Chapter 12

Question 1

what are the 3 principles of antimicrobial therapy?

Answer 1

*administering a drug to an infected person that destroys the infective agent without harming the host’s cells
*target infectious microbes by destroying/interfering microbial structures and enzymes
*produced naturally or synthetically

Question 2

antibiotics are common metabolic products of ___ and _____

Answer 2

aerobic bacteria and fungi

Question 3

what did Paul Ehrlich do?

Answer 3

coined the term chemotherapy to describe chemicals that would act as “magic bullets” and selectively kill pathogens

Question 4

who introduced the first “sulfa” drug?

Answer 4

Gerhard Domagk

Question 5

who was the first to discover a naturally produced antimicrobial, pcn, in 1928?

Answer 5

Alexander Fleming

Question 6

what is a chemotherapeutic agent?

Answer 6

any chemical used in the treatment, relief, or prophylaxis of a disease

Question 7

what is an antibiotic?

Answer 7

a metabolic product of one microorganism that inhibits or destroys other microorganisms.

Question 8

A drug that will kill a wide range of bacteria can be classified as a

Answer 8

broad spectrum

Question 9

A drug that will kill a few types of bacteria (limited) can be classified as a

Answer 9

narrow spectrum

Question 10

a drug that is made totally in the lab is considered___

Answer 10

synthetic

Question 11

a drug that is chemically modified in the lab after being isolated from the natural source is considered as

Answer 11

semisynthetic

Question 12

the amount of medication given during a certain time interval is the ____

Answer 12

dosage

Question 13

_____ is determined carefully to ensure the optimum therapeutic drug levels are achieved at the site of infection without causing significant toxicity (side effects) to the patient. allergic reactions and other potential S/E may still occur.

Answer 13

dosage

Question 14

what is the route of administration?

Answer 14

is the method used to introduce the drug into the body. Drugs that can be administered orally are generally preferred because the patients can more conveniently take the drugs at home

Question 15

when drugs cannot be absorbed in the GI tract, the drug is administered by a _____ route. (IV or IM injection)

Answer 15

parenteral

Question 15

antimicrobial drugs work in through what 5 different ways?

Answer 15

1. cell wall
2. cell membrane
3. protein synthesis
4. nucleic acid
5. cytoplasm

Question 16

describe how antimicrobial drugs work in the cell wall

Answer 16

peptidoglycan in the cell wall helps provide a rigid structure that protects against changes in the osmotic pressure in the environment. Active cells are constantly producing more peptidoglycan to place in the cell wall. Some drugs interfere with one or more of the enzymes required to compete this process, causing the cell to develop weak points at growth sites and to become osmotically fragile.
Examples: pcn and cephalosporins

Question 17

describe how antimicrobial drugs work in the cell membrane

Answer 17

damage to cell membrane causes disruption in metabolism or lysis. These drugs target a special type of lipids.
Examples: polymyxins, amphotericin B, nystatin

Question 18

describe how antimicrobial drugs work through protein synthesis

Answer 18

block transcription or translation
Examples: streptomycin, gentamicin, tetracyclines, chloramphenicol, erythromycin

Question 19

describe how antimicrobial drugs work in nucleic acid

Answer 19

block synthesis of nucelotides or replication. Examples: chloroquine and antiviral drugs like AZT

Question 20

describe how antimicrobial drugs work in the cytoplasm

Answer 20

prevent metabolic pathway
Examples: sulfonamides and trimethoprim

Question 21

fungal cells are eukaryotic; a drug that is toxic to fungal cells is also toxic to human cells

true or false

Answer 21

true

Question 22

antifungal drugs are divided to treat 2 types of disease ____ and _____

Answer 22

superficial and systemic

Question 23

what is the most common mode of action for antifungal drugs?

Answer 23

disrupting the cell membrane of the fungus

Question 24

name 4 different types of antifungal drugs

Answer 24

Polyenes, Allylamines, Fluconazole, Imidazoles

Question 25

describe Imidazole (antifungal drug)

Answer 25

otc with topical application include: miconazole, ketoconazole, clotrimazole found in otc products: Micatin, Lotrimin, Nizoral used for ringworm and vaginal yeast infections

Question 26

describe Fluconazole (antifungal drug)

Answer 26

orally or IV systemic yeast infections: oral thrush and cryptococcal meningitis

Question 27

describe Allylamines (antifungal drug)

Answer 27

most common, mostly used topically for ringworm brand name: Lamisil

Question 28

describe Polyenes (antifungal drug)

Answer 28

*Amphotericin B- used for systemic fungal infections = "Gold standard" *Nystatin- used topical or orally for treatment of yeast infections of skin, mouth or vagina

Question 29

what are the 4 major modes of action for antiviral drugs

Answer 29

*inhibition of viral release *inhibition of nucleic acid synthesis *inhibition of reverse transcriptase *inhibition of viral assembly or release

Question 30

antiviral drugs that inhibit viral release are

Answer 30

Amantadine (rimantadine), Tamiflu, and Relenza *used in the treatmetn of influenza infections, decreased flu symptoms and shorten duration

Question 31

antiviral drugs that inhibit nucleic acid synthesis

Answer 31

Acyclovir (zovirax)= Guanine analog (used to treat herpes inf. chickenpox & shingles) Ribavirin= Guanine analog (used to treat hepatitis and RSV)

Question 32

antiviral drugs that inhibit reverse transcriptase

Answer 32

AZT (azidothymidine) thymine analog, used to treat AIDS

Question 33

what are some major s/e people have after taking antimicrobial drugs

Answer 33

5% of people will experience s/e damage to tissues or toxicity: liver/kidney disruption in balance of normal flora= development of a superinfection ex: diarrhea, vaginal yeast inf.

Question 34

what are some considerations in selecting an Antimicrobial drug

Answer 34

*identify the microorganism causing the infection *test the microorganism's susceptibility to various drugs in vitro when indicated *overall medical condition of the patient

Question 35

what tests are used to test for drug susceptibility

Answer 35

Kirby-Bauer technique, tube dilution technique, E-test diffusion test