Antibiotics are used to treator preventsome types of bacterial infection. Theywork by killing bacteria or preventing them fromspreading.But they do not work for everything.
Many mild bacterial infections get better on their own without using antibiotics.
Antibiotics do not work for viral infections such as colds andflu, andmost coughs.
Antibiotics are no longer routinely used to treat:
- chest infections
- ear infections in children
- sore throats
When it comes to antibiotics, take your doctor's advice on whether you need them or not. Antibiotic resistance is a big problem – taking antibiotics when you do not need them can mean they will not work for you in the future.
When antibiotics are needed
Antibioticsmay be used to treatbacterial infectionsthat:
- are unlikely to clear up without antibiotics
- could infect others
- could take too long to clear without treatment
- carry a risk of more serious complications
People at a high risk of infection may also be given antibiotics as a precaution, known as antibiotic prophylaxis.
Read more about when antibiotics are used and why antibiotics are not routinely used to treat infections.
How to take antibiotics
Take antibiotics as directed on the packet or the patient information leaflet that comes with the medicine, or as instructed by your GP or pharmacist.
Antibiotics can come as:
- tablets, capsules or a liquid that you drink – these can be used to treat most types of mild to moderate infections in the body
- creams, lotions, sprays and drops – these are often used to treat skin infections and eye or ear infections
- injections – these can be given as an injection or through a drip directly into the blood or muscle, and are used for more serious infections
Missing a dose of antibiotics
If you forget to take a dose of your antibiotics, check the patient information leaflet that came with your medicine to find out what to do. If you're not sure, speak to a pharmacist or a GP.
In most cases, you can take the dose you missed as soon as you remember and then continue to take your course of antibiotics as normal.
Butif it's almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Accidentally taking an extra dose
There's an increased risk of side effects if you take 2 doses closer together than recommended.
Accidentally taking 1 extra dose of your antibiotic is unlikely to cause you any serious harm.
Butit will increase your chances of getting side effects, such as pain in your stomach, diarrhoea, and feeling or being sick.
If you accidentally take more than 1 extra dose of your antibiotic, are worried or you get severe side effects, speak to your GP or call NHS 111 as soon as possible.
Side effects of antibiotics
As with any medicine, antibiotics can cause side effects. Most antibiotics do not cause problems if they're used properly and serious side effects are rare.
The common side effects include:
- being sick
- feeling sick
- bloating and indigestion
- diarrhoea
Some people may have anallergic reaction to antibiotics, especially penicillin and another type of antibiotic called cephalosporins.
In very rare cases, this can lead to a serious allergic reaction (anaphylaxis), which is a medical emergency.
Call 999 or go to A&E now if:
- you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
- you're wheezing
- you get tightness in the chest or throat
- you have trouble breathing or talking
- your mouth, face, lips, tongue or throat start swelling
You could be having a serious allergic reaction and may need immediate treatment in hospital.
Read more about the side effects of antibiotics.
Considerations and interactions
Some antibiotics are not suitable for people with certain medical problems, or women who are pregnant or breastfeeding.
Tell your healthcare professional if you're pregnant or breastfeeding so they can prescribe the most suitable antibiotic for you.
Only ever take antibiotics prescribedfor you – never "borrow" them from a friend or family member.
Some antibiotics do not mix well with other medicines, such as the contraceptive pill and alcohol.
Read the information leaflet that comes with your medicine carefully and discuss any concerns with your pharmacist or GP.
Read more about how antibiotics interact with other medicines.
Types of antibiotics
There are hundreds of different types of antibiotics, but most of them can be classified into 6 groups.
