Phenoxymethylpenicillin at a glance
Medicine class
Penicillin beta-lactam antibiotic.
Available forms
Prescription-only tablets and oral liquids, including sugar-free liquids.
Food
Take on an empty stomach. Follow the product label because the specified gap after food differs between formulations.
Important allergy
Do not take it if you have a confirmed penicillin allergy.
What is Phenoxymethylpenicillin used for?
Licensed uses include susceptible, mild to moderately severe bacterial infections and specific forms of infection prevention.
Streptococcal infections, including bacterial pharyngitis, scarlet fever, erysipelas and other skin or soft-tissue infections.
Susceptible pneumococcal infections, including pneumonia and otitis media.
Vincent's gingivitis and pharyngitis.
Prevention of recurrent rheumatic fever or chorea.
Prevention of pneumococcal infection in people at increased risk, including those with asplenia or sickle cell disease.
Oral phenoxymethylpenicillin should not be relied upon for severe acute infection because absorption and blood concentrations may be inadequate or unpredictable.
How does Phenoxymethylpenicillin work?
It blocks proteins needed to build the bacterial cell wall, causing susceptible bacteria to break down. Bacteria producing penicillinase or other beta-lactamases may be resistant.
Phenoxymethylpenicillin preparations and strengths
Oral solution
Route: Oral
Strengths: 125 mg/5 mL, 250 mg/5 mL
Tablet
Route: Oral
Strengths: 250 mg, 500 mg
How to take Phenoxymethylpenicillin
Follow the dispensing label. Take it on an empty stomach: at least 30 minutes before food, or after the product-specific interval stated on the label or leaflet. Swallow tablets with water. Measure liquid with the supplied oral syringe or medicine spoon, not a kitchen teaspoon, and shake it when instructed.
Check that you have the correct liquid formulation before measuring it.
Keep reconstituted liquid refrigerated when directed by the label.
Do not share antibiotics with anyone else.
Phenoxymethylpenicillin side effects
Common or expected effects
- Feeling or being sick
- Diarrhoea
- Stomach discomfort or pain
- Skin rash or other mild hypersensitivity symptoms
Get urgent medical advice
- Anaphylaxis, including airway swelling, breathing difficulty or collapse
- Severe blistering or peeling skin reactions
- Severe, persistent or bloody diarrhoea suggesting antibiotic-associated colitis
- Rare blood-cell, liver, kidney or neurological reactions
Phenoxymethylpenicillin in pregnancy
Phenoxymethylpenicillin can be taken during pregnancy. Tell the prescriber if you are pregnant or planning pregnancy so they can confirm that an antibiotic is needed and choose an appropriate product.
Phenoxymethylpenicillin while breastfeeding
It is a preferred penicillin during breastfeeding because only negligible amounts are expected in milk. This applies most directly to healthy, full-term infants. Seek advice if the baby feeds poorly or develops diarrhoea, vomiting, thrush or a rash.
Phenoxymethylpenicillin interactions
Tell the prescriber or pharmacist about all medicines, vaccines, supplements and herbal products. Important examples include:
Methotrexate
Phenoxymethylpenicillin may reduce methotrexate clearance and increase toxicity risk; concurrent use requires prescriber review.
Warfarin and other coumarin anticoagulants
Anticoagulant control may change, so additional INR monitoring may be required.
Common questions about Phenoxymethylpenicillin
Answers are fully visible for fast scanning and source review.
Is phenoxymethylpenicillin the same as penicillin V?
Yes. Penicillin V is a commonly used name for phenoxymethylpenicillin.
Does it treat colds or flu?
No. It acts against susceptible bacteria, not viral infections such as colds or flu.
Can I drink alcohol while taking it?
Alcohol has no specific interaction with phenoxymethylpenicillin, although avoiding it may be sensible if the infection or medicine is making you feel unwell.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.