What factors should be considered before the physician prescribes an antimicrobial agent?

1. where the infection is in the body and the likely microorganism causing the infection

2. patterns of antibiotic resistance both locally and nationally

3. the severity of illness

4. how prone the person to infection in general, eg. patient with cancer are particularly prone to infection

5. the risk of side effects with the antibiotic

6. history of Allergies

7. kidney and liver function

8. age, ethnic origin

And for women

9. pregnancy and breastfeeding

10. use of contraceptives. the effectiveness of hormonal contraceptives can be reduced by enzyme-inducing antibiotics, particularly if the antibiotic causes diarrhoea and additional precautions will be required