Drugs

Any substance taken into the body that modifies or affects chemical reactions in body.

Some drugs are medicinal drugs used to treat symptoms or causes of a disease.

e.g., Antibiotics.

Primary site for drug metabolism is the liver.

Antibiotics

Antibiotics are chemical substance made by specific fungi in the Penicillium species, or bacteria that affects the working of bacterial cells, to disrupt their function or structure, preventing them to reproduce.

• It is effective against bacteria but not against viruses.
  • Antibiotic works by damaging and destroying the bacterial cell wall.
    • Viruses does not contain cell wall, only protein coat.

Target processes and structures that are specific to bacterial (prokaryotic) cells; as they do not generally harm animal cells.

Antibiotic Resistance

It is less effective because of overuse and being prescribed when not really necessary, patients failing to complete the fully prescribed course.

These resistant bacteria are commonly known as superbugs and most common one is MRSA.

Methicillin-resistant Staphylococcus Aureus (MRSA) infection is caused by a type of staph bacteria that's resistant to many antibiotics to treat ordinary staph infections.

The Process:

1. Variation, high number of bacteria and some of them are resistant to antibiotics.
2. The resistance is caused by mutations, and genetic changes.
3. The resistance trait to the specific antibiotic can be passed to other bacterias from one to the other through offspring or transfer of traits with its plasmid.
4. The resistant bacteria grew; reproduced.

Reference to Natural Selection.