Penicillin is a type of antibiotic that changed the medical world. Discovered in 1928 and later made into an antibiotic by a team lead by scientist Howard Florey, penicillin has saved lives by fighting many types of bacterial infection. Your doctor might prescribe penicillin for conditions such as ear infections and urinary tract infections.

Penicillin is an antibiotic

Penicillin is both the name of a single antibiotic and the name of a group of antibiotics. Other types of penicillin include:

• amoxicillin
• ampicillin
• benzylpenicillindicloxacillin
• flucloxacillin
• phenoxymethylpenicillin
• piperacillin

Penicillins work on many types of bacterial infection, unless the infection is resistant to it. They do not work on viral infections (such as colds and flu).

Your doctor might prescribe you a type of penicillin if you have a:

• skin infection
• dental infection
• ear infection
• an infection of the nose, throat or lungs
• urinary tract infection
• other bacterial infections

Tell your doctor if you have had an allergic reaction to any antibiotics in the past.

Penicillin side effects

All medicines have side effects, as well as benefits. The common side effects of penicillin are usually mild. You might experience:

• stomach ache
• diarrhoea
• nausea
• skin rashes and hives

Less common side effects include:

• shortness of breath or irregular breathing
• abdominal cramps, spasms, tenderness or pain
• vaginal itching and discharge, due to either a yeast infection or bacterial vaginosis

Serious side effects of penicillin are rare and include:

• difficulty breathing due to a severe allergic reaction (anaphylaxis)
• sudden and
• seizures

Call triple zero (000) and ask for an ambulance or ask someone to take you to the nearest emergency department immediately if you experience any serious side effects after taking penicillin (such as anaphylaxis).

Penicillin allergy

Some people are allergic to penicillin. If you get skin rashes, hives or mild wheezing after taking this medicine you might have a penicillin allergy.

If you have serious trouble breathing (heavy wheezing) or if your face start swelling, you might have penicillin anaphylaxis.

Managing penicillin allergy

Tell your doctor, dentist and all other health providers if you have had any symptoms of penicillin allergy. Your doctor might run further tests to confirm the severity of your allergy.

About 1 in 100 people has an allergy to penicillin, and about 1 in 3,000 people has a life-threatening allergic response to penicillin.

For more information

• For more information about penicillin allergy, contact the Australasian Society of Clinical Immunology and Allergy (ASCIA).
• Visit NPS MedicineWise for information about penicillin and other medicines. You can also call the NPS Medicines Line on 1300 633 424.
• If you’re experiencing any side effects and are not sure what to do, call the healthdirect helpline on 1800 022 222.