Antibiotics concepts

Question 1

Antibiotics

Answer 1

They are medicines that are used to kill or stop the growth of microbial life in the body, such as bacterial infections, viral infections, fungal infections, and parasitic infections

Question 2

3 examples of indications for antibiotics

Answer 2

• Sepsis is a serious infection with high mortality and must be treated promptly
• Osteomilitis is a difficult to treat infection that requires an extended IV antibiotics course
• A sore throat is a less serious infection where antibiotics are only needed in high-risk cases. Most sore throats are associated with viral infections

Question 3

How do we know which antibiotic to choose to treat?

Answer 3

If we do not know the causative organism, it is recommended to choose the most appropriate antibiotic to be used until results are available. Once microbiology results are available, therapy can be targeted at the causative organism based on its antibiotic susceptibility (narrow-spectrum antibiotic)

Question 4

Difference between broad-spectrum and narrow-spectrum antibiotics

Answer 4

Broad-spectrum is for when we do not know the causative organism. For example, we know a bacterial infection is suspected but the group of bacteria is unknown (empiric therapy). This usually comes with adverse effects and can damage the body flora

Narrow-spectrum is when we know the causative organism. It reduces negative effects on the body’s natural flora and is more effective

Question 5

Adverse effects of antibiotics

Answer 5

• Common side effects: rash, nausea or diarrhea
• More serious reactions include immediate hypersensitivity (severe allergy)
• Risk of clostridium difficile infection is significantly raised in patients on broad-spectrum or multiple antibiotics, particularity when used for prolonged periods. Serious condition, especially with patients who are already unwell or frail. Some antibiotics are higher risk to cause C. diff
• Penicillin allergy

Question 6

6 causes of antibiotic resistance

Answer 6

Antibiotic resistance happens when bacteria change and become resistant to the antibiotics used to treat the infections they cause

1. Over-prescribing of antibiotics
2. Patients not finishing their treatments - gives bacteria time to proliferate as they did not all die
3. Over-use of antibiotics in livestock and fish farming
4. Poor infection control in hospitals and clinics
5. Lack of hygiene and poor sanitation
6. Lack of new antibiotics being developed

Question 7

How does antibiotic resistance occur?

Answer 7

1. Lots of germs. Few are drug resistant
2. Antibiotics kill bacteria causing the illness, as well as good bacteria protecting the body from infection
3. The drug-resistant bacteria are now allowed to grow and take over
4. Some bacteria give their drug-resistance to other bacteria through gene transfer, causing more problems

Question 8

3 types of the development of antibiotic resistance

Answer 8

1. Selective advantage - bacteria that contain resistance mechanisms can survive and multiply when exposed
   to antibiotics
2. Gene transfer - allows bacteria to share genes that cause antibiotics resistance
3. Cross-resistance - changes in bacteria which create resistance to one antibiotics may cause resistance to other antibiotics as well