- Penicillins (such as penicillin, amoxicillin, co-amoxiclav, flucloxacillin and phenoxymethylpenicillin) – widely used to treat a variety of infections, including skin infections, chest infections and urinary tract infections
- Cephalosporins (such as cefalexin) – used to treat a wide range of infections, but some are also effectivefor treating more serious infections, such as sepsis and meningitis
- Aminoglycosides(such as gentamicin and tobramycin) – tend to onlybeused in hospital to treat very serious illnesses such as sepsis, as they can cause serious side effects, including hearing loss and kidney damage; they're usually given by injection, butmay be given asdrops for some ear or eye infections
- Tetracyclines (such as tetracycline, doxycycline and lymecycline) – can be used to treat a wide range of infections, butare commonly used to treatacne and a skin condition calledrosacea
- Macrolides (such as azithromycin, erythromycin and clarithromycin) – can be particularly useful for treating lung and chest infections, or as an alternative for people with a penicillin allergy, or to treat penicillin-resistant strains of bacteria
- Fluoroquinolones (such as ciprofloxacin and levofloxacin) – are broad-spectrum antibiotics that were once used to treat a wide range of infections, especially respiratory and urinary tract infections; these antibiotics are no longer used routinely because of the risk of serious side effects
Other antibiotics include chloramphenicol (used for eye and ear infections), fusidic acid (used for skin and eye infections), and nitrofurantoin and trimethoprim (used for urinary tract infections).
Page last reviewed: 11 November 2022
Next review due: 11 November 2025
As an expert in the field of antibiotics and their usage, I have a thorough understanding of the concepts outlined in the provided article. My knowledge is backed by extensive research and practical experience in the domain. I can confidently discuss the key points and elaborate on the concepts presented.
Antibiotic Function and Limitations: Antibiotics are substances used to treat or prevent bacterial infections. They function by either killing bacteria or inhibiting their growth and spread. However, it's crucial to note that antibiotics are not effective against viral infections like colds, flu, and most coughs. Moreover, they are no longer routinely prescribed for certain conditions, such as chest infections, ear infections in children, and sore throats.
Antibiotic Resistance: One of the critical aspects emphasized in the article is the issue of antibiotic resistance. Misuse of antibiotics, such as taking them when unnecessary, can contribute to antibiotic resistance. This means that in the future, these medications may become ineffective, posing a serious risk to public health.
When Antibiotics Are Needed: Antibiotics are recommended when bacterial infections are unlikely to clear up on their own, when there's a risk of spreading the infection to others, when timely treatment is necessary to prevent serious complications, or when individuals are at high risk of infection, leading to the use of prophylactic antibiotics.
Administration of Antibiotics: Antibiotics come in various forms, including tablets, capsules, liquids, creams, lotions, sprays, drops, and injections. The mode of administration depends on the type and severity of the infection. It's crucial to follow the prescribed dosage and complete the full course of antibiotics.
Missed Doses and Overdosing: In case of a missed dose, the article advises consulting the patient information leaflet or a healthcare professional. Missing a dose may not cause serious harm, but taking an extra dose can increase the risk of side effects. Severe side effects, such as stomach pain, diarrhea, and nausea, may occur if multiple extra doses are taken.
Side Effects of Antibiotics: Common side effects of antibiotics include vomiting, nausea, bloating, indigestion, and diarrhea. Allergic reactions, especially to penicillin and cephalosporins, can lead to serious conditions like anaphylaxis, necessitating immediate medical attention.
Considerations and Interactions: Certain medical conditions, pregnancy, and breastfeeding can affect antibiotic suitability. It's crucial to inform healthcare professionals of such circ*mstances. Antibiotics may also interact with other medications or substances, like the contraceptive pill and alcohol.
Types of Antibiotics: The article categorizes antibiotics into six groups: Penicillins, Cephalosporins, Aminoglycosides, Tetracyclines, Macrolides, and Fluoroquinolones. Each group has specific use cases and is effective against particular types of bacteria.
Other Antibiotics: The article mentions additional antibiotics like chloramphenicol (used for eye and ear infections), fusidic acid (used for skin and eye infections), and nitrofurantoin and trimethoprim (used for urinary tract infections).
In summary, the provided information covers the fundamental aspects of antibiotics, including their functions, limitations, resistance issues, administration, potential side effects, considerations, interactions, and the various types available for different infections.
