Antibiotics, also known as antibacterials, are medications that destroy or slow down the growth of bacteria.

They include a range of powerful drugs and are used to treat diseases caused by bacteria.

Antibiotics cannot treat viral infections, such as cold, flu, and most coughs.

This article will explain what antibiotics are, how they work, any potential side effects, and antibiotic resistance.

Fast facts on antibiotics

  • Alexander Fleming discovered penicillin, the first natural antibiotic, in 1928.
  • Antibiotics cannot fight viral infections.
  • Fleming predicted the rise of antibiotic resistance.
  • Antibiotics either kill or slow the growth of bacteria.
  • Side effects can include diarrhea, an upset stomach, and nausea.

Antibiotics commonly cause the following side effects:

Less common side effects of antibiotics include:

  • formation of kidney stones, when taking sulphonamides
  • abnormal blood clotting, when taking some cephalosporins)
  • sensitivity to sunlight, when taking tetracyclines
  • blood disorders, when taking trimethoprim
  • deafness, when taking erythromycin and the aminoglycosides

Some people, especially older adults, may experience bowel inflammation, which can lead to severe, bloody diarrhea.

In less common instances, penicillins, cephalosporins, and erythromycin can also cause inflamed bowels.

People must not stop a course of antibiotics halfway through. If in doubt, they can ask their doctor for advice.

People usually take antibiotics by mouth. However, doctors can administer them by injection or apply them directly to the part of the body with infection.

Most antibiotics start combating infection within a few hours. Complete the whole course of medication to prevent the return of the infection.

Stopping the medication before the course has finished increases the risk that the bacteria will become resistant to future treatments. The ones that survive will have had some exposure to the antibiotic and may consequently develop resistance to it.

An individual needs to complete the course of antibiotic treatment even after they see an improvement in symptoms.

Do not take some antibiotics with certain foods and drinks. Take others on an empty stomach, about an hour before meals, or 2 hours after. Follow the instructions correctly for the medication to be effective. People taking metronidazole should not drink alcohol.

Avoid dairy products when taking tetracyclines, as these might disrupt the absorption of the medication.