What Are Antibiotics & How Do They Work?

Antibiotics have changed the face of the medical world. Before their invention in 1928, bacterial infections such as pneumonia killed millions more people across the world each year!

Since then, antibiotics have transformed the treatment of infections, particularly when they started to become widely used in the late 1940s.

However, in recent years, GPs across the nation having been pushing the awareness that antibiotics don’t work for everything, and that we’ve become too dependent on them as a magical ‘cure-all’, so it’s important that you take them only when you have to.

Antibiotic pills

In this article, we discuss what antibiotics are, how they work, what they can treat, and how to avoid antibiotic resistance.

What are antibiotics?

Antibiotics are prescription drugs used to treat or prevent bacterial infections. They come in a range of different forms, including capsules, tablets, liquids, creams, ointments, and sometimes injections. Different antibiotics treat different infections.

How do antibiotics work?

By disrupting bacteria reproduction, attacking its surrounding wall, or slowing protein production in bacteria, antibiotics are able to kill the bacteria causing the infection or stop it from growing.

What do antibiotics treat?

As mentioned, antibiotics are used to treat bacterial infections; like urinary tract infections (UTIs), sinus, ear, throat infections; and meningitis. They cannot treat viruses, and therefore should not be used for common colds, flu or COVID, yeast infections, or ringworm.

A healthcare professional will assess your symptoms and determine whether or not an antibiotic should be prescribed you.

Related: What is an NHS repeat prescription?

How long do antibiotics take to work?

Antibiotics work instantly, but you may not start feeling better until a couple of days into your treatment. How quickly antibiotics work can depend on which antibiotics you are taking and the type/intensity of the infection you are treating.

How long do antibiotics stay in your system?

How long antibiotics stay in your system depends on the type of antibiotic you are taking, plus additional factors like dosage, metabolic rate, age, and body mass. Common antibiotics may stay in your system for up to 24 hours after your final dose. But, you’re best off speak to your doctor for timings on your specific antibiotic.

How to take antibiotics

Most antibiotics should be taken for between 7 and 14 days. However, sometimes shorter courses are prescribed. You should take your antibiotics in regular doses according to your treatment plan. Your doctor will recommend the correct course of treatment for you but always remember to read the drug label carefully beforehand as well.

Suggested: New Medicine Service

It’s important to note that even if you feel recovered after a few days into your treatment, you should always finish the full course or antibiotics prescribed to fully resolve your infection and prevent antibiotic resistance.

Taking antibiotics on an empty stomach is recommended for some types of antibiotics but not others, make sure to consult your doctor if you’re unsure.

Hey Pharmacist will tell you the recommended dosage for your medication once you add repeat prescription to your profile.

Antibiotic side effects

As with most medications, antibiotics can have side effects. It’s good to be aware of these so that you can prepare for them in case you experience any of them. The most common are:

  • Mild skin rash or allergic reaction
  • Feeling sick or being sick
  • Bloating or indigestion
  • Diarrhoea
  • Loss of appetite

Below are rarer antibiotic side effects:

  • Anaphylaxis (including wheezing, shortness of breath and facial swelling)
  • Stomach cramps
  • Yeast infections in the mouth or vagina
Antibiotics tub with pills spilling out

Can you drink alcohol on antibiotics?

It’s sensible to avoid alcohol whilst you are completing a course of antibiotics, in order to let your body heal efficiently. However, it is generally fine to drink alcohol on antibiotics as long as it is in moderation.

However, there are some antibiotics on which you CANNOT drink alcohol. This includes:

  • Metronidazole
  • Tinidazole
  • Trimethoprim-sulfamethoxazole

Drinking alcohol with these antibiotics can cause nausea, headaches, dizziness, irregular heartbeat and vomiting. Always read the label on your antibiotics to make sure.

What is antibiotic resistance?

The overuse of antibiotics over the years can result in antibiotic resistance, whereby bacteria develops the ability to defeat antibiotics and continue to grow. The bacteria itself becomes resistant, then infects humans and animals and is much harder to treat.

This has led to the emergence of so-called ‘superbugs’ – serious illnesses such as tuberculosis, typhoid fever and pneumonia, that antibiotics are now failing to cure because of the resistance the bugs have developed.

Antibiotic resistance (also known as antimicrobial resistance) is very serious. For example, if you were having a minor procedure at the hospital or your doctor’s surgery, you would usually be given a course of antibiotics to prevent infection. Superbugs are resistant to these drugs, which can cause dangerous and even life-threatening infections.

Therefore, you should only take antibiotics if prescribed. Antibiotics are the very last choice for the treatment of cold or flu and will only be prescribed if there are complications because you’ve got a bacterial infection. If the doctor thinks antibiotics are necessary, they will prescribe them, you shouldn’t ask for them.

Below, we have included the TV ad campaign "Keep Antibiotics Working" which is part of a government strategy to alert the public of the risk of antibiotic resistance.

S.M.A.R.T antibiotic use

Antibiotics are a unique drug, as the more they are used, the less effective they become. A UK study funded by Public Health England in 2018 found that up to a fifth of antibiotic prescriptions may have been given needlessly.

So, it’s vital that when you are prescribed them, you take them correctly:

Superbugs - The over-prescription of antibiotics for common viruses such as sore throats (which antibiotics are not effective for 95% of) has led to the emergence of ‘Superbugs’ – strains of bacteria that are resistant to many types of antibiotics.

Most viruses get better on their own without using antibiotics, as do some mild bacterial infections. If in doubt, call NHS 111 for advice.

Always finish your prescription - if you are prescribed antibiotics, it’s essential that you take them as prescribed, and always finish the full course, even if you feel better.

Runny noses, colds, sore throats and flu - these are just some of the viruses which do not normally need treating with antibiotics as they’ll get better without prescription drugs. Using antibiotics when they’re not needed can have unpleasant side effects (such as an upset tummy).

Treat yourself at home - if you have a temperature, drink plenty of water and replace any lost fluids with electrolytes (typically a product such as Dioralyte). For headaches and pain relief, take paracetamol or ibuprofen. These can be taken together as long as you stick within the limits detailed on the pack.

TIP: If you have a sore throat, ask your pharmacist for lozenges, which will numb the pain and reduce inflammation. Home remedies such as freshly squeezed lemon juice and a teaspoon of honey in hot water can also help to soothe an irritating cough.

How to take antibiotics

In summary, only take antibiotics when you have been prescribed them by your doctor and make sure that you take the course correctly.

Having read this, you should now be all clued up on what antibiotics are, how to take them, the side effects, whether you can drink alcohol and how to limit the effects of antibiotic resistance, but if you are at all unsure, speak to a medical professional, like your local pharmacist or GP.