Chapter 12 -- Drugs, Microbes, Host - The Elements of Chemotherapy

Question 1

Chemotherapy

Answer 1

treating conditions with chemicals

Question 2

Antibiotics

Answer 2

chemical substances produced by living organisms that have antimicrobial activity usually molds, yeasts and bacteria

Question 3

Synthetic drugs

Answer 3

made in lab

Question 4

Semisynthetic drugs

Answer 4

made naturally but altered in lab

Question 5

Streptomyces sp.

Answer 5

produces most; best sources for ATB

Question 6

Broad spectrum

Answer 6

kills normal biota, GI issues, yeast infections

Question 7

Narrow

Answer 7

limited spectrum of activity

Question 8

Genetic changes

Answer 8

mutations followed by natural selection = chromosomal resistance

Question 9

Transfer of R plasmids

Answer 9

R= resistance; transformation, conjugation; transduction = extrachromosomal resistance

Question 10

Non genetic resistance

Answer 10

microbes persist in the tissues “out of reach” of antimicrobial agents; multiply; release progeny which is still susceptible to agent – not really resistant but just never touched by ATB

Question 11

Prophylaxis

Answer 11

drugs are administered to PREVENT infection in susceptible people

Question 12

Combined therapy

Answer 12

two or more drugs are given simultaneously, either to prevent the emergence of resistant species or to acheive synergism

Question 13

Synergism

Answer 13

combining drugs; you can use 1/10 concentration when used together – ex. TMP-SMZ

Question 14

Antagonism

Answer 14

medications that work against each other – ex. tetracycline and PCN

Question 15

Penicillin

Answer 15

acts on cell wall – beta-lactam ring; narrow spectrum – PCN G (gram +) requires injection; PCN V (gram +) PO

Question 16

penicillinase

Answer 16

beta-lactamase; causes development of bacterial resistance to drugs

Question 17

Cephalosporins

Answer 17

works on cell wall – broader spectrum that PCN - Cephalothin requires injection; has beta-lactam ring –

Question 18

Vancomycin

Answer 18

cell wall; used life threatening, methicillin resistant Staph infections

Question 19

Isoniazid

Answer 19

very narrow spectrum; inhibits synthesis of mycolic acid in cell wall of Mycobacterium

Question 20

Bacitracin

Answer 20

cell membrane; Gram + only – toxic to liver; topical

Question 21

Polymyxin

Answer 21

cell membrane; Gram - ; topical only

Question 22

Fluoroquinolones

Answer 22

Affects nucleic acid; levaquin - destroys normal flora - ruins ligament; diarrhea, C. diff, yeast infections

Question 23

Rifampin

Answer 23

affects nucleic acid; turns body fluids orange; inhibits synthesis on mRNA; used to treat Tb & leprosy

Question 24

Chloroquine

Answer 24

affects nucleic acid - treatment in malaria

Question 25

Capsofungin

Answer 25

anti-chitin drugs; inhibits fungal cell wall; echinocandins

Question 26

Ketoconazole

Answer 26

one of the first available oral treatments for systemic fungal infections - toxic to liver; best absorbed at high acidic level, so antacids cause decrease stomach acid levels and lowers drugs absorption -- S/E of med: decrease testosterone and helps treatment post operative erections after penile surgery

Question 27

Metronidazole

Answer 27

Flagyl; antiparasitic drugs -- also used for anaerobic bacteria

Question 28

Antihelminthic drugs

Answer 28

most effective drugs immobilize, disintegrate or inhibit metabolism of all stages of life cycle

Question 29

Niclosamide

Answer 29

drug of choice for tapeworms -- destoys scolex and adjoining proglottids of tapeworms

Question 30

Mebendazole

Answer 30

drug of choice of round worms; broad spectrum; work locally in intestines to inhibit microtubule or worms, eggs and larvae

Question 31

Antiviral drugs

Answer 31

most antiviral drugs have limited spectrum of activity, designed to block a step in viral multiplication

Question 32

HIV drugs

Answer 32

interfere with action of reverse transcriptase enzyme

Question 33

Broth dilution tests

Answer 33

bacteria in tubes; ATB added in different concentration -- look at 1st tube without growth -- take material from MIC tubes and try to grow again -- if no growth then its MDC; not MIC