Chemotherapy Flashcards
(30 cards)
What does the term chemotherapy refer to in modern medical practice?
The use of chemical substances to treat various aspects of disease.
Define chemotherapeutic agent.
Any chemical substance used in medical practice, also referred to as drugs.
What are antimicrobial agents?
A special group of chemotherapeutic agents used to treat diseases caused by microbes.
What is the meaning of antibiosis?
Against life.
What are antibiotics?
Chemical substances produced by microorganisms that inhibit the growth of bacteria.
Give examples of natural antibiotics.
- Streptomycin
- Neomycin
- Gentamycin
What are synthetic drugs?
Agents synthesized in the lab, such as sulfonamides, quinolones, and oxazolidinones.
What are semisynthetic drugs?
Synthetic precursors supplied to microorganisms that then complete the synthesis of the antibiotic.
Who discovered Salvarsan and for what purpose?
Paul Ehrlich discovered Salvarsan to treat syphilis.
What significant discovery did Alexander Fleming make?
He discovered that Penicillium notatum is able to inhibit the growth of microorganisms.
What is selective toxicity?
An antimicrobial drug’s ability to harm microbes without causing significant damage to the host.
What is the therapeutic dosage level?
The dosage that successfully eliminates the pathogenic organism if maintained over time.
Define chemotherapeutic index.
The relationship between an agent’s toxicity to the body and its toxicity to an infectious agent.
What is the difference between broad spectrum and narrow spectrum drugs?
Broad spectrum drugs are effective against a wide range of microorganisms, while narrow spectrum drugs are effective against a small number or single group.
What are the five modes of action of antimicrobials?
- Inhibition of cell wall synthesis
- Disruption of cell membrane function
- Inhibition of protein synthesis
- Inhibition of nucleic acid synthesis
- Action as antimetabolites
How do B-lactam antibiotics work?
They inhibit the synthesis of the peptidoglycan layer of bacterial cell walls.
What is the role of B-lactamase?
It hydrolyzes the B-lactam ring of antibiotics, rendering them ineffective.
What is the effect of polymyxins on bacteria?
They disrupt cell membrane function, particularly effective against G-negative bacteria.
How do aminoglycosides affect protein synthesis?
They act on the 30S ribosome, interfering with the translation of mRNA.
What is an antimetabolite?
A substance that affects the utilization of metabolites and prevents cells from carrying out necessary metabolic reactions.
What are the three categories of side effects from antimicrobial agents?
- Toxicity
- Allergy
- Disruption of normal flora
What is anaphylactic shock?
A serious life-threatening allergic reaction characterized by a sudden drop in blood pressure and narrowed airways.
What is superinfection?
The invasion by replacement microflora after disruption of normal microflora.
What are probiotics?
Live microorganisms that confer a health benefit on the host when administered in adequate amounts.
