Free Powder for Oral Solution
  • Flucloxacillin 250mg/5ml Oral Solution
  • Flucloxacillin 250mg/5ml Sugar-Free Powder for Oral Solution

Do I have to keep the Flucloxacillin solution in the fridge?

All preparations of liquid flucloxacillin antibiotics for children should be kept in the fridge.

Flucloxacillin oral solution expiry times

Once mixed with water, the flucloxacillin oral solution has a shelf life of 7 days.

Phenoxymethylpenicillin oral solution storage and expiry times

Phenoxymethylpenicillin is available as sugar-free and sugar versions and comes in two different strengths:

  • Phenoxymethylpenicillin 125mg/5ml Oral Solution
  • Phenoxymethylpenicillin 250mg/5ml Oral Solution

Do I have to refrigerate Phenoxymethylpenicillin liquid antibiotic?

Once made up into oral solution (powder mixed with the water), Phenoxymethylpenicillin needs to be refrigerated at 2°C – 8°C.

Phenoxymethylpenicillin oral solution expiry

The sugar-free and sugared version of Phenoxy antibiotic solution for children has a shelf life of 7 days once made up.

Cefalexin oral suspension

Cefalexin liquid antibiotic is available in generic form and as branded medicine called Keflex. Cefalexin comes in two different strength formulations:

  • Cefalexin Oral Suspension 125mg/5ml
  • Cefalexin Oral Suspension 250mg/5ml

Storage instructions for Cefalexin oral suspension

The same storage instructions apply to both strength Cefalexin liquid antibiotics. Once made up, oral suspension needs to be kept in the fridge at 2-8°C (preferred) or a cool place (6°C-15°C).

Cefalexin Oral suspension expiry time

Generic Cefalexin oral suspension 125mg/5ml and 250mg/5ml) has a shelf life of 14 days. Keflex (a branded form of cefalexin oral suspension) should be used within 10 days after reconstitution.

Erythromycin liquid antibiotic for children

Erythromycin liquid comes in a variety of preparations, including sugar and sugar-free liquid forms.

  • Erythromycin 125 mg/5 ml Sugar-Free Granules for Oral Suspension
  • Erythromycin 250 mg/5 ml Sugar-Free Granules for Oral Suspension
  • Erythromycin 125mg/5ml Granules for Oral Suspension
  • Erythromycin 250 mg/5 ml Granules for Oral Suspension
  • Erythromycin 500mg/5ml Sugar-Free Granules for Oral suspension
  • Erythromycin 500 mg/5 ml Granules for Oral Suspension
  • Erythroped sugar-free 250mg/5ml
  • Erythroped sugar-free 500mg/5ml

There are some differences in storage recommendations between various forms of liquid erythromycin antibiotics.

Do I have to refrigerate Erythromycin antibiotics?

For Erythromycin 125mg/5ml, 250mg/5ml, 500mg/5ml sugar-free. Once made, store above sugar-free Erythromycin solutions at 2°C – 8°C (in a refrigerator). Some sugar-free versions of Erythromycin (for example, Erythroped) do not have specific storage recommendations. Once made up, a solution can be kept at room temperature. Erythroped is not commonly dispensed in community pharmacies.

Do I have to refrigerate erythromycin antibiotic

Erythromycin 125mg/5ml, 250mg/5ml, 500mg/5ml with sugar (syrup). Once made up, erythromycin syrup should be kept below 15°C (cool place) or fridge.

Erythromycin oral suspension expiry

Once made up, all preparations of erythromycin (sugar-free and sugar) have a shelf life of 14 days. Erythroped (a branded version of erythromycin) has a shelf life of 7 days.


Azithromycin liquid comes in two forms:

  • Azithromycin 200 mg/ 5 ml Powder for Oral Suspension
  • Zithromax Powder for Oral Suspension (a branded version of azithromycin 200mg/5ml)

Do I have to refrigerate Azithromycin?

Once made up, both reconstituted suspensions can be kept at room temperature. Do not store above 25°C.

Azithromycin expiry date

After reconstitution, generic Azithromycin 200mg/5ml oral suspension has a shelf-life of 10 days.

Once mixed with water, Zithromax Suspension has a shelf-life of 5 days.

Trimethoprim solution for children


Trimethoprim comes as a ready-made suspension containing 50mg of Trimethoprim per 5ml of solution (50 mg/5 ml).

Do you have to refrigerate Trimethoprim liquid antibiotics?

There is no specific storage recommendation for Trimethoprim liquid antibiotics. Once opened, Trimethoprim can be stored at room temperature.

Trimethoprim suspension for children expiry date

Product information for trimethoprim oral suspension does not specify any expiry dates once the suspension is open. This usually means that the product should not be used after the expiry date stated on the label or box.

Metronidazole oral suspension

Metronidazole Oral Suspension 200mg/5ml is not commonly prescribed in the community. Metronidazole comes as a ready-made solution.

How to store Metronidazole oral solution?

Metronidazole oral solution can be stored at room temperature. Do not store above 25°C. Once open, store recommendations are the same for Metronidazole liquid, meaning it can be stored at room temperature, not exceeding 25°C.

Metronidazole oral solution expiry date

Metronidazole oral solution should not be used after the expiry date, which is stated on the label and the box.

Antibiotic For Children: Where To Find Product Information Leaflets

Product information leaflets for all liquid antibiotics can be accessed on the EMC website.


How long is amoxicillin good for in the fridge?
Amoxicillin has a shelf life of 7 days. Some sugar-free versions of amoxicillin solution have 14 days shelf life. Expiry dates for antibiotics can be found on the dispensing label or product label which covers the bottle.
Do antibiotics go bad if not refrigerated?
Antibiotics should be refrigerated to ensure the stability and effectiveness of the drug. Inappropriate storage of antibiotics may result in the drug being less effective.
Should I store antibiotics in the fridge?
Some antibiotics need to be stored in the fridge whereas others don't. Read the dispensing label, product information leaflet or the product label on the bottle for storage instructions.
Should amoxicillin be stored in the fridge?
Once made up with water amoxicillin oral solution needs to be stored in the fridge.

Final words from Druggist:

Medicines tend to expire after the desired time. Every medicine has an expiry date, before that, one must use it. If at all the medicine is used after the expiry date, your child must be in danger, or the possibility would be that the medicine won’t work on the body.

Regarding children, the precautions parents take are tremendously good and should be handled with the utmost care.

Various antibiotic medicines are prescribed to children for their healthy being. Most antibiotics are preferred for children to treat conditions like bacterial infections. This shows a significant impact in curing the same.

It is always necessary for you to store the medicine in a proper place. If you do not store the medicine as advised, the drugs will not be as effective as they should be. Keep a clear vision of the medicine’s storage and expiry date before purchasing it.