Question

1. Define chemotherapy, antibiotic, and antimicrobial agent. (1b). Describe the rationale for combination therapy.

Answer 1

Chemotherapy uses chemicals/drugs to kill cancer cells and has proven to be much effective when the tumors are impossible to remove surgically. Chemotherapy also helps to suppress tumor growth after surgery or radiation treatment. Chemotherapy uses different types of chemicals, including plant derived, animal derived and manmade to kill cancer cells either by same or different mechanisms. These chemo drugs are grouped according to their mode of action, chemical structure and their relationship to other drugs . Alkylating agents like cisplatin and carboplatin keep the cell from reproducing by damaging its DNA. These drugs work in all phases of the cell cycle and are used to treat many different cancers, including cancers of the lung, breast, and ovary as well as leukemia and lymphomas. Antimetabolites like 5-fluorouracil (5-FU) and 6-mercaptopurine (6-MP) interfere with DNA and RNA growth by substituting for the normal building blocks of RNA and DNA.

An antimicrobial is an agent that kills microorganisms or stops their growth.Antimicrobial medicines can be grouped according to the microorganisms they act primarily against.Antifungals act against fungus and yeast, anti bacterials act against bacteria and anti virals acts against viruses.

Antibiotics are antimicrobial agents that are used against bacteria.In cancers ,Actinomycin-D and Mitomycin-D are the other anti-tumor antibiotics used which functions similar to anthracyclins.

Combination therapy includes combinations of chemotherapy , anti microbials, surgery and radiation etc to decrease the spread of cancers. They are much more effective than simple relying on either one of the treatments